Urine Diverting Toilets in Climates with Cold Winters

There was post on the yahoo group ECOSANRES asking about Cold Climate toilets -Cold weather toilets.

A reply mentioned this PDF:

Urine Diverting Toilets in Climates with Cold Winters Technical considerations and the reuse of nutrients with a focus on legal and hygienic aspects.

While  the report is several year old,  the $h1t is still good and worthy of summarizing

basic facts:

Authors and Editors:

• Anna Richert Stintzing
• VERNA, Ecological Inc., Sweden
• Dr. Håkan Jönsson
• Dr. Caroline Schönning
• Kati Hinkkanen
• Dr. Elisabeth Kvarnström
• Dr. Zsofia Ganrot
• Margriet Samwel
• Sascha Gabizon
• Annemarie Mohr
• Publisher: WECF – Women in Europe for a Common Future
• Year:2007
• Pages:42   1.35 mb
• It is formatted 3 columns / page which doe not lend itself  well to computer screens and pdf readers
• It is a fast read to those in this field
• It is a good  read for someone who knows little about this field

Chapters/ sections

1 – Summary
2 – Dry Urine Diversion
3 – EU directives relating to dry urine diversion where urine and faeces
4 – Legal aspects
5 – Cold temperature aspects
-   Freezing of urine
-   Hygiene and treatment of urine
-   Pharmaceuticals and hormones
-   Hygiene and treatment of faeces
-   Technical aspects: construction and maintenance of
-    urine diverting toilets in climates with cold winters
-   Pipes for urine
-   Storage
-   Odour control with ventilation
-   System for reuse of urine and faeces in crop production
-   Home gardens
-   Large Scale Agricultural Production
6 – Examples from pilot projects and research from the northern hemisphere
7 – Knowledge gaps and identified research needs
8 – Annex

Three key points  from the Reportssummary are:

“There are functioning examples of dry urine diversion in regions in the world with cold winter climates. The examples presented in the report show that it is possible to arrange agricultural reuse of urine and faeces in large or small scale crop production.”

“The fact that there are only short periods during the year when urine can be used as a fertiliser place demands on a storage system for the urine. There are a few alternatives; one of the most economic may be to arrange storage on a farm, in covered storage containers previously used for animal urine