LARSEN and LIENERT 2007 Novaquatis final report

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LARSEN and LIENERT 2007 Novaquatis final report
A New Approach to Urban Water Management
Final Report Novaquatis
Nova 1
Nova 6
Nova 2
Nova 7
Nova 8
Nova 5
Nova 3
Nova PP
Nova 4
Process engineering
Introduction. The NoMix technology promotes water pollution control and conserves resources. Public attitudes to
this innovation are favourable. Various methods have been developed for treating urine and removing micropollutants.
Urine transport remains problematic. The results of the Novaquatis project suggest that it would be worth finding solutions
to this problem – or avoiding it altogether by treating urine directly on site. For urine source separation could make a
significant contribution to resolving the world’s increasingly serious water pollution control issues.
Nova 1: Is the NoMix toilet acceptable? An innovation for private bathrooms can only be widely
implemented if it is accepted by the public. For this reason, all Swiss NoMix pilot projects were accompanied by
sociological studies. 1750 people were surveyed – and their attitudes towards urine source separation are
highly favourable. Despite a number of deficiencies, the NoMix toilet is well accepted, especially in public buildings. Further
development efforts are now required on the part of the sanitary industry. Currently available models can, however, also
be used – with careful supporting measures – in order to contribute to further improvements in urine source separation.
Nova 2: Does the sanitary technology work? The principle of NoMix is simple: urine is collected
separately from other wastewater. But, in practice, this is still not as simple as it sounds – especially when
it comes to sanitary technology. For example, pipes may be blocked by urine scale, and designing and producing
a modern NoMix appliance is a costly enterprise. Novaquatis approached these problems in various ways: through
research on precipitation, feedback from pilot projects and round-table discussions to explore the interests of the parties
Nova 3: Storage and transport. The key problem for the NoMix system is how urine is to be transported from the toilet to a central treatment plant. Nova 3 proposes transitional solutions that would allow
the NoMix technology to be integrated into the existing wastewater management system and further
developed: after temporary storage, urine is transported via the sewer system. Implementation of the NoMix technology
in practice is supported by a newly developed computer model. One important finding is that only 60–75 % of urine
excreted is collected by today’s NoMix toilets.
Final Report of the Transdisciplinary Project Novaquatis
Nova 4: Urine treatment and fertilizer production. Urine contains high levels of nutrients –
and these should not be allowed to enter waterbodies. One attractive option, therefore, could be to recover
nutrients for use as fertilizers in agriculture. Novaquatis studied a broad range of processes – biological,
chemical and physical – both for the production of fertilizers and for the removal of nutrients. It was shown that the various
processes are suitable for different purposes and, in most cases, are not energy-intensive. This means that treatment
can be adapted to meet specific requirements.
Nova 5: Are micropollutants in urine problematic? On average, for all medicines and
hormones ingested, 60–70 % of the active ingredient is excreted in the urine – with major differences between
individual compounds. But in a urine-based fertilizer, micropollutants are undesirable. As has been shown
by chemical and ecotoxicological analytical tests, these substances can be removed from urine by certain treatment
processes. Separate treatment of urine would be beneficial for water pollution control since it would reduce the
ecotoxicological hazard potential posed by pharmaceuticals in wastewater by an estimated 50 %.
Nova 6: Urine-based fertilizers? The nitrogen, phosphorus and potassium required for Swiss
agriculture is now largely provided by artificial fertilizers. Urine-based fertilizers could be used as a substitute for
15–37 % of the total. In surveys, farmers and consumers are in favour of the idea – provided that health risks
are excluded. Experiments from Nova 4 showed that urine-based products are as effective as artificial fertilizers. But before
they can be introduced on a large scale, a careful assessment of costs and benefits – and elaborate approval procedures –
will be required.
Nova 7: Evaluation. Nova 7 evaluates the impacts of the NoMix technology on urban wastewater
management, focusing on two aspects – water pollution control and nutrient recycling. Essentially, a positive
view is taken of the new concept – both globally and with regard to Europe. The NoMix technology increases
the energy efficiency of the entire system, compared with conventional processes. In addition, it has the potential
ultimately to become economically competitive.
Nova 8: NoMix technology for fast-industrialising countries? The introduction of flush
toilets in fast-industrialising countries often has a devastating impact on the environment, owing to the lack of
appropriate wastewater treatment measures. In the Chinese city of Kunming, situated in the basin of the heavily
polluted Lake Dianchi, the potential for treatment at sewage plants is virtually exhausted. If water quality is to be improved,
measures such as urine source separation will be required. Stakeholders’ attitudes towards the NoMix technology
are highly positive – which could pave the way for the large-scale implementation of this system.
Pilot projects: Does NoMix work in real life? Pilot projects involving NoMix toilets are
challenging, since these lavatories do not (yet) function as smoothly as conventional models. However, to
permit further development, they need to be tested in practice. In Switzerland, four pilot projects were carried
out in apartments and public buildings. It was concluded that while it is certainly possible to introduce NoMix toilets,
close monitoring of the process is required. In addition, projects in private households are more problematic than in public
settings. The experience gained is of great importance both for the development of the technology and for practical
Practical guide: Would a NoMix toilet be a suitable option for me? NoMix is not yet a mature
technology. Certain elements of the system, such as urine treatment, have not progressed beyond the laboratory stage.
While the sanitary technology is already available, NoMix toilets do not meet the standard of conventional models in
various respects, and they require careful maintenance. A NoMix toilet should therefore only be installed after due
consideration of all aspects, and the project objectives should be clearly defined from the outset. The experience gained
from Novaquatis can help to ensure that NoMix installations are properly planned.
People in charge
Final Report of the Transdisciplinary Project Novaquatis
Beyond end-of-pipe solutions: There are alternatives to wastewater treatment
plants for pollution control (Photo Abwasserverband Altenrhein)
Green isn’t always beneficial: The NoMix technology could rapidly help to
resolve nutrient overload issues in coastal waters (Photo Keystone)
The NoMix technology has major potential. However, the
costs need to be competitive with conventional technologies,
since problems of water pollution control and phosphorus recycling to agriculture can often also be addressed using conventional
In Novaquatis, we studied whether, in what form and in what
circumstances the NoMix technology is a viable option. As a wide
range of questions are involved, the projects were organized into
work packages reflecting the stages of a possible nutrient cycle.
An overview is given on pp. 2–3, and further details can be found
in the individual Novaquatis publications (see pp. 26–28).
Research background
(Tove A. Larsen, Judit Lienert)
Urine source separation is based on a simple insight: most of the
nutrients in wastewater – about 80 % of the nitrogen and 50 %
of the phosphorus – derive from urine, which itself accounts for
less than 1 % of the total volume of wastewater. In the twentieth
century, wastewater treatment plants in Europe were expanded
specifically to deal with these nutrients, as they produced toxic
effects (e.g. ammonium in rivers) or excessive algal growth (e.g.
phosphorus in lakes). At treatment plants, major efforts were
undertaken to precipitate phosphorus, to convert ammonium to
nitrate and to then eliminate the latter.
The “NoMix technology” concept is also simple: urine is collected in the front compartment of specially designed toilets and
drained, with a little flushing water or even undiluted, into a local
storage tank. The back compartment of these toilets operates
on the same principle as conventional models; the waste matter collected is flushed into the sewers with water. One of the
Novaquatis research topics was how urine is to be subsequently
managed: the nutrients nitrogen and phosphorus are used to produce a fertilizer – or are removed by processes similar to those
applied at wastewater treatment plants.
Separating urine from wastewater would offer various advantages: wastewater treatment plants could again be built on a
smaller scale, and at the same time waterbodies could be more
effectively protected from nitrogen and phosphorus inputs. The
nutrients could be recycled to agriculture, and the micropollutants in urine – hormones and pharmaceutical residues – could
be removed without being mixed with wastewater. Urine source
separation would thus clearly increase the flexibility of waste­water
treatment. In the face of global water scarcity, the NoMix technology also represents an excellent way of improving the quality of
reused water.
Final Report of the Transdisciplinary Project Novaquatis
Results and synthesis
Gratifyingly, the NoMix technology meets with a high level of
approval among the public. All the people surveyed in Novaquatis
were familiar with and had used the still-immature technology.
Although they recognized the drawbacks of today’s NoMix toilets, the overwhelming majority found the basic idea convincing
(Nova 1). Practitioners also show considerable interest: in Canton
Basel-Landschaft, for example, large-scale pilot projects were
successfully conducted (Nova PP). With regard to conservation
of resources, the NoMix technology also performs well: it has the
potential to make a major contribution to water pollution control
in an energy-efficient manner. In addition, in areas of nutrient
scarcity, urine represents a local nutrient resource (Nova 7).
The difficulties are in the detail, and urine transport proved to
be the most problematic point. Installing new pipes or transporting
urine by tanker from basement storage tanks for centralized treatment would be a complex and costly undertaking. In Novaquatis,
we elaborated low-cost solutions for transporting urine via the
existing sewer system (Nova 3). However, despite their potential, they failed to convince the project partners from the sanitary
technology industry. These approaches are too closely tailored
to Swiss conditions and are also only suitable for relatively small
catchment areas. The sanitary industry therefore considers the
market potential to be too low to justify investments in the NoMix
Major potential: Urine source separation could spell big business for the
sanitary industry (Photo Keystone)
Problem or opportunity? Nutrients from urine are unwelcome in waterbodies,
but useful as fertilizers (Photo Andri Bryner)
technology (Nova 2). Improved sanitary technology is, however,
indispensable; although pilot projects can be carried out with
today’s NoMix toilets – larger-scale demonstration projects are not
feasible (Nova PP). The objections raised by the sanitary industry
will thus have a decisive influence on future developments.
At the same time, literature studies (Nova 7) indicated the
huge potential of the NoMix technology from a global perspective.
Coastal waters in particular are severely threatened by nutrient
overload. As a result of explosive population growth in these
regions, the problems associated with nutrients from waste­water
are becoming increasingly prominent on the global agenda.
Greater elimination of nutrients is required – which is at present
being carried out almost exclusively in industrialized countries. In
areas currently lacking a fully developed infrastructure, the NoMix
technology can protect water resources more rapidly and effectively than the expansion of sewers and treatment plants. The
potential of the NoMix technology in cases where acute population
pressures give rise to intractable water pollution control problems
was impressively demonstrated by the example of China (Nova
Ultimately, the key issues are cost-effectiveness and the technical and organizational possibilities of urine source separation.
If urine could be readily transported, centralized urine treatment
would be the option of choice. Methods already exist (Nova 4),
and processes such as phosphorus precipitation and biological
nitrogen elimination can be applied much more cheaply and
energy-efficiently to concentrated urine than to wastewater.
Great potential also attaches to methods for the recovery of
nitrogen and elimination of micropollutants – pharmaceuticals and
hormones excreted by humans and detectable in waterbodies.
Urine in wastewater accounts for an estimated 50 % of the
ecotoxicological hazard posed by these substances (Nova 5).
Given the difficulties and /or cost of transport, the potential
and cost-effectiveness of decentralized processes need to be
considered. Urine treatment on site appears to be an attractive option. However, it was not possible within the Novaquatis
project to study decentralized processes in detail. Here, too, the
combination of phosphorus precipitation and biological nitrogen
elimination would certainly be a promising approach. We are confident that mass production could make decentralized processes
economically attractive for the sanitary and other industries. More
problematic, in our view, is the stability of decentralized technologies and the level of maintenance required, especially in the case
of biological processes. To facilitate the adoption of the NoMix
technology, the two types of solution could be pursued in parallel.
In view of Eawag’s scientific expertise, we are better qualified to
develop stable biological processes and solutions for the organiza­
tional problems of decentralized treatment than to identify new
options for urine transport.
The Novaquatis research showed that the NoMix technology could
represent a valuable alternative to nutrient elimination as practised
today – provided that one of the two fundamental problems is
solved: either an attractive, widely applicable and low-cost solution
needs to be found for urine transport, or stable and cost-effective
technologies need to be developed for decentralized treatment.
Water pollution due to nutrient emissions is an increasingly
serious problem worldwide, and we are convinced that it is worth
seeking solutions. However, to be competitive, innovations require
large markets. It may therefore be advisable initially to develop
technologies for fast-growing urban areas where nutrient elimination at wastewater treatment plants is inadequate or non-existent.
In this way, the NoMix technology could rapidly and effectively
help to resolve global water pollution issues. This would require
the development of attractive and economic technologies – e. g.
by Swiss companies, which increasingly operate in global markets. As solutions of this kind also represent a realistic option for
industrialized countries, implementation of the NoMix technology
in demonstration projects would make sense here, too. In the long
term, Swiss waterbodies would also benefit from the widespread
application of this system.
Final Report of the Transdisciplinary Project Novaquatis
A door to the future? (Photo Yvonne Lehnhard)
Work package Nova 1
Research background
Nova 1 focuses on peoples’ attitudes towards the NoMix technology. To date, new technologies have been developed by
waste­­water management experts without the participation of
the public. However, wastewater separation in private bathrooms
concerns every individual. Accordingly, both practitioners and
­users of NoMix toilets were involved at a very early stage of the
Novaquatis research programme in order to determine how this
innovation is viewed by the public.
Nova 1 involved scientific studies accompanying all the pilot
projects in Switzerland. It identified the deficiencies of the NoMix
technology and explored questions such as: Are NoMix toilets
accepted? Is the design well received? Do the NoMix toilets smell
unpleasant? Do users adapt their behaviour? How can the NoMix
technology be diffused? What factors would promote the success
of further NoMix pilot projects?
Nova 1-1: Consumer attitudes
(Claudia Pahl-Wostl)
Initial data on the acceptability of NoMix toilets in households was
provided by a citizen focus group study involving 44 volunteers
[1]. The participants were introduced to the complexities of urine
source separation with the aid of an interactive Web tool (www.
novaquatis.eawag.ch/tool/index_EN) and took part in moderated group discussions. In addition, they visited a NoMix toilet at
The most important findings were that 79 % believe the NoMix
toilet to be a good idea, and 84 % would move into an apartment
fitted with a NoMix toilet – although the costs, maintenance and
cleaning efforts required should not be significantly higher than for
conventional toilets. Food produced with urine-based fertilizers
would be bought by 72 %, provided that health risks are excluded.
Relatively little importance tends to be attached by the participants to sustainable development – e. g. closing of nutrient
cycles. More important, in their view, is knowledge of any health
risks associated with micropollutants in urine-based fertilizers.
Consequently, efforts to minimize such risks are of the greatest
Final Report of the Transdisciplinary Project Novaquatis
relevance in ensuring that the NoMix technology is accepted by
Many of these findings are confirmed by the quantitative surveys conducted for the pilot projects in public buildings. However,
the qualitative results from Nova 1-2 and the pilot project in households indicate that having a NoMix toilet in a private bathroom is
not, in practice, unproblematic.
Nova 1-2: Cultural psychology
(Ruth Kaufmann-Hayoz, Kirsten Thiemann)
Nova 1-2 forms part of a doctoral thesis on sustainable product
design [2]. On the basis of theoretical considerations and a case
study, the relevance of technological innovations to well-being
was investigated. As well as exploring historical, collective /cultural developments in the sanitation field and personal bathroom
culture, the case study was concerned with the introduction of
NoMix toilets at a vocational college and in four private apartments.
As shown by the theoretical investigations, it is difficult to
introduce technological innovations that are not in conformity
with human culture. One problematic aspect of this process is
the sense of being subject to the will of others, e. g. if NoMix
toilets are installed in an apartment without the tenants’ explicit
This experience in private apartments led to specific recommendations for the improvement and widespread acceptance of
the NoMix toilet. The residents’ reactions varied widely: some
are sceptical, others approve of the NoMix toilet, particularly for
environ­mental reasons, and are happy to use it. Usage of the
NoMix toilet is heavily dependent on individual factors such as
habits or ergonomics. While some men always sit to urinate,
­others never do so. The correct sitting position is difficult for many
women and especially for children to adopt. The cleaning effort
required is generally considered to be relatively large. In addition,
it would be ideal if it were possible to select from a range of
NoMix toilets with a variety of colours, designs, sitting positions
and flushing systems.
Nova 1 – Acceptance
Gentlemen, please be seated: The NoMix toilet only works if it’s correctly
used – but you’re allowed to read the paper (Photo Ruedi Keller)
And, how was it? For 80 % of the users surveyed, the NoMix toilet is at least
as good as conventional models (Photo Ruedi Keller)
Nova 1-3: Acceptance and diffusion
(Judit Lienert, Tove A. Larsen)
Nova 1-3 used quantitative studies to assess the acceptance of
the NoMix technology among larger target groups and investiga­
ted how it could be further diffused. Surveys were conducted for
all three Swiss pilot projects in public buildings: at a vocational
college (534 respondents), at Eawag (715) and at the Basel-Landschaft cantonal library (501). The results are representative for
users of buildings of this kind (e. g. vocational college students in
German-speaking Switzerland).
Acceptance levels were very high in all cases. Urine source
separation was considered a good idea by 72 % of respondents
at the vocational college and Eawag, and 86 % would move into
an apartment fitted with a NoMix toilet [3, 4]. Around 80 % rated
NoMix toilets as equivalent or superior to conventional toilets with
regard to design, hygiene and odour. While the NoMix technology
only works if the toilet is correctly used, most of the respondents
were prepared to adapt their behaviour; for example, 72 % sat to
urinate. These findings were confirmed by the survey at the BL
cantonal library (not yet published).
Theoretically objective factors (e. g. odour) are often subjec­­
tively perceived in practice. Acceptance thus depends not only on
clean sanitary facilities but also on information, discussions with
peers and personal attitudes. Effective communication therefore
has a decisive influence on project outcomes.
The NoMix technology is linked to the entire wastewater
manage­ment system – from toilet to treatment plant. A high level
of acceptance among toilet users in itself offers no guarantee that
the innovation will be widely adopted in practice. What is crucial,
rather, is to gain the support of wastewater professionals – as
was shown by an analysis based on diffusion theory [5]. Urban
wastewater management experts will have to introduce the new
system and bear many of the consequences. Scientists, for their
part, will need to provide mature solutions capable of winning
the commitment of professionals to further develop the NoMix
system in practice.
The results from Nova 1 make it possible to assess how the Swiss
public could react to the NoMix technology. It will probably be
widely accepted if it meets modern sanitary standards and is safe
and not too expensive. However, given the drawbacks of current
NoMix toilets, large-scale implementation cannot yet be recommended; the toilets first need to be optimized by the sanitary
firms (Nova 2). Our experience indicates that while further pilot
projects are still possible with the immature technology, careful
supporting measures will be required. Such projects are trickier in
homes than in public buildings, where maintenance is performed
by technical staff. As the next step, diffusion pathways for the
NoMix technology should be investigated and market niches
identified where it can be implemented and refined. The public is
prepared to give this unconventional technology a chance.
Final Report of the Transdisciplinary Project Novaquatis
The bowl of the future (Photo Yvonne Lehnhard)
Work package Nova 2
Research background
The modern water-flush NoMix toilet was invented in Sweden in
the 1990s. The principle is straightforward: when the user sits on
the toilet, urine is collected at the front and drained into a separate
tank, while at the back the faeces are flushed away in the normal
manner. The appliance thus, in effect, consists of a toilet with a
built-in urinal.
But this simple principle involves certain practical difficulties.
As in the case of waterfree urinals, mineral deposits – popularly
known as urine scale – build up over time, and pipes may be
blocked as a result.
This and other sanitary technology-related problems raise a
number of questions: How can clogging of the pipes be avoided?
On a NoMix toilet, what sitting position is both comfortable and
functional? Does separation work in practice? Does this kind of
toilet fit in with a modern bathroom, or does it look anachronistic
and old-fashioned? If necessary, how can NoMix toilets be improved?
In the overall NoMix system, the new toilet technology plays
a significant role. Answers to the above questions were sought in
several Novaquatis work packages: Nova 1 (how do users react to
the technology?), Nova 2-1 (how can innovations be achieved?),
Nova 2-2 (how does precipitation arise?), Nova 3 (is source separation successful?), Nova PP (can pilot projects already be carried
out with existing NoMix toilets?).
A number of conclusions can be drawn from the various
projects: although the existing NoMix toilets are not perfect, it is
certainly possible to use them in pilot projects (Nova 1, Nova PP).
The major problem of precipitation remains unresolved (Nova 2-2).
There are thus good reasons to pursue further development of the
NoMix toilets (Nova 2-1).
Novaquatis pilot projects, and the new Eawag building is fitted
exclusively with the Roediger NoMix toilet, in addition to a variety
of waterfree urinals. The experience gained through Novaquatis
was communi­cated to the manufacturer and should now provide
a basis for the development of a new-generation, functionally
enhanced Roediger NoMix toilet (cf. “Practical guide”).
With today’s sanitary technology, pilot projects are practicable at workplaces, for example, but in private households they
remain problematic (Nova PP). However, the system can only be
developed to maturity through large-scale pilot and demonstration
projects. In round-table discussions at four workshops involving
representatives of the sanitary and wastewater sector, we explored what was required to enable an optimal NoMix toilet to
be introduced. It transpired that, for the companies concerned,
a clear definition of the initial markets is indispensable. These
also need to be sufficiently large to make commercial production
worthwhile. Major markets are to be found where major problems
exist. As well as rapidly expanding cities in fast-industrialising
countries (Nova 8), this could include water-scarce regions such
as Australia or China. In contrast, the step-by-step approach envisaged in Swiss transition scenarios (Nova 3) is unattractive for the
industrial partners, as the market is judged to be too small. In
addition, the development process is complicated by the large
number of parties involved. As previously noted [1], if companies
are to be prepared to make more substantial investments, it is
crucial that wastewater professionals should begin to take a much
greater interest in the NoMix technology. Essentially, the sanitary industry is interested and considers the task to be feasible.
However, all the solutions entail additional costs, and since these
are incurred by households, while the savings are made by local
authorities, the costs would have to be transferred through an
ingenious financing model.
Nova 2-1: Cooperation with the sanitary industry
(Tove A. Larsen, Judit Lienert, Bernhard Truffer)
In the 1990s, Novaquatis participated in the development by
­Roediger (www.roevac.com) of a new NoMix toilet permitting
the collection of undiluted urine. This appliance was used in
Final Report of the Transdisciplinary Project Novaquatis
Nova 2-2: Precipitation
(Kai Udert, Tove A. Larsen, Willi Gujer)
Nova 2-2 consisted of a doctoral thesis investigating precipitation in toilets and in waterfree and conventional urinals with the
Nova 2 – Sanitary technology
Making scents: A deodorant block that absorbs ammonia can be used as a
freshener (Photo Ruedi Keller)
Unwelcome deposits: Pipes can be blocked by urine scale (Photo Kai Udert)
aid of field measurements, laboratory experiments and computer
simulations [2–6]. Precipitates accumulating in pipes and siphons
can lead to blockages after only a few thousand uses.
When urea from urine is degraded (hydrolysed) by bacteria,
the pH rises sharply, up to 9 or more. As a result of shifts in the
buffer systems, the solubility product of various poorly soluble
salts is exceeded, leading to crystallization. This is true in particular of struvite (magnesium ammonium phosphate, MAP) and
various calcium phosphates.
Ureolytic bacteria mainly grow in the pipes and are flushed into
the collection tank. After only a few days, the urea is completely
degraded. In undiluted urine, hydrolysis of only 8 % of the urea is
sufficient to increase the pH to almost the maximum value, with
95 % of the possible precipitation being attained as a result.
Following the initially favourable experience with waterfree
urinals, it was long believed that no salts would crystallize from
undiluted urine. However, field measurements indicated that the
opposite is the case – i. e. blockages occur mainly when the urine
is only slightly diluted or completely undiluted. Calculations based
on computer modelling showed that less precipitation of salts per
volume ­ occurs with diluted than with undiluted urine. The least
precipitation occurs when rain water is used for flushing, as this
avoids the addition of either calcium or magnesium. Although the
quantity of precipitates is one of the main factors giving rise to
blockages, it is not the only one. Also critical are narrow diameters
and prolonged residence of urine in pipes and siphons.
lets available today, however, the problems need to be solved
pragmatically or alleviated, e. g. by rainwater flushing systems (cf.
“Practical guide”).
The sanitary industry is in principle interested in bringing
good-quality NoMix toilets to the market and is convinced that
this goal is achievable. However, as they are more expensive than
conventional toilets, wastewater professionals, for their part, need
to identify sizeable markets that would make it worthwhile for the
industry to become involved and to undertake costly development
work (cf. Nova 7).
The combined results from Nova 2 provide a number of indications
as to what could be done to bring an improved NoMix toilet to
the market, and what fundamental changes would be required.
Although urine dilution reduces blockage-related problems, it
entails the use of larger urine tanks. In addition, it complicates
urine treatment. A better solution might therefore be the deliberate promotion of unavoidable precipitation in undiluted urine – in
a replaceable unit in the toilet. This principle is already applied
by the industry in various waterfree urinals. For the NoMix toi-
Final Report of the Transdisciplinary Project Novaquatis
Urine on tap: Collection tank at Eawag (Photo Ruedi Keller)
Work package Nova 3
Storage and
Research background
Nova 3 is concerned with the transport of urine from the NoMix
toilet and a local tank to a central treatment plant. Various
options exist for transporting locally stored urine – tankers, separate pipes, or the existing sewer system. The latter could be used
at a relatively low cost, for example, by transporting urine at night
– i. e. at a time when in many catchments only small amounts of
water, largely unpolluted, flow through the sewers [1, 2]. However, this strategy involves certain risks, as it would entail the passage of highly concentrated urine through the sewer system for
a short time. Thus, in the event of unforeseen excessive rainfall,
large quantities of urine could enter receiving waters untreated.
In addition, odour nuisances could arise. As a transition scenario,
therefore, Novaquatis investigated another option for transporting
urine through the sewer network: the nitrogen load is distributed
over 24 hours, leading to improved utilization of capacity at an
existing wastewater treatment plant (Nova 3-1). This strategy
would make it possible to gain experience concerning the reliability of rain forecasts without running any major risks, since at
no time would the amounts of urine passing through the sewers
be larger than at present.
An alternative to the difficulties of urine transport would be
local treatment, based on the results obtained in Nova 4.
If household urine was stored and then released in a controlled
manner throughout the night, treatment plants would be exposed
to more evenly distributed nitrogen loads. In addition, it would
be beneficial to retain stored urine during periods of heavy rain,
as in such cases – at present – some wastewater is discharged
untreated into receiving waters via combined sewer overflows.
Nova 3-1 elaborated a virtual case study based on stochastic modelling. Using data from the Zurich region, it assumes a
complete changeover to NoMix toilets. According to this study, a
10-litre storage tank integrated into each NoMix toilet and a simple
control strategy would yield the following results: firstly, a reduction of more than 50 % in the annual volume of urine released by
combined sewer overflows and, secondly, a decrease of approx.
30 % in the peak load of nitrogen under dry-weather flow conditions. The first of these may be an economically attractive option,
as it reduces inputs of toxic ammonia to surface waters during
rainfall [4]. The second leads to an increase in the performance of
a nitrifying wastewater treatment plant commensurate with the
reduction in peak load. In certain cases, the (costly) expansion of
existing treatment facilities could thus be effectively avoided or
deferred ([5]; see also Nova 3-3 and 7-2).
Nova 3-2: Storage and transport
Nova 3-1: Urine source
separation and “waste design“
(Wolfgang Rauch, Willi Gujer, Tove A. Larsen)
The concept of “waste design” involves retaining portions of
the domestic or industrial wastewater that arises and only transporting it when capacity is available for the processing of these
streams at a wastewater treatment plant [3]. This system is particularly appropriate in the case of urine: because most people
use the toilet when they get up, a “morning peak” of urinary
nitrogen is recorded at wastewater treatment plants. To allow this
peak load to be processed, treatment plants currently have to be
designed with significantly larger dimensions than would actually
be required – with a corresponding increase in construction costs.
Final Report of the Transdisciplinary Project Novaquatis
(Luca Rossi, Judit Lienert, Tove A. Larsen)
An extensive series of measurements provided information on the
functioning of the NoMix technology under real-life conditions [6].
The findings of this research are important as they indicate the
need for urine to be correctly collected in the NoMix toilets and
drained into the storage tank. Household measurements revealed
that the urine yield was only 60–75 % of the amount expected,
thus showing where practical improvements to the NoMix toilets
are possible. In the institutional setting, e. g. at Eawag, consider­
ably more urine was collected with the NoMix toilets. However,
the potential for improvement can only be estimated for the
­women’s toilets, since the men use the urinals in most cases.
Further measurements indicated that in 55–60 % of flushes, the
low water volume button was pressed. In certain households,
Nova 3 – Storage and transport
Gone but not forgotten: The date and time of each flush are recorded by a
digital counter at Eawag (Photo Ruedi Keller)
Community-level toilet usage: Precise data on housing, employment and
recreation are required for the microsimulation model (Photo Karin Güdel)
however, the low-flush option was hardly ever used; in the institu­
tional setting, the proportions varied widely. The frequency of
flushing in households clearly demonstrated the reason for the
“morning peak” in nitrogen levels at wastewater treatment plants:
not only is morning urine more concentrated, but flushing is more
frequent at this time of day. In addition, marked differences were
observed for households between weekdays and the weekend.
This coincides precisely with the results of measurements at
wastewater treatment plants. The detailed data can be used to
help design urine storage tanks for future pilot projects, thereby
avoiding the construction of units that are too large – and costly
– or too small.
Nova 3-3: Microsimulation model (formerly Nova 7-1)
(Christian Spörri, Peter Reichert, Irene Peters, Tove A. Larsen)
A new computer model based on microsimulation was used to
evaluate the effects of different strategies for the management of
urine tanks [7]. The test region was the catchment of the Ergolz
1 wastewater treatment plant in the canton of Basel-Landschaft.
The model is based on census data concerning residents, their
workplaces and residential and commercial buildings. It represents
people’s movements to work, recreational activities and service
enterprises. Medical data provided the basis for simulating people’s urination patterns and, hence, urine production in individual
toilets. Rain forecasts and precipitation data from the region were
used to identify optimum tank management strategies, with the
aim of achieving the goals defined in Nova 3-1 – levelling out
nitrogen loads at the wastewater treatment plant and avoiding
urine releases from combined sewer overflows. With a random
distribution of NoMix toilets in only 30 % of the apartments and
workplaces and a tank capacity of 10 litres, the model generates
the following predictions: the peak load entering the wastewater
treatment plant is reduced by 20 %, and at the same time urine
concentrations in the sewer system during rainfall are lowered by
22 %. More elaborate modelling thus makes it possible to identify
better control strategies than the one applied in Nova 3-1, which
assumes universal distribution of NoMix toilets.
The key problem for the NoMix technology is how to transport
urine from the NoMix toilet to a central treatment plant. Nova 3
shows that a good interim solution can at least be found for urine
transport, which optimizes the capacity of wastewater treatment
plants – i. e. transport via the existing sewer system, with urine
streams distributed over 24 hours. In principle, it would also be
possible to discharge concentrated urine through the sewer network in a wave. However, the feasibility of this approach would
have to be demonstrated by experience from a large-scale practical
project. Implementation of the interim solution would permit such
experiments. As an alternative to the difficulties of transport,
urine could be treated locally in accordance with the findings of
Nova 4.
Practical experience from the pilot projects shows that there is
room for improvement in the efficiency of urine source separation
in NoMix toilets – a finding that is of particular relevance for the
further development of the NoMix appliances.
Final Report of the Transdisciplinary Project Novaquatis
Biological reactor for stabilization (Photo Yvonne Lehnhard)
Work package Nova 4
Research background
The bulk of the nutrients from human metabolism are excreted in
urine – in particular, nitrogen (N), phosphorus (P) and potassium
(K). These nutrients are desirable in agriculture, but not in waterbodies (where only K causes no harm). It may therefore make
sense to separate urine from wastewater and use it for fertilizer
Fresh urine is slightly acidic, with a pH of 6–7. However, the
high concentration of biologically degradable substrate promotes
rapid bacterial growth. As a result, the chemical composition of
urine undergoes significant changes during collection and storage.
Since urea is hydrolysed to ammonia and carbon dioxide, the pH
rises sharply – to more than 9 (cf. Nova 2). In addition, urine contains organic micropollutants, especially pharmaceutical residues
and hormones, which are equally unwelcome in waterbodies and
in agriculture (Nova 5).
The various treatment processes serve widely differing purposes: urine can be stabilized and its volume reduced; nitrogen
and phosphorus can be recovered or removed; and bacteria,
­viruses and micropollutants can be eliminated [1]. However, it is
not possible to achieve all the different objectives using a single
process; a decision is thus required as to what is desirable and
what is necessary.
In general, urine treatment may involve biological (Nova 4 -1),
chemical (Nova 4-2, 4-3) or physical (Nova 4-3) processes. The
­advantages and disadvantages of the various methods are discussed in detail in [1].
Nova 4-1: Biological processes – stabilization
(Kai Udert, Tove A. Larsen, Willi Gujer)
Nova 4-1 was concerned with the development of a biological
process for urine stabilization [2]. Bacteria cultured in a reactor
not only decompose organic compounds in urine but also convert
a portion of the ammonium to nitrite or nitrate (nitrification). This
leads to the production of acid, which lowers the pH of the urine
from more than 9 to about 6, preventing losses of ammonia. At the
same time, the biological processes eliminate unpleasant odours.
Final Report of the Transdisciplinary Project Novaquatis
With this process, a solution of ammonium nitrate or
ammonium nitrite is obtained. The nitrogen compound ammonium
nitrate is a commercial fertilizer. Ammonium nitrite, in contrast, is
toxic to soil organisms. However, it can readily be converted to
nitrate through chemical oxidation with oxygen at a low pH value
[3] or, using another biological process, to a harmless nitrogen gas
and water [2].
Nova 4-2: Chemical processes –
phosphorus precipitation
(Mariska Ronteltap, Max Maurer, Willi Gujer)
The chemical conditions in stored urine (i. e. high pH values) promote the precipitation of phosphorus in the form of poorly soluble
phosphorus-containing salts. This leads to encrustation and clogging of pipes (Nova 2). However, the process can also be used for
phosphorus recovery.
With controlled addition of magnesium, phosphorus can
be recovered in the form of struvite (MgNH 4PO 4, magnesium
ammonium phosphate, MAP). This is attractive, as two significant
wastewater nutrients (P and N) are thus transformed into a single
solid product, which is, moreover, a well-established slow-acting
multicomponent fertilizer.
Nova 4-2 investigated in detail the process whereby struvite
is produced from urine [4]. It was shown that the rate of phosphorus elimination depends crucially on the degree of dilution,
but generally reaches 98 %. The product obtained is largely free
of pharmaceuticals and hormones, and no heavy metals could be
detected [5].
Although struvite can be used directly as a fertilizer, it is not
suitable for further processing in the phosphorus industry [1]. In
a Novaquatis follow-up project, other precipitation products are
being studied that would be suitable for further processing of this
kind. Thus, both options can be kept open.
Nova 4 – Process engineering Murky mixture: Magnesium-chloride is
added to urine (Photo Yvonne Lehnhard)
Clean product: A pure nutrient powder is obtained (urine-based
fertilizer struvite) (Photo Mariska Ronteltap)
Clean bill of health: Analysis of micropollutants (Photo Yvonne Lehnhard)
Nova 4-3: Physical processes – membrane technology
(Wouter Pronk, Markus Boller)
Nova 4-3 considered various urine treatment scenarios, focusing
on membrane technologies. The aims of these methods are threefold: (1) to separate organic micropollutants from nutrients, (2) to
concentrate the nutrient solution (volume reduction) and (3) to
remove or destroy bacteria and viruses. In addition, micropollutants can also be eliminated via the chemical process of ozonation.
The membrane technology of nanofiltration was tested in the
laboratory. The process is only effective if urea in fresh urine is not
hydrolysed. If this can also be successfully prevented in practice
– e. g. through acidification – nanofiltration can be used to produce a urea solution (without phosphorus). This solution is largely
unproblematic: a large proportion of the organic micropollutants
can be separated from the nutrients, and bacteria and viruses
are eliminated [6]. In the nanofiltration process, the nutrients are
not concentrated – in a further project, vacuum evaporation was
employed for this purpose. With this process, the volume of a
urea solution was reduced by 90 % at 78 °C [1].
Also tested in the laboratory were the membrane-based process of electrodialysis and the chemical process of ozonation. With
the aid of electrodialysis, micropollutants can be largely separated
from ammonium, phosphorus and potassium, as can microorganisms such as bacteria. At the same time, the nutrient solution
is concentrated roughly fourfold [7]. If ozonation is additionally
performed, the fertilizer produced is highly likely to be acceptable
as regards both hygiene and contamination with pharmaceuticals
and hormones.
In a follow-up project, electrodialysis and ozonation are
being tested on a pilot scale for the treatment of urine collected at
the Basel-Landschaft cantonal library in Liestal [8] (cf. Nova PP).
The nutrient solution produced here contains 12 g N, 0.65 g P and
5.7 g K per litre.
The wide variety of urine treatment processes available offers
substantial flexibility. For example, if a rural setting calls only for
stabilization, to prevent the release of ammonia when fertilizer is
applied, a one-step biological treatment should be sufficient. But
if nutrients are to be recycled in a metropolis – as would be advisable in areas with a general lack of fertilizers – the demands are
higher, and various processes will need to be combined. Nutrients
can, however, also be eliminated – e. g. to protect sensitive receiving waters from excessive nutrient loads.
All the processes will require further development before they
can be implemented in practice. But thanks to the Nova 4 research,
we now know precisely what processes are currently available, for
what purposes they are suitable, and in what respects they need
to be optimized.
In many cases, separate removal or recycling of nutrients is
preferable to the existing practice. This also applies to the energy
requirements associated with these processes [1, 9].
Final Report of the Transdisciplinary Project Novaquatis
Painkillers end up in waterbodies (Photo Yvonne Lehnhard)
Work package Nova 5
Research background
Medicines and hormones can be detected in wastewater treatment plant effluents, in surface waters and in groundwater – i. e.
they are only partly removed by wastewater treatment processes.
This may be problematic; for example, reproduction in fish is influenced by the highly bioactive hormones. Although the severity of
the problem remains unclear, caution is required given the sheer
variety of substances in use – in 2005, 4727 human medicines
were registered in Switzerland.
Many substances ingested by humans are transformed in the
body (metabolized) and excreted in the urine or faeces. This is
a drawback if fertilizer is produced from urine, since micropollutants are also undesirable in agriculture (Nova 6). Accordingly,
the removal of such substances was one of the aims of the treatment processes studied in Nova 4. In Nova 5, ecotoxicological and
chemical analytical methods were developed in order to evaluate
the quality of the urine product. Urine source separation would be
beneficial in terms of water pollution control, as the substances
contained in urine would thus be prevented from entering wastewater streams.
Nova 5-1: Ecotoxicological tests
for urine quality control
(Beate Escher, Rik Eggen, Nadine Bramaz)
In Nova 5-1, a test battery was developed with the aim of determining in vitro whether pharmaceuticals in urine pose an environmental risk (ecotoxicological hazard) [1, 2]. The battery includes
non-specific tests, showing a reaction to general cell damage
[3]. In addition, specific tests indicate, for example, whether a
sample contains substances that are hormonally active, attack
genetic material or disrupt plant photosynthesis [4]. Thus, rather
than measuring a single drug and its metabolites, tests of this kind
determine the overall effect. To rule out interference from natural
urine components (e. g. salts, high pH), a solid-phase extraction
method was developed for the preparation of samples [1].
The test battery permits effective quality control of the treatment processes with regard to the removal of micropollutants
Final Report of the Transdisciplinary Project Novaquatis
(Nova 4). For example, while the efficiency of the bioreactor was
found to be inadequate [5], struvite precipitation was shown to
be highly efficient: the micropollutants studied were almost completely removed. Nanofiltration removed 50–90 % of the toxicity,
and ozonation – depending on the ozone dose – 55–99 %. It was
concluded that the effects of the treatment processes varied
widely, and the results of the various bioassays were sharply divergent. The methods tested thus remove different substances to
different extents.
Nova 5-2: Measuring hormones in urine
by chemical analysis
(Marc Suter, René Schönenberger)
In the EU COMPREHEND programme, analytical tools were
developed for the detection of endocrine-disrupting substances
in effluents from wastewater treatment plants across Europe
[6]. In Nova 5-2, one of these new chemical analytical methods
(liquid chromatography/ mass spectrometry/ mass spectrometry;
LC / MS / MS) was adapted so as to permit measurement of hormones in urine. Urine in the reactors from Nova 4 was spiked with
known quantities of the natural female hormone estradiol and the
synthetic ethinylestradiol (active substance in oral contraceptives)
[5]. Can these hormones be eliminated? Electrodialysis removed
98 % of the estrogens. However, as a large proportion is retained
by the membranes, these have to be cleaned in a separate step.
After 24 hours, the bioreactor had removed 89 % of the natural
estradiol, but only 55 % of the synthetic hormone used in contraceptives. Hormones were no longer detectable in struvite, and
estrogenic activity was also eliminated with ozonation.
Nova 5-3: Measuring pharmaceuticals in urine
by chemical analysis
(Alfredo Alder, Christa McArdell, Elvira Keller)
The EU Poseidon project (http://poseidon.bafg.de/) studied
technologies for the removal of pharmaceuticals at wastewater
treatment plants. In Nova 5-3, the chemical methods developed
Nova 5 – Micropollutants Test battery: The hand is holding the algal
assay (Photo Yvonne Lehnhard)
True colours: Reddish colour changes of the YES test indicate the
presence of estrogens (Photo Yvonne Lehnhard)
in the Poseidon project for wastewater were to be adapted for
the analysis of urine. However, control measurements indicated
that this approach was unsuitable for this purpose. Using other
methods from Nova 4-3, however, it was possible to measure
individual substances [5].
High tech in the lab: Samples are loaded
for chromatography (Photo Y. Lehnhard)
analgesic drugs, poses a relatively high risk to the environment.
Considerable differences were found in the site of activity: some
substances developed their toxic potential mainly in the urine,
­others in the faeces. While the screening method has its limitations, we estimate on the basis of the limited data known to us
that the ecotoxicological hazard potential associated with pharmaceuticals in urine and faeces is of about the same magnitude.
Nova 5-4: Contribution of urine source separation
to water pollution control
(Judit Lienert, Beate Escher, Karin Güdel, Timur Bürki)
Nova 5-4, which was co-financed by the Federal Office for the
Environment (FOEN; www.bafu.admin.ch), investigated whether
urine source separation can contribute to water pollution control.
The differences observed between 212 active ingredients (corresponding to 1409 pharmaceutical products) were immense.
For example, urinary excretion of X-ray contrast agents was
90–100 %, compared with only 6 % for one cancer drug and 98 %
for another. On average, 64 % of the active ingredient ingested
was excreted in the urine. Also on average, 42 % was transformed
in the body and excreted as metabolites, which were mainly found
in the urine [7].
Using a screening method, it was possible to assess the
environmental hazard posed by excreted pharmaceuticals. The
method is based on literature data, e. g. on the chemical properties and metabolism of the active ingredient, and on the quantities
of medicines sold. It was developed with reference to drugs used
in cardiology (beta-blockers). In the case of these agents, the
Nova 5-1 test battery revealed an unexpected effect: they inhibit
the photosynthesis of algae [4]. The method was subsequently
­applied to the (avian) influenza drug tamiflu, which is metabolized
to 75 % in the human body (data not published). For tamiflu, the
ecotoxicological hazard estimated with the screening method
would appear to be low.
Another 42 substances were then investigated [8]. In 34 cases,
the toxic potential was reduced by metabolism in the human body.
The ecotoxicological hazard of each of these substances after
being metabolized tended to be low. However, there were some
exceptions: ibuprofen, in particular, which is found in numerous
It was demonstrated by chemical and ecotoxicological analysis
that pharmaceuticals and hormones can be removed from urine
with the aid of treatment processes studied in Nova 4. However,
not all methods were equally effective [5]. Many pharmaceuticals occur only in trace amounts that can barely be measured by
chemical analysis. Chemical methods are valuable, for example, in
characterizing the degradation processes of individual substances.
Ecotoxicological tests are suitable for estimating the overall toxicity of natural urine samples [1, 2]. However, it needs to be borne in
mind that, in certain bioassays, effects may be produced merely
by natural urine components [5].
Urine source separation can help to protect waterbodies from
micropollutants. However, even if it were to be fully implemented,
not all pharmaceuticals and hormones would be prevented from
entering wastewater [7]. On the basis of estimations and limited
data, we assume that urine source separation would remove about
half of the ecotoxicological hazard potential [8].
Final Report of the Transdisciplinary Project Novaquatis
Pot plant: Ryegrass (Photo Jürgen Simons)
Work package Nova 6
Research background
In Switzerland, nutrients from human urine could supply around
37 % of the nitrogen, 20 % of the phosphorus and 15 % of the
potassium demand currently met by artificial mineral fertilizers
[1]. The original aim of Nova 6 was to study the possibilities and
problems of this type of urine recycling. Unfortunately, funding
could not be secured for these research projects. However, with
the aid of external partners, two key questions were investigated:
Would a urine-based fertilizer be well received by farmers and the
public? And is treated urine as effective as artificial fertilizers?
Nova 6-1: Is urine-based fertilizer found acceptable?
(Judit Lienert, Michel Haller, Alfred Berner, Michael Stauffacher,
Tove A. Larsen)
In 2000, 467 questionnaires were sent to Swiss farmers, with four
categories being distinguished: organic or integrated (IP) farming, and with or without vegetable production [1]. The response
rates for the individual groups varied and were low overall (127
responses received). Although the results are thus not representative, they do provide important initial evidence.
Urine-based fertilizers were favourably viewed by 57 % of respondents, and 42 % would purchase such products – especially
those who already buy additional fertilizers. As this mainly applies
to IP and vegetable farming, these would probably be the most
promising markets. However, no farmers would be prepared to
pay a higher price than for conventional fertilizers. Most prefer
a nitrogen fertilizer in the form of ammonium nitrate. In addition,
a granulate is preferred to a liquid formulation, and a urine odour
is rejected. A key requirement is that the urine-based fertilizer
should be hazard-free, with 30 % expressing concerns that it could
contain micropollutants, e. g. pharmaceutical residues.
Consumers’ attitudes appear to be similarly favourable (Nova
1). However, this group would likewise only buy food grown with
urine-based fertilizers if it was hazard-free. High priority is therefore given to the elimination of pathogens and medicines from
urine – for example, among the participants of a focus group study
(Nova 1, [2]). Of 501 people surveyed at the BL cantonal library
Final Report of the Transdisciplinary Project Novaquatis
(Nova PP), two thirds would also use a urine-based fertilizer in
their own garden or buy vegetables to which it had been applied
(results not yet published). The other third was opposed to urinebased fertilizers on the grounds of distaste or health concerns.
Nova 6-2: Pot experiments with
urine-based fertilizers
(Jürgen Simons, Joachim Clemens)
In a Bonn University dissertation project, the suitability of Nova 4
urine products as fertilizers was assessed in greenhouse experiments [3, 4]. Ryegrass (Lolium multiflorum italicum) and red clover
(Trifolium pratense) were used as test plants. The study compared
seven different nitrogen-enriched substrates – including untreated
urine and the products of Nova 4-1 (bioreactor) and Nova 4-3
(nanofiltration, electrodialysis) – with an artificial fertilizer (calcium
ammonium nitrate). In addition, five phosphorus fertilizers, including struvite (MAP; Nova 4-2), were compared with the artificial
fertilizer superphosphate.
Plants treated with urine-derived nitrogen showed practically
the same yield as those receiving the mineral fertilizer, with the
same uptake of nitrogen from the soil. Differences between the
products tested can be explained by differences in pH and the
resultant ammonia losses. Thus, plants fertilized with acidified
urine (pH 4) showed a significantly higher yield than those receiving untreated urine (pH 9).
The phosphorus fertilizers tested differed from the artificial
fertilizer – both in yield and in phosphate uptake. Phosphates
precipitated with magnesium, including the struvite from Eawag
(MAP), produced comparable values to the artificial fertilizer. In
contrast, phosphate fertilizers from sewage sludge – precipitated
with iron, for example – produced significantly poorer results. In
general, the struvites from decentralized wastewater treatment
were more homogeneous than those from the wastewater treatment plant – with regard to composition and fertilizer efficiency.
As the differences cannot be fully explained, further research is
required, e. g. to analyse and optimize the production processes.
Nova 6 – Agriculture
The right dose of fertilizer: ”Urevit” is carefully
measured out (Photo Martin Koller)
Slurry versus urine: Treatment of maize plants in
a field test (Photo Martin Koller)
Smart vegetables: Many consumers accept a
urine fertilizer (Photo Yvonne Lehnhard)
Nova 6-3: Field tests with urine-based fertilizers
(Martin Koller, Alfred Berner, Wouter Pronk, Steffen Zuleeg,
Markus Boller, Judit Lienert)
Following electrodialysis and ozonation treatment, urine from
the BL cantonal library is to be used as a fertilizer (Nova PP). In
2006, the Research Institute of Organic Agriculture (FiBL; www.
fibl.org) was therefore commissioned by Novaquatis to study the
urine’s fertilizer properties. The tests were carried out at an IP
site – using fodder maize, which has a high nitrogen requirement.
Here, the urine-based fertilizer “Urevit” was compared with cattle
slurry, “Kompogas” anaerobic digester liquid, commercial organic
fertilizer (feathermeal) and synthetic fertilizer (ammonium nitrate).
“Urevit” is more stable than untreated urine, the nutrient content
is about three times higher, and the product is – as far as is measurable – free of bacteria, viruses and micropollutants.
The key finding is that “Urevit” is suitable for use as a fertilizer.
After the main growth period, maize treated with “Urevit” showed
the same height and leaf colour as that treated with a mineral
fertilizer; both groups were superior to the plants treated with
cattle slurry or feathermeal. Since leaf colour in maize is closely
correlated with nitrogen supply, “Urevit” and mineral fertilizer
initially act equally rapidly. However, the “Urevit”-treated plants
– like those receiving “Kompogas” or feathermeal – had a significantly (15 %) lower yield than maize treated with mineral fertilizer.
Nitrogen was presumably lost when “Urevit” was applied, but
such losses could be controlled by optimizing urine processing
and spreading. Today, fertilizers are often applied using trailing
hoses. If “Urevit” was distributed to farmers free of charge, the
costs of this spreading method would be roughly the same as for
ammonium nitrate – making “Urevit” an economically attractive
option for farmers.
The Basel-Landschaft utilities agency (AIB; cf. Nova PP)
received provisional approval from the Federal Office for Agriculture (FOAG; www.blw.admin.ch) to use “Urevit” as a fertilizer –
definitive approval can only be granted when stringent quality
requirements are met. As an interim step, the fertilizer could be
used for non-agricultural purposes, e. g. for ornamental plants at
local horticultural firms.
In the course of Nova 6, important contacts were established with
agricultural partners, e. g. the FOAG (Nova 6-3), FiBL (Nova 6-1,
6-3) and Agroscope Reckenholz-Tänikon Research Station (ART;
www.art.admin.ch). Representatives of this sector approve of the
cautious approach adopted by Novaquatis; in this way, polemical
debates – of the kind that led to the ban on the use of sewage sludge
in Swiss agriculture – can be avoided. Farmers and consumers
(Nova 6-1) are sympathetic to the idea of urine-based fertilizers.
However, both groups emphasize that it is essential to eliminate
any risks – e. g. posed by micropollutants. Such substances need
to be effectively removed (Nova 4). But since absolute safety can
never be attained, ecotoxicological studies (Nova 5) in subsequent
projects should be accompanied by a broader social debate – also
involving agricultural representatives, consumer groups and the
major food retailers.
Thanks to Nova 6, we now know how farmers and the public
can be expected to react, and what steps should be taken in introducing a urine-based fertilizer on the Swiss market. We also
know that urine-based products are suitable for use as fertilizers
and are generally comparable to artificial fertilizers. Still, fertilizers
are currently very inexpensive – at least in industrialized countries. The question therefore arises to what extent costly fertilizer
production processes, as implemented on an experimental scale
in Novaquatis, would be worthwhile. In the numerous parts of
the world (e. g. Africa, China) where nutrients are in short supply,
however, the case for using urine as a fertilizer is compelling.
Final Report of the Transdisciplinary Project Novaquatis
Stakeholders discuss the NoMix technology (Photo Karin Güdel)
Work package Nova 7
Research background
Nova 7 is concerned with evaluating the advantages and disadvantages of the NoMix technology. Technology assessments are
always difficult – especially when the technologies in question do
not yet exist. For example, how are we to determine overall costs
or energy consumption merely on the basis of prototypes in the
laboratory? And how can we give due consideration to all the various aspects? Nova 7-1 summarizes the main results of Novaquatis
obtained in the course of the entire project. Nova 7-2 tests a
methodological approach comparing various NoMix options with a
conventional solution for a specific scenario. The different options
are based on the preferences of actual stakeholders.
Nova 7-1: Evaluation of the NoMix technology
(Tove A. Larsen, Max Maurer, Kai Udert, Judit Lienert)
The NoMix technology makes it possible for nutrients to be comprehensively eliminated or recycled through a relatively minor
modification to the wastewater system [1]. However, whether
– and in what form – it is worth implementing the technology
depends largely on the existing infrastructure and environmental
situation. The NoMix technology is particularly valuable where
nutrient emissions are subject to stringent regulations. It is also to
be recommended in regions where it makes economic sense to
recycle nutrients to agriculture.
The importance of the NoMix technology is assessed on a
broad scientific basis in [2]. In global cycles, nutrients from human
metabolism do not play a significant role. The nitrogen cycle is
dominated by biological and industrial nitrogen fixation. Human
excretion only accounts for about 5 % of the total production of
reactive nitrogen. In the global phosphorus cycle, agriculture is
probably the dominant factor. With regard to water resources, by
contrast, phosphorus and nitrogen inputs from wastewater are of
major importance. It is therefore worth looking for efficient ways
of removing these nutrients – especially in densely populated
areas where wastewater constitutes the largest proportion of
nutrient flows or where conventional technology is overstretched.
In Switzerland, one example would be Lake Greifen, where the
Final Report of the Transdisciplinary Project Novaquatis
quality targets specified for phosphorus cannot be complied with.
Internationally, a good example is the Chinese city of Kunming (cf.
Nova 8). Globally, nutrients from wastewater will play an increasingly important role as a result of population growth. In Europe,
too, a trend towards stricter nutrient emission limits is discernible. Urine source separation would also be beneficial for water
pollution control, as the ecotoxicological hazard posed by human
medicines could be reduced by an estimated 50 % (cf. Nova 5).
In countries with chronic shortages of nutrients for agriculture,
wastewater represents a local resource. The nutrients which it
contains can best be recovered by at-source measures.
The NoMix technology can turn a wastewater treatment plant
from an energy consumer into an energy producer: instead of
11 watt per person being consumed, 2 watt of primary energy
per person can be generated, as the energy efficiency of many
processes is increased and the energy in wastewater can be
better exploited [3]. Thus, the wastewater management sector
could contribute to the attainment of the “2000-watt society”,
the Federal Council’s aspiration target of reducing Switzerland’s
primary energy consumption from 6000 watt to 2000 watt per
person. Energy savings could also be realized in fertilizer production, with energy-efficient processing of nitrogen and phosphorus
for the agricultural sector [4]. In view of the deteriorating quality
of artificial phosphate fertilizers – remaining mineral resources of
phosphorus have a high heavy-metal content – it would be worthwhile to recycle relatively pure phosphorus from urine [2]. In the
case of nitrogen, the key considerations concern energy and the
quality of the fertilizer produced.
As the NoMix technology offers numerous environmental
advantages, the decision for or against its adoption is largely influenced by human factors: Is the technology acceptable (Nova 1)?
And can it be implemented at low cost, or at least without
increasing costs? The costs of the NoMix technology cannot yet
be comprehensively estimated. But, according to calculations
given in [5], investments of around CHF 1250–2100 per household in this technology would not increase current overall costs in
Switzerland. This would, however, require a well-planned system
transition, as the additional investments in the NoMix technology
Nova 7 – Evaluation
Large sewers and treatment plants to cope with the flood of wastewater:
Maybe there’s an alternative? (Photo Christian Abegglen)
Potential in every bathroom: Should new housing developments be fitted
with the NoMix technology? (Photo Andri Bryner)
would have to be financed by reduced investments in wastewater
treatment plants. An increase in the total operating costs of the
two systems would have to be excluded.
sensitivity analysis also shows that, if greater weight is assigned
to environmental questions, the NoMix option rapidly becomes
­attractive even at a higher price. There are indications, for examle,
that the new environmental issue of “micropollutants” could shift
priorities in favour of this option.
Nova 7-2: Structuring of the NoMix
decision-making process
(Mark Borsuk, Max Maurer, Judit Lienert, Tove A. Larsen)
Nova 7-2 is primarily a methodological project, designed to com­
pare various NoMix technology options in a specific scenario
[6]. It is based on a decision analysis considering a wide variety
of criteria. This was applied to the Glattpark site (lying north of
­Zurich), which is currently being developed. Wastewater from
this development is to be treated at the Kloten / Opfikon plant,
which is already operating at full capacity. This gave rise to the
hypothesis that application of the NoMix technology would allow
a costly expansion of the treatment plant to be avoided or at least
Initially, the objectives of the five major stakeholder groups
were defined. It was then assessed how far each of the various
options fulfilled the different stakeholders’ objectives. The main
options studied were: (A) NoMix toilets only in the Glattpark development, to level out nitrogen loads at the treatment plant (Nova
3-1); (B) NoMix toilets installed throughout the catchment, with
separate treatment of urine; (C) expansion of the treatment plant,
without urine source separation. Finally, a ranking of options (from
most to least preferred) was prepared for each group of stakeholders. In addition, a sensitivity analysis was performed to investigate
the significance of uncertain assumptions for the scenario.
The results show that no single option is equally attractive to all
stakeholders. The local authority could make considerable ­savings
if urine was separately collected and treated across the entire
catchment. Households, however, will only accept the NoMix
technology if a very comfortable NoMix toilet is available and the
higher costs are subsidized by the local authority. But for the costs
of the NoMix toilet to be sufficiently reduced, mass production
would be required – and this is not possible within the planning
period envisaged for the Glattpark development. However, the
The NoMix technology is attractive because it has the potential,
through a minor intervention, to contribute to environmental protection in an energy-efficient way. Both globally and in Europe,
the technology offers advantages over the current situation;
waterbodies, in particular, will benefit, as nutrient inputs from
wastewater can be substantially reduced. Regions where acute
population pressures lead to severe eutrophication of waterbodies
would be the areas of choice for initial implementation. In addition, the NoMix technology can provide a valuable local source
of fertilizers where nutrients for agriculture are in short supply.
Combined with conventional end-of-pipe (sewer and treatment
plant) techno­logy for the remaining wastewater, the NoMix concept could well become economically competitive in Europe too,
given that, for example, up to CHF 2000 or more would be available for each Swiss household for investments in this technology.
The challenge for research, in collaboration with industry, is now
to develop the appropriate NoMix technology at this price.
Final Report of the Transdisciplinary Project Novaquatis
Stakeholders discuss NoMix toilets (Photo Edi Medilanski)
Work package Nova 8
Research background
Nova 8 was concerned with the introduction of the NoMix technology in fast-industrialising countries, where conventional end-ofpipe approaches to wastewater treatment are generally preferred
at present. Source control measures such as urine separation
could offer a good alternative – not least because of the acute
demographic pressures faced by these countries and their often
limited financial and scarce freshwater resources. In cases where
no sewerage system is yet in place, fast-industrialising countries
have greater scope for planning than typical European nations.
Kunming, the capital of Yunnan Province in South-West
China and sister city of Zurich, was selected as the pilot region
for Nova 8. With a population of about 2.4 million, the city lies on
Lake Dianchi, a shallow waterbody with excessive phosphorus
levels. By 2020, the number of inhabitants is expected to have
grown to 4.5 million. Although six modern wastewater treatment
plants have been built in recent decades, water quality in Lake
Dianchi has not improved.
The projects were financed by the Swiss National Science
Foundation (SNF; www.snf.ch) and the Swiss Agency for Develop­
ment and Cooperation (SDC; www.deza.admin.ch) and carried
out under the Swiss National Centre of Competence in Research
North-South programme (NCCR North-South; www.nccr-northsouth.unibe.ch). The work received strong support from stakeholders in Kunming – an indispensable aid in gaining access to
data and other information.
Nova 8-1 Material flow analysis of wastewater
(Dong-Bin Huang, Hans-Peter Bader, Willi Gujer, Ruth Scheidegger,
Roland Schertenleib)
In a doctoral thesis, a methodology was developed for material
flow analysis of wastewater – including constituents and pollutants – in fast-industrialising countries, tailored to the particular
requirements of such regions. The key factors to be considered
are the scarcity of data and rapid urban development. In the study,
various strategies for wastewater treatment were evaluated on
Final Report of the Transdisciplinary Project Novaquatis
the basis of material flow analysis, including a number of source
control measures [1].
As a case study, the wastewater system in Kunming was
modelled. The most important finding was that only about 25 % of
all urban wastewater is treated at the city’s six wastewater treatment plants; the remainder is discharged into the lake untreated.
One of the main reasons is that clean water – especially ground
and river water – infiltrates the sewers, so that wastewater is
diluted in a ratio of at least 1:1. As a result, around 1600 of a total
of 1960 tonnes of phosphorus in urban wastewater enters the
lake each year. The ambitious goal set by the local authorities,
however, is to restore water quality to 1960 levels, which would
mean that only some 30 tonnes of phosphorus per year could be
discharged into the lake. This assumes, moreover, that similar
efforts are undertaken by agriculture and industry [1]. Lake Dianchi
is essentially too small and too shallow to absorb the wastewater
from such a huge city – quite apart from the fact that it is also
exposed to phosphorus inflows from other sources.
The model indicated that even with “perfect” technology – conditions approximated by the infrastructure in Zurich, for ­example
– the targets set for water quality would not be attainable: at least
56 tonnes of phosphorus per year would still be discharged into
the lake. The potential contribution of urine source separation was
also revealed by the model: if two thirds of all urine was separated
and this source control measure was combined with “ideal” wastewater treatment technology, the goal would only be narrowly
missed, with phosphorus inflows of 39 tonnes per year [1].
The real challenge now lies in finding a combination of
rational measures that is both realistic and will make it possible
to achieve the ambitious goals. Clearly, different solutions will be
required for urban as opposed to rural regions, and for older parts
of downtown Kunming as opposed to new developments where
an infrastructure has yet to be established.
Nova 8 – China
Booming city, “blooming” Lake Dianchi: Wastewater from Kunming causes
severe eutrophication, with algal blooms (Photo Edi Medilanski)
NoMix technology, made in China: The faeces are collected in a chamber
at the back, while the urine flows into a pot (Image Lin Jiang)
Nova 8-2: Introduction of urine source separation
(Edi Medilanski, Liang Chuan, Zhi Guoqiang, Hans-Joachim ­Mosler,
Roland Schertenleib, Tove Larsen)
What solutions to the problems discussed above are preferred
by local experts? The situation was first analysed on the ground
in order to gain an understanding of decision-making processes
and to identify the local actors [2]. Two-hour interviews were then
conducted with representatives of 32 different stakeholder groups,
so as to determine their attitudes to source control measures in
general and to urine source separation in particular [3].
The most important actor – together with the highest-level
­political bodies and various environmental protection and planning agencies – is the Dianchi Lake Protection Bureau [2]. This
authority plays a key role in all decisions concerning the lake. Local
experts also mentioned the important role of private real estate
companies, which have the ability to promote or reject alternative
wastewater management technologies. An important part in decision-making is also played by research institutes, which can carry
out pilot projects. As Nova 8-2 showed, successful pilot projects
may trigger large-scale initiatives (see below).
Almost all of the local experts have a favourable attitude
towards source control measures [3]. Unlike European specialists,
however, they tend to approve of such measures for concentrated
wastewater streams, such as toilet waste, rather than for “clean”
wastewater, such as rain and river water. The respondents were
well aware of the problems associated with existing technologies,
such as dry toilets. Nonetheless, an optimistic view is taken of
technological developments, and such measures are increasingly
accepted by society.
Nova 8-2 included a pilot project involving urine-diverting
dry toilets in a rural setting [4, 5]. Overall, this project was very
success­ful, prompting plans to install more than 100 000 dry
toilets in similar areas.
In fast-growing cities of fast-industrialising countries with significant population pressures and scarce freshwater resources, the
limits of end-of-pipe wastewater treatment solutions are increasingly apparent. In Kunming, urine source separation can make an
important contribution to resolving the wastewater problem. Different approaches will presumably be required for rural and urban
areas. It is clear that, faced with a population explosion, the city
of Kunming is pressing ahead with efforts to rehabilitate the lake
– an extremely challenging task. At the same time, stakeholders
in this highly dynamic city show a marked willingness to accept
innovations, and concrete measures can be quickly implemented
in rapidly expanding regions of this kind.
Final Report of the Transdisciplinary Project Novaquatis
The cantonal library BL in Liestal (Photo Steffen Zuleeg)
Work package Nova PP
Pilot projects
Every innovation has to stand the test of real-life conditions, and
technologies can only be refined with the aid of practical projects.
NoMix pilot projects are particularly challenging, as the toilets have
to be tested by users in their bathrooms before the standards of
conventional lavatories have been attained ([1]; see also “Practical
Large sanitary technology companies are reluctant to invest in
NoMix toilets while the market is still limited ([2]; Nova 2). However, a sizeable market will only arise if large-scale demonstration
projects can be carried out, which in turn pose difficulties owing
to the deficiencies of NoMix toilets – a catch-22 situation. The
only option is to conduct pilot projects – as best one can – using
today’s technology [1]. We thank all those who participated in
pilot projects for their courage in supporting the NoMix venture.
Novaquatis learnt a lot from this experience.
Pilot project I: Private apartments
(Coordination: Judit Lienert)
In 2001, four apartments in an urban housing development were
fitted with NoMix toilets by Roediger (www.roevac.com), including a tank in the basement, on the initiative of a developer motivated by environmental concerns. The project received financial
support from the federal, cantonal and municipal authorities, while
scientific management was provided by Novaquatis. The aim was
to study the attitudes of domestic users to NoMix toilets (Nova 1)
and their functioning under real-life conditions (see “Practical guide”). In addition, data were collected on urine volumes
(Nova 3). Initially, communication with the tenants proved to be
difficult, but the situation improved when a single person within
Novaquatis was responsible for all contacts. In 2003, defective
ceramics meant that two toilets had to be replaced – by conventional toilets, at the tenants’ request: one child had had problems
using the NoMix toilet, and the other household was generally
sceptical. The NoMix toilets met with the approval of the other
two households. However, in 2005 these also had to be replaced,
as a result of defective ceramics and a malfunctioning urine outlet.
Final Report of the Transdisciplinary Project Novaquatis
As this was the only pilot project involving domestic users, the
experience gained is extremely valuable for Novaquatis and the
sanitary industry (Nova 2). Our feedback to Roediger was used to
make improvements, e. g. to the ceramics.
Pilot project II: Eawag office building
(Coordination: Judit Lienert)
At Eawag, the first NoMix toilet (www.wost-man-ecology.se) was
installed in 1997 and then removed in 2003 following blockages. In
2000, another two NoMix toilets (www.dubbletten.nu) and three
waterfree urinals connected to a tank were installed close to the
cafeteria and auditorium. The urine and the installations were used
for research purposes (Nova 2 to Nova 5). Social scientific studies
revealed that the NoMix toilets were widely accepted (Nova 1).
However, many Eawag staff in particular noted that the technology is not yet fully mature. Visitors tended to be less critical. It
was essential for the sanitary installations to be well maintained;
otherwise, complaints were – legitimately – quickly raised. The
new Eawag office building (www.forumchriesbach.eawag.ch),
which was opened in 2006, is fitted with the NoMix technology
throughout. It can thus be tested on a large scale even after the
completion of the Novaquatis project.
Pilot project III: Vocational college
(Claude Lüscher, Maximilian Mayer)
From 2002 to 2004, the University of Applied Sciences Northwestern Switzerland (FHNW) operated three NoMix toilets and
six waterless urinals in a vocational college [3]. The main objective was to test various models and to gain experience. Users’
attitudes were favourable. In surveys, many respondents indicated
that they were prepared to adapt their behaviour when using the
NoMix toilet – e. g. by sitting to urinate (Nova 1). The functioning
of the NoMix toilets and urinals was generally satisfactory. Certain
urinals gave off an unpleasant odour, especially when they were
not cleaned in accordance with the manufacturer’s instructions;
thus, proper maintenance is essential. Low concentrations of
Nova PP – Pilot projects
Connection to the future: A plumber installs a NoMix toilet in an apartment
(Photo Timur Bürki)
Pointing the way to NoMix: A familiar symbol leading to an as yet unfamiliar
innovation at Eawag (Photo Yvonne Lehnhard)
nitrogen and phosphorus were measured in the tank – presumably
because the urine was diluted with flushing water. The experience
gained was very valuable when it came to designing the tank and
pipes for the larger-scale pilot project IV.
are undertaken by staff. The public is prepared to use hygienic
NoMix facilities (Nova 1). In private homes, however, restraint
should be exercised; people are not always keen to live with
the disadvantages of NoMix toilets in their own bathroom. Pilot
projects in households are possible if the residents know what to
expect. Ideally, these should be accompanied by social scientific
studies to assess the many unresolved research questions [1].
A clearly defined goal and early involvement of all parties will
contribute to the success of NoMix pilot projects ([1]; “Practical
guide”). This innovation has far-reaching implications for urban
wastewater management. NoMix pilot projects should therefore
be supported by wastewater authorities and other policymakers at
all levels, as well as by private investors. We hope that the experience gained from Novaquatis will encourage other actors to adopt
the NoMix technology in spite of the obstacles encountered.
Pilot project IV: Basel-Landschaft
cantonal library in Liestal
(Coordination: Gerhard Koch)
The first Swiss pilot project involving full implementation of the
NoMix technology was launched by the utilities agency of Canton
Basel-Landschaft (AIB) at the cantonal library which opened in
2005 ([4]; www.kbbl.ch). The goal is to evaluate alternatives for
urban wastewater management and to test the NoMix technology.
This is one of the first projects worldwide to use modern urine
treatment technology on a pilot-plant scale. Urine from approximately 200 000 visitors per year is stored in a tank and transported
by tanker to a treatment plant, which receives financial support
from the Swiss Federal Institute of Technology (ETHZ) Novatlantis
project (www.novatlantis.ch). Following laboratory tests at Eawag
(Nova 4), a combination of electrodialysis and ozonation was
selected as the treatment process [5]. This should permit the
production of a stable, hygienized fertilizer, free of micropollutants. The product was granted provisional approval (see “Practical guide”), and it was field-tested in 2006 (Nova 6). A research
institute was commissioned by Novaquatis to study user attitudes
towards the NoMix toilets. The findings among the general public
were as positive as those obtained in earlier surveys (Nova 1).
To facilitate development of the NoMix technology, further pilot
projects are required. These are complicated, costly – and risky,
since any innovation can be torpedoed by adverse experience. In
the longer term, therefore, improved NoMix toilets will be needed
(Nova 2).
In public buildings, pilot projects can be readily implemented
using today’s NoMix toilets if the increased maintenance efforts
Final Report of the Transdisciplinary Project Novaquatis
”What do I have to do, Mum?” Children in particular find it difficult to aim
correctly (Photo Ruedi Keller)
Practical guide
The right mixture: To clean NoMix toilets without contaminating the urine, one
can use a 10 % citric acid solution and a microfibre cloth (Photo Ruedi Keller)
applicable once a certain critical mass is reached. Realistic objectives may include further development of elements such as
urine treatment, or studying the acceptance of NoMix toilets in
Would a NoMix toilet be a suitable option for me?
(Judit Lienert, Tove A. Larsen)
Fundamental considerations. If you find urine source separation
an attractive approach and would like to install NoMix toilets, your
intentions are to be applauded! However, in putting your plans
into practice, you will need to consider a number of key points, as
the technology is still in its infancy. You should have a clear idea
of what you are seeking to achieve with NoMix toilets. Does this
goal justify the higher costs – and, for example, the significantly
greater cleaning efforts required? Urine-diverting toilets do not yet
fully meet the standards of today’s conventional lavatories.
One of the main problems is the build-up of urine scale – leading inevitably to blockages (Nova 2). For this reason, like waterfree
urinals, NoMix toilets need to be well maintained. In addition,
many elements of the NoMix system are not yet fully developed
or ready for the market; for example, a urine treatment process is
only offered by a single company. In Sweden, it is recommended
that urine should be stored for six months for hygienization before
being used as a fertilizer. In Switzerland, however, urine-based fertilizers require approval and have to fulfil stringent requirements.
Novaquatis has accumulated several years’ experience with
NoMix pilot projects. This guide provides an overview of the
current state of our knowledge and includes references to key
sources (for detailed information see [1]). It should enable fundamental aspects to be considered at the planning stage, so that
your NoMix project stands the test of everyday life.
Early involvement of all stakeholders. Particularly if NoMix
toilets are to be installed in private homes, it is essential to involve
all parties at a very early stage. Among the important stakeholders are household members, caretakers and property managers,
cleaning staff, architects and plumbers, wastewater treatment
plant operators, engineers and planners, ­ local officials, authorities, policymakers and scientists. Projects can only succeed if
all parties are prepared to accept the drawbacks of the NoMix
Legal aspects, use of urine. As connections to sewers and waste­water treatment plants are mandatory in Switzerland, approval is
required for NoMix pilot projects [2–3]. A contract should specify
who is to assume the risks (malfunctions, accidents) and who is to
bear the costs if installations have to be removed. We recommend
the conclusion of written agreements with the main parties (e. g.
The fate of the urine must be determined at the beginning of
the project. Fertilizers require approval, which in Switzerland is
granted by the Federal Office for Agriculture [4–5]. In what is currently the only (provisional) Swiss fertilizer licence for urine – from
the BL cantonal library – strict quality requirements are specified
(Nova PP). Urine can also be used for nutrient peak shaving at
wastewater treatment plants (Nova 3) or for development of treatment processes (Nova 4). If a project is designed, for example, to
investigate user attitudes in daily life, urine may also be released
into the sewers without being further used (Nova 1).
Before the start of the project
Objective. The objective of the NoMix pilot project has to be
clearly defined in advance. While this sounds trivial, it is crucial to
success – the higher-level goals of urine source separation (e. g.
reducing nutrient load at wastewater treatment plants, nutrient
recycling) are not relevant in an individual project. They are only
Final Report of the Transdisciplinary Project Novaquatis
Technological aspects
NoMix toilets and waterfree urinals. Undiluted urine from men
can be collected with the aid of waterfree urinals. A wide variety
of systems and models are commercially available [6]. In all cases,
Practical guide
Essential maintenance: To prevent blockages, urinal components are exchanged according to manufacturer’s recommendations (Photo Ruedi Keller)
Urine on tap: At the withdrawal point, urine collected in Forum Chriesbach
can be pumped into a tanker as required (Photo Karin Güdel)
urinals need to be carefully maintained to avoid troublesome
odours, unsightly stains and blockages. Good ventilation can help
to prevent odour problems.
Two flushing systems are used in NoMix toilets [7]: e. g. in
Dubbletten appliances, the urine compartment is flushed separately with a small amount of water (8 ml–2 dl). This saves water
– provided that users dispose of urine-soiled paper in a bin, rather
than using the full flush for this purpose. Although more recent
NoMix toilets are fitted with a conventional dual-flush system
(small: 2–3 l, full: 6–7 l), the urine tank receives only a small amount
of water (2.5 dl, Gustavsberg) or – thanks to an ingenious closure
mechanism – none at all (Roediger). Thus, while these NoMix
toilets do not use less water than a modern dual-flush appliance,
lightly soiled paper does not have to be disposed of separately.
The disadvantage of the Roediger model is that the urine drain
is only opened when the user is seated. With other models, an
accurate aim remains sufficient for male users – among whom
sitting is unpopular. Here, waterfree urinals may offer an alternative. Women, for their part, are reluctant to sit on public toilets
for hygiene-related reasons. Some users find it difficult to adopt
the required sitting position. Children in particular have problems
targeting the right compartment, which increases the need for
cleaning. However, Dubbletten offers a separately available child
seat [7].
or inaccessible sections, and a large diameter (65–110 mm) (for
further information see [1, 6]). In waterfree urinals, precipitates
are frequently collected in siphons, which have to be regularly
replaced to avoid drainage problems.
Cleaning and maintenance. Broad acceptance can only be
gained with sound maintenance. Public sanitary facilities have to
be cleaned at least daily. If it is necessary to ensure that no water
and only harmless chemicals enter the urine tank, cleaning with,
for example, a damp microfibre cloth and a 10 % citric acid solution is recommended [1].
One of the main problems affecting NoMix toilets is the buildup of urine scale, which blocks siphons and pipes (Nova 2, [8–9]).
To prevent the formation of precipitates, the urine drain can be
regularly flushed with acid [1]. Blockages can be removed using a
strong acid or caustic soda, or by mechanical means [8–9]. Certain design measures can help to avoid blockages later on: pipes
with the steepest possible slope (at least 2–5 %), no tight bends
Urine storage, transport and treatment. The urine tank should
have a capacity appropriate to the requirements of the project,
should be water- and odour-tight and resistant to urine and strong
acids. It should have an overflow outlet and possibly also include
a stirring mechanism, sampling points and a pump [1, 6]. As urine
tanks often emit unpleasant odours, good ventilation is extremely
For information on urine transport, see Nova 3. A struvite reactor
permitting the recovery of phosphorus from urine is available from
Huber [10]. All other urine treatment processes are still at the
laboratory or pilot stage and await further development (Nova 4).
Perhaps this could be an objective of your NoMix project?
Costs. Innovations are always more expensive than tried-andtested technologies, for which considerable demand – and a large
market – already exists. Urine source separation is no exception to
this rule. NoMix toilets cost about twice as much as conventional
models. Additional costs are associated with urine pipes, tank,
transport and treatment. The costs will be further increased if
prototypes are required. Accordingly, no information on prices is
included here (for an overview, see [6–7]).
Although there are good reasons for installing NoMix toilets, anyone intending to launch a project of this kind should be aware that
these are pioneering efforts. Compared with conventional options,
you should expect higher costs and other drawbacks with NoMix
toilets. We wish you every success with your project. Our team
will be glad to offer advice, further information and the detailed
article [1]: [email protected]
Final Report of the Transdisciplinary Project Novaquatis
Larsen, T.A., W. Gujer (1996) Separate management of anthropogenic
nutrient solutions (human urine). Water Science and Technology 34(3–4):
Larsen, T.A., W. Gujer (1997) The concept of sustainable urban water
management. Water Science and Technology 35(9): 3–10.
Larsen, T.A., I. Peters, A. Alder, R. Eggen, M. Maurer, J. Muncke (2001)
Re-engineering the toilet for sustainable wastewater management.
Environmental Science & Technology 35(9): 192A–197A.
Larsen, T.A., M. Maurer, K.M. Udert, J. Lienert (submitted) Nutrient
cycles and resource management: Implications for the choice of wastewater treatment technology. Accepted for presentation at IWA Advanced
Sanitation Conference, Aachen, 12.–13.3.2007, submitted to Water
Science and Technology.
Wilsenach, J.A., M. Maurer, T.A. Larsen, M.C.M. van Loosdrecht (2003)
From waste treatment to integrated resource management. Water
Science and Technology 48(1): 1–9.
Nova 1 – Acceptance
[1] Pahl-Wostl, C., A. Schönborn, N. Willi, J. Muncke, T.A. Larsen (2003)
Investigating consumer attitudes towards the new technology of urine
separation. Water Science and Technology 48(1): 57–65.
[2] Thiemann, K. (2006) Neue Dinge für eine nachhaltige Entwicklung.
Ansätze zu einer Kulturpsychologie nachhaltigen Produktdesigns.
Inauguraldissertation der Philosophisch-humanwissenschaftlichen
Fakultät der Universität Bern zu Erlangung der Doktorwürde.
University of Bern, Switzerland.
[3] Lienert, J., K. Thiemann, R. Kaufmann-Hayoz, T.A. Larsen (2006) Young
users accept NoMix toilets – a questionnaire survey on urine source
separating toilets in a college in Switzerland. Water Science and
Technology 54(11–12): 403–412.
[4] Lienert, J., T.A. Larsen (2006) Considering user attitude in early development of environmentally friendly technology: A case study of NoMix
toilets. Environmental Science & Technology 40(16): 4838–4844.
[5] Larsen, T.A., J. Lienert (2003) Societal implications of re-engineering the
toilet. Water Intelligence Online March 2003. UNIQUE ID: 200303006.
Nova 2 – Sanitary technology
[1] Larsen, T.A., J. Lienert (2003) Societal Implications of re-engineering the
toilet. Water Intelligence Online March 2003. UNIQUE ID: 200303006.
[1] Larsen, T.A., W. Gujer (1996) Separate management of anthropogenic
nutrient solutions (human urine). Water Science and Technology 34(3–4):
[2] Huisman, J.L., S. Burckhardt, T.A. Larsen, P. Krebs, W. Gujer (2000)
Propagation of waves and dissolved compounds in sewer. Journal of
Environmental Engineering-ASCE 126(1): 12–20.
[3] Larsen, T.A., W. Gujer (1997) The concept of sustainable urban water
management. Water Science and Technology 35(9): 3 –10.
[4] Rossi, L., J. Lienert, W. Rauch (2004) At-source control of urine to
prevent acute wet-weather impacts of ammonia. Presented at
5th International Conference on Sustainable Techniques and Strategies in
Urban Water Management (NOVATECH), May 2004. Proceedings, vol 2,
Lyon, France: 919 –926.
[5] Rauch, W., D. Brockmann, I. Peters, T.A. Larsen, W. Gujer (2003)
Combining urine separation with waste design: an analysis using a
stochastic model for urine production. Water Research 37(3): 681–689.
[6] Rossi, L., J. Lienert, T.A. Larsen (submitted) Real-life efficiency of urine
source separation: experience from households and an institutional
setting. Submitted to Water Research.
[7] Spörri, C., I. Peters, T.A. Larsen, P. Reichert (in preparation) A micro­
simulation model for optimizing urine tank management strategies of
NoMix toilets. In preparation for Water Research.
Nova 4 – Process engineering
[1] Maurer, M., W. Pronk, T.A. Larsen (2006) Treatment processes for source
separated urine. Water Research 40(17): 3151–3166.
[2] Udert, K.M., C. Fux, M. Münster, T.A. Larsen, H. Siegrist, W. Gujer (2003)
Nitrification and autotrophic denitrification of source-separated urine.
Water Science and Technology 48(1): 119–130.
[3] Udert, K.M., T.A. Larsen, W. Gujer (2005) Chemical nitrite oxidation
in acid solutions as a consequence of microbial ammonium oxidation.
Environmental Science & Technology 39(11): 4066 –4075.
[4] Ronteltap, M., M. Maurer, W. Gujer (2007) Struvite precipitation thermodynamics in source-separated urine. Water Research 41(5): 977–984.
[5] Ronteltap, M., M. Maurer, W. Gujer (in press) The behaviour of pharmaceuticals and heavy metals during struvite precipitation in urine. Accepted
for publication in Water Research.
[6] Pronk, W., H. Palmquist, M. Biebow, M. Boller (2006) Nanofiltration for
the separation of pharmaceuticals from nutrients in source-separated
urine. Water Research 40(7): 1405 –1412.
[7] Pronk, W., M. Biebow, M. Boller (2006) Electrodialysis for recovering
salts from a urine solution containing micropollutants. Environmental
Science & Technology 40(7): 2414–2420.
[2] Udert, K.M., T.A. Larsen, W. Gujer (2003) Biologically induced
precipitation in urine-collecting systems. Water Science and Technology:
Water Supply 3(3): 71–78.
[8] Pronk, W., S. Zuleeg, J. Lienert, B. Escher, M. Koller, A. Berner, G. Koch,
M. Boller (submitted) Pilot experiments with electrodialysis and ozonation
for the production of a fertilizer from urine. Accepted for presentation at
IWA Advanced Sanitation Conference, Aachen, 12.–13.3.2007, submitted
to Water Science and Technology.
[3] Udert, K.M., T.A. Larsen, M. Biebow, W. Gujer (2003) Urea hydrolysis
and precipitation dynamics in a urine-collecting system. Water Research
37(11): 2571–2582.
[9] Maurer, M., P. Schwegler, T.A. Larsen (2003) Nutrients in urine:
energetical aspects of removal and recovery. Water Science and
Technology 48(1): 37–46.
[4] Udert, K.M., T.A. Larsen, W. Gujer (2003) Estimating the precipitation
potential in urine-collecting systems. Water Research 37(11): 2667–2677.
[5] Udert, K.M., R. Högger, T.A. Larsen, W. Gujer (2004) Urinausfällungen in
Urinalen und NoMix-Toiletten. Installateur 11-2004: 46–48. Vereinigung
Schweizerischer Sanitär- und Heizungsfachleute, VSSH, www.vssh.ch.
[6] Udert, K.M., R. Högger, T.A. Larsen, W. Gujer (2004) Fällungsprodukte
in Urinalen und NoMix-Toiletten. gwa (Gas Wasser Abwasser) 12/2004:
913 – 920.
Nova 3 – Storage and transport
Final Report of the Transdisciplinary Project Novaquatis
Nova 5 – Micropollutants
[1] Escher, B.I., N. Bramaz, M. Maurer, M. Richter, D. Sutter, C. von Känel,
M. Zschokke (2005) Screening test battery for pharmaceuticals in
urine and wastewater. Environmental Toxicology and Chemistry 24(3):
750 –758.
[2] Escher, B.I., N. Bramaz, R.I.L. Eggen, M. Richter (2005) In vitro
assessment of modes of toxic action of pharmaceuticals in aquatic life.
Environmental Science & Technology 39(9): 3090–3100.
[4] Maurer, M., P. Schwegler, T. A. Larsen (2003) Nutrients in urine: energetic
aspects of removal and recovery. Water Science and Technology 48(1):
37– 46.
[3] Escher, B.I, R.I.L. Eggen, U. Schreiber, Z. Schreiber, E. Vye, B. Wisner,
R.P. Schwarzenbach (2002) Baseline toxicity (narcosis) of organic
chemicals determined by in vitro membrane potential measurements in
energy-transducing membranes. Environmental Science & Technology
36(9): 1971–1979.
[5] Maurer, M., D. Rothenberger, T.A. Larsen (2005) Decentralised wastewater treatment technologies from a national perspective: at what cost
are they competitive? Water Science and Technology: Water Supply 5(6):
[4] Escher, B.I., N. Bramaz, M. Richter, J. Lienert (2006) Comparative
ecotoxicological hazard assessment of beta-blockers and their human
metabolites using a mode-of-action-based test battery and a QSAR
approach. Environmental Science & Technology 40(23): 7402–7408.
[5] Escher, B.I., W. Pronk, M. J.-F. Suter, M. Maurer (2006) Monitoring the
removal efficiency of pharmaceuticals and hormones in different treatment processes of source-separated urine with bioassays. Environmental
Science & Technology 40(16): 5095–5101.
[6] Eggen, R.I.L., B.- E. Bengtsson, C.T. Bowmer, A.A.M. Gerritsen,
M. Gibert, K. Hylland, A.C. Johnson, P. Leonards, T. Nakari, L. Norrgren,
J.P. Sumpter, M.J.-F. Suter, A. Svenson, A.D. Pickering (2003) Search
for the evidence of endocrine disruption in the aquatic environment:
Lessons to be learned from joint biological and chemical monitoring in the
European Project COMPREHEND. Pure and Applied Chemistry 75(11–12):
2445 –2450.
[7] Lienert, J., T. Bürki, B.I. Escher (submitted) Reducing micropollutants
with source control: Substance flow analysis of 212 pharmaceuticals in
feces and urine. Accepted for presentation at IWA Advanced Sanitation
Conference, Aachen, 12.–13.3.2007, submitted to Water Science and
[8] Lienert J., K. Güdel, B.I. Escher (submitted) Screening method for
ecotoxicological hazard assessment of 42 pharmaceuticals considering
human metabolism and excretory routes. Submitted to Environmental
Science & Technology.
Nova 6 – Agriculture
[1] Lienert, J., M. Haller, A. Berner, M. Stauffacher, T.A. Larsen (2003) How
farmers in Switzerland perceive fertilizers from recycled anthropogenic
nutrients (urine). Water Science and Technology 48(1): 47–56.
[2] Pahl-Wostl, C., A. Schönborn, N. Willi, J. Muncke, T.A. Larsen (2003)
Investigating consumer attitudes towards the new technology of urine
separation. Water Science and Technology 48(1): 57–65.
[3] Simons, J. (2006) N- und P-Wirksamkeit von Substraten der zentralen und
dezentralen Abwasserbehandlung. Kapitel für Dissertation am Institut
für Pflanzenernährung, Universität Bonn, Deutschland. Publication in
international journal planned (with J. Clemens and J. Lienert).
[4] Simons, J., J. Lienert, J. Clemens (2006) Phosphorous-availability from
substrates of conventional and non-conventional waste water treatment
systems. Proceedings of the IWA (International Water Association) World
Water Congress, Beijing, China, 10.–14.9.2006.
Nova 7 – Evaluation
[1] Larsen, T. A., I. Peters, A. Alder, R. Eggen, M. Maurer, J. Muncke (2001)
Re-engineering the toilet for sustainable wastewater management.
Environmental Science & Technology 35(9): 192A –197A.
[2] Larsen, T.A., M. Maurer, K.M. Udert, J. Lienert (submitted) Nutrient
cycles and resource management: Implications for the choice of wastewater treatment technology. Accepted for presentation at IWA Advanced
Sanitation Conference, Aachen, 12.–13.3.2007, submitted to Water
Science and Technology.
[3] Wilsenach, J.A, M.C.M. van Loosdrecht (2006) Integration of processes
to treat wastewater and source-separated urine. Journal of Environmental
Engineering-ASCE 132(3): 331–341.
[6] Borsuk, M.E, J. Lienert, M. Maurer, Larsen, T.A. (in preparation) Using
decision analysis to chart a path for innovative toilet technology. In
preparation for Decision Analysis.
Nova 8 – China
[1] Huang, D.-B., H.-P. Bader, R. Scheidegger, R. Schertenleib, W. Gujer
(in press) Confronting limitations: new solutions required in urban water
management in Kunming City. Journal of Environmental Management
doi: 10.1016 / j.jenvman.2006.05.004 (available online).
[2] Medilanski, E., L. Chuan, H.-J. Mosler, R. Schertenleib, T.A. Larsen (in
press) Identifying the institutional decision process to introduce
decentralized sanitation in the city of Kunming (China). Accepted for
publication in Environmental Management.
[3] Medilanski, E., L. Chuan, H.-J. Mosler, R. Schertenleib, T.A. Larsen
(2006) Wastewater management in Kunming, China: a stakeholder
perspective on measures at the source. Environment and Urbanization
18(2): 353–368.
[4] Kunming Insitute of Environmental Science (2005) Implementation,
monitoring and promotion of urine-separating dry toilets in
Zhonghe Village, Kunming, China.
[5] Chuan, L., L. Ronghuai, F. Jinming, A. Morel, E. Medilanski (2005) Social
acceptance of urine-diverting dry toilets in Zhonghe Villlage, Kunming,
Nova PP – Pilot projects
[1] Lienert, J., T.A. Larsen (submitted) Pilot projects in bathrooms: a new
challenge for wastewater professionals. Available from:
[email protected]
[2] Larsen, T.A., J. Lienert (2003) Societal implications of re-engineering the
toilet. Water Intelligence Online March 2003. UNIQUE ID: 200303006.
[3] Mayer, M. (2004) Urinseparation – Praktische sanitärtechnische
Erfahrungen aus 2-jährigem Betrieb einer Anlage zur separaten
Gewinnung von Urin. Kurzbericht der Fachhochschule Nordwestschweiz
[4] Kühni, M., G. Koch, E. Ott (2002) Zukunftsweisende Sanitär- und
Abwassertechnik – erstes Pilotprojekt der Schweiz für Urinseparierung,
-speicherung und -steuerung im technischen Massstab. gwa (Gas Wasser
Abwasser) 11/2002: 827– 835.
[5] Pronk, W., S. Zuleeg, J. Lienert, B. Escher, M. Koller, A. Berner, G. Koch,
M. Boller (submitted) Pilot experiments with electrodialysis and ozonation
for the production of a fertilizer from urine. Accepted for presentation at
IWA Advanced Sanitation Conference, Aachen, 12.–13.3.2007, submitted
to Water Science and Technology.
Practical guide
[1] Lienert, J., T.A. Larsen (submitted): Pilot projects in bathrooms: a new
challenge for wastewater professionals. Available from:
[email protected]
Final Report of the Transdisciplinary Project Novaquatis
[2] Swiss water pollution control bill: Bundesgesetz über den Schutz der
Gewässer (24.01.1991). SR-Nr 814.20. Download:
www.admin.ch/ch/d/sr/c814_20.html, last accessed: 13.12.2006, email:
[email protected]
[3] Swiss water pollution control regulation (28.10.1998). SR-Nr 814.201.
Download: www.admin.ch/ch/d/sr/c814_201.html, last accessed:
13.12.2006, email: [email protected]
[4] Fertilizer book regulation (28.02.2001). SR-Nr 916.171.1. Download:
www.admin.ch/ch/d/sr/c916_171_1.html, last accessed: 13.12.2006,
email: [email protected]
[5] Fertilizer regulation (10.01.2001). SR-Nr 916.171. Download:
www.admin.ch/ch/d/sr/c916_171.html, last accessed: 13.12.2006,
email: [email protected]
[6] ecosan/GTZ (2005). Technical data sheets for ecosan components. Draft
versions available at: www.gtz.de/en/themen/umwelt-infrastruktur/
wasser/9397.htm. Deutsche Gesellschaft für Technische Zusammenarbeit
(GTZ) GmbH; ecological sanitation (ecosan), last accessed: 13.12.2006,
contact: Christine Werner, [email protected]
[7] Homepages NoMix toilets: www.dubbletten.nu ([email protected]),
www.wost-man-ecology.se ([email protected]),
www.gustavsberg.com ([email protected]), www.roevac.com
([email protected]), last accessed: 13.12.2006.
[8] Udert, K.M., R. Högger, T.A. Larsen, W. Gujer (2004) Urinausfällungen in
Urinalen und NoMix-Toiletten. Installateur 11-2004: 46 –48. Vereinigung
Schweizerischer Sanitär- und Heizungsfachleute, VSSH, www.vssh.ch
[9] Udert, K.M., T.A. Larsen, W. Gujer (2003) Biologically induced
precipitation in urine-collecting systems. Water Science and Technology:
Water Supply 3(3): 71–78.
[10]Hans Huber AG, Berching, Germany. Information: www.huber.de –
process engineering – decentralized wastewater treatment – the future
begins with ourselves, [email protected], last accessed: 13.12.2006.
Final Report of the Transdisciplinary Project Novaquatis
Project management Novaquatis
Dr. Tove A. Larsen, Eawag, Department of Urban Water
Management (SWW)
Dr. Judit Lienert, Eawag, Department of Urban Water
Management (SWW)
Dr. Max Maurer (Feb – Sep 2001), Eawag, Department of
Environmental Engineering (Ing)
Project management team
Dr. Tove A. Larsen, Eawag, Department of Urban Water
Management (SWW)
Dr. Judit Lienert, Eawag, Department of Urban Water
Management (SWW)
Dr. Alfredo Alder, Eawag, Department of Environmental
Chemistry (Uchem)
Prof. Dr. Rik Eggen, Eawag, Department of Environmental
Toxicology (Utox), Directorate
Dr. Max Maurer, Eawag, Department of Environmental
Engineering (Ing)
Prof. Dr. Irene Peters (until 2002), former Eawag, currently:
Institute of Urban, Regional and Environmental Planning,
TU Hamburg-Harburg, University of Sciences and
Technology, Germany, www.tuhh.de/stadtplanung/
Steering committee
Michel Carrard, Federal Office for the Environment (FOEN),
Water Division, Bern, Switzerland, www.bafu.admin.ch
Walter Dinkel (until 2003), former Cantonal Department of
Industrial Utilities (AIB), Canton Basel-Landschaft, currently:
Chief Engineer of the Civil Engineering Department, Berne,
Switzerland, www.bve.be.ch/site/index/tba.htm
Prof. Dr. Willi Gujer (since 2004), Eawag, Directorate /
Institute of Environmental Engineering (IfU), ETH Zürich,
Switzerland, www.ifu.ethz.ch
Roland Högger, Head of Envrionment and Sustainability,
Geberit International AG, Jona, Switzerland,
Dr. Markus Koch, Office of Waste, Water, Energy and Air
(AWEL), Switzerland,
www.awel.zh.ch / www.gewaesserschutz.zh.ch
Regula Mäder, Municipal Council Health and Environment,
Opfikon, Switzerland, www.opfikon.ch/de/politik/exekutive/
Dr. Walter Richner, Agroscope Reckenholz-Tänikon
Research Station (ART), Water Protection / Nutrient and
Pollutant Flows, Switzerland, www.art.admin.ch
Toni von Arx (since 2004), Cantonal Department of Industrial
Utilities (AIB), Canton Basel-Landschaft, Liestal, Switzerland,
Prof. Dr. A.J.B. Zehnder (until 2004), former Director
of Eawag, currently: President of the ETH Board, Zürich,
Switzerland, www.ethrat.ch/
Nova 1 – Acceptance
Nova 1-1 Prof. Dr. Claudia Pahl-Wostl, former Eawag,
currently: Chair for Resource Flow Management,
Institute of Environmental Systems Research,
University Osnabrück, Germany,
Nova 1-2 Prof. Dr. Ruth Kaufmann-Hayoz, Interdisciplinary
Centre for General Ecology (IKAÖ), University of
Bern, Switzerland,
Kirsten Thiemann, Interdisciplinary Centre
for General Ecology (IKAÖ), University of Bern,
Switzerland, www.ikaoe.unibe.ch
Nova 1-3 Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Nova 2 – Sanitary technology
Nova 2-1 Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
PD Dr. Bernhard Truffer, Eawag, Department
of Comprehensive Innovation Research in Utility
Sectors (Cirus)
Nova 2-2 Dr. Kai Udert, Eawag, Department of
Environmental Engineering (Ing)
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Prof. Dr. Willi Gujer, Eawag, Directorate /­ Institute
of Environmental Engineering (IfU), ETH Zürich,
Schweiz, www.ifu.ethz.ch
Nova 3 – Storage and transport
Nova 3-1 Prof. Dr. Wolfgang Rauch, former Eawag,
currently: Unit Environmental Engineering, University of Innsbruck, Austria,
Prof. Dr. Willi Gujer, Eawag, Directorate /­ Institute
of Environmental Engineering (IfU), ETH Zürich,
Switzerland, www.ifu.ethz.ch
Dr. Tove Larsen, Eawag, Department of Urban
Water Management (SWW)
Nova 3-2 Dr. Luca Rossi, former Eawag, currently:
Environmental Science and Technology Institute
(ENAC-ISTE), Ecological Engineering Laboratory,
Ecole Polytechnique Fédérale de Lausanne
(EPFL), Switzerland, http://ecol.epfl.ch/
Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Nova 3-3 Christian Spörri, Eawag, Department of Systems
Analysis, Integrated Assessment and Modelling
Final Report of the Transdisciplinary Project Novaquatis
Prof. Dr. Peter Reichert, Eawag, Department of
Systems Analysis, Integrated Assessment and
Modelling (Siam) / Directorate
Prof. Dr. Irene Peters, former Eawag, currently:
Institute of Urban, Regional and Environmental
Planning, TU Hamburg-Harburg, University of
Sciences and Technology, Germany,
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Nova 4 – Process engineering
Nova 4-1 Dr. Kai Udert, Eawag, Department of
Environmental Engineering (Ing)
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Prof. Dr. Willi Gujer, Eawag, Directorate /­ Institute
of Environmental Engineering (IfU), ETH Zürich,
Schweiz, www.ifu.ethz.ch
Nova 4-2 Mariska Ronteltap, Eawag, Department of
Environmental Engineering (Ing)
Dr. Max Maurer, Eawag, Department of
Environmental Engineering (Ing)
Prof. Dr. Willi Gujer, Eawag, Directorate /­ Institute
of Environmental Engineering (IfU), ETH Zürich,
Schweiz, www.ifu.ethz.ch
Nova 4-3 Dr. Wouter Pronk, Eawag, Department of Urban
Water Management (SWW)
Prof. Dr. Markus Boller, Eawag, Department of
Urban Water Management (SWW)
Nova 5 – Micropollutants
Nova 5-1 PD Dr. Beate Escher, Eawag, Department of
Environmental Toxicology (Utox)
Prof. Dr. Rik Eggen, Eawag, Department of
Environmental Toxicology (Utox), Directorate
Nadine Bramaz, Eawag, Department of
Environmental Toxicology (Utox)
Nova 5-2 Dr. Marc Suter, Eawag, Department of
Environmental Toxicology (Utox)
René Schönenberger, Eawag, Department of
Environmental Toxicology (Utox)
Nova 5-3 Dr. Alfredo Alder, Eawag, Department of
Environmental Chemistry (Uchem)
Dr. Christa McArdell, Eawag, Department of
Environmental Chemistry (Uchem)
Elvira Keller, Eawag, Department of
Environmental Chemistry (Uchem)
Nova 5-4 Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
PD Dr. Beate Escher, Eawag, Department of
Environmental Toxicology (Utox)
Karin Güdel, Eawag, Department of Urban Water
Management (SWW)
Timur Bürki, Eawag, Department of Urban Water
Management (SWW)
Final Report of the Transdisciplinary Project Novaquatis
Nova 6 – Agriculture
Nova 6-1 Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
Michel Haller, former Eawag / student
ETH Zürich
Alfred Berner, Research Institute of Organic
Agriculture (FiBL), Frick, Switzerland,
Michael Stauffacher, Department of
Environmental Sciences (UNS), ETH Zürich,
Switzerland, www.uns.ethz.ch
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Nova 6-2 Jürgen Simons, Institute of Crop Science and
Ressource Conservation (INRES), Department of
Plant Nutrition, University Bonn, Germany,
Dr. Joachim Clemens, Institute of Crop Science
and Ressource Conservation (INRES), Department
of Plant Nutrition, University Bonn, Germany,
Nova 6-3 Martin Koller, Research Institute of Organic
Agriculture (FiBL), Frick, Switzerland,
Alfred Berner, Research Institute of Organic
Agriculture (FiBL), Frick, Switzerland,
Dr. Wouter Pronk, Eawag, Department of Urban
Water Management (SWW)
Steffen Zuleeg, Eawag, Department of Urban
Water Management (SWW)
Prof. Dr. Markus Boller, Eawag, Department of
Urban Water Management (SWW)
Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
Nova 7 – Evaluation
Nova 7-1 Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Dr. Max Maurer, Eawag, Department of
Environmental Engineering (Ing)
Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
Dr. Kai Udert, Eawag, Department of
Environmental Engineering (Ing)
Nova 7-2 Dr. Mark Borsuk, former Eawag, currently:
Dartmouth College, Hanover, New Hampshire,
USA, www.dartmouth.edu/
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Dr. Max Maurer, Eawag, Department of
Environmental Engineering (Ing)
Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
Nova 8 – China
Nova PP – Pilot projects
Nova 8-1 Dong-Bin Huang, former Eawag, currently:
Institute for Environmental Decisions (IED),
ETH Zürich, Switzerland, www.ied.ethz.ch/
Dr. Hans-Peter Bader, Eawag, Department of
Systems Analysis, Integrated Assessment and
Modelling (Siam)
Ruth Scheidegger, Eawag, Department of Systems
Analysis, Integrated Assessment and Modelling
Roland Schertenleib, Eawag, Directorate
Prof. Dr. Willi Gujer, Eawag, Directorate / Institute
of Environmental Engineering (IfU), ETH Zürich,
Switzerland, www.ifu.ethz.ch
Nova 8-2 Dr. Edi Medilanski, former Eawag, currently:
High Performance Organisations AG,
8807 Freienbach, Switzerland, www.hpo.ch
Liang Chuan, Sustainable Development Research,
Yunnan Academy of Social Sciences (YASS),
650034 Kunming, China
Zhi Guoqiang, Kunming Institute of Environmental
Science (KIES), 650032 Kunming, China
Prof. Dr. Hans-Joachim Mosler, Eawag,
Department of Systems Analysis, Integrated
Assessment and Modelling (Siam)
Roland Schertenleib, Eawag, Directorate
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Dr. Judit Lienert (project coordination), Eawag,
Department of Urban Water Management (SWW)
Dr. Judit Lienert (project coordination), Eawag,
Department of Urban Water Management (SWW)
Claude Lüscher, University of Applied Sciences
Northwestern Switzerland (FHNW), School of Life
Sciences, Institute of Ecopreneurship (IER), Basel,
Switzerland, www.fhnw.ch/lifesciences
Maximilian Mayer, University of Applied Sciences
Northwestern Switzerland (FHNW), School of Life
Sciences, Institute of Ecopreneurship (IER), Basel,
Switzerland, www.fhnw.ch/lifesciences
Gerhard Koch (project coordination), Cantonal
Department of Industrial Utilities (AIB),
Canton Basel-Landschaft, Liestal, Switzerland,
Practical guide
Dr. Judit Lienert, Eawag, Department of Urban
Water Management (SWW)
Dr. Tove A. Larsen, Eawag, Department of Urban
Water Management (SWW)
Contact, Publisher: Eawag, P.O. Box 611, 8600 Duebendorf, Switzerland, Phone +41 (0)44 823 55 11, Fax +41 (0)44 823 50 28,
[email protected], www.novaquatis.eawag.ch
Citation: Larsen, T. A., Lienert, J. (2007) Novaquatis final report. NoMix – A new approach to urban water management.
Eawag, 8600 Duebendorf, Switzerland
Text and editors: Tove A. Larsen, Judit Lienert, Eawag
Assistant: Karin Güdel, Eawag
Linguistic revision: Martina Bauchrowitz, Andri Bryner, Eawag and volltext.ch, Joachim Lienert, 8303 Bassersdorf, Switzerland
English translation: Jeff Acheson, 4103 Bottmingen, Switzerland
Layout: SLS Nadler, 8700 Küsnacht, Switzerland
Format: Yvonne Lehnhard, Eawag
Cover: The synthesis of Novaquatis is based on many research projects on urine source separation: 1) concerning scaling of urine in pipes (large photo),
2) in private bathrooms (above), 3) in the laboratory (centre) and 4) in pilot projects, for instance in China (below). Photos: Ruedi Keller, Yvonne Lehnhard,
Edi Medilanski.
Copyright: Reproduction possible on request. Please contact the editors.
Note: The report appears also in German
Printed: On original recycled paper
Publication date: 7th March 2007
Final Report of the Transdisciplinary Project Novaquatis
Novaquatis – a cross-cutting Eawag project
The transdisciplinary research project Novaquatis is concerned with urine source sepa­ration
as a new element in wastewater management. The goals are to improve water pollution control
by reducing inputs of nutrients and micro­pollutants, and to close nutrient cycles.
From 2000 to 2006, this cross-cutting project explored the poten­tial of urine source separation
– also known as NoMix ­technology. Novaquatis comprises nine work packages, largely
organized around the various stages of a nutrient cycle (see ­Figure on page 2). Participa­ting
in the project were researchers from the fields of sociology, economics, ­natural sciences and
engineering. They worked closely together with the sanitary technology industry, local
authorities and a fast-industrialising country – ­China. The main results of the project are
presented in this booklet.
While urine accounts for less than 1 % of total wastewater ­volume, it contains 50–80 % of all
the nutrients in wastewater – and these ­components have to be degraded at wastewater
treatment plants Many micropollutants, i. e. residues of pharmaceuticals and hormones from
human metabolism, also enter wastewater via urine. Urine source separation could simplify –
or remove the need for – nutrient elimination at wastewater treatment plants. Nutrients
recovered from urine could be recycled to agriculture, and micro­pollutants directly removed.
The NoMix technology helps to save water and increases the flexibility of the entire wastewater
management system. It could thus make a significant contribution to resolving global water
pollution control issues.
Eawag is a Swiss-based and internationally linked aquatic research institute committed to an
ecological, economical and socially responsible management of water – the primary source
of all life. It is part of the ETH domain and carries out research, teaching and consulting. Eawag
acts as an important link between science and practical application.
Fly UP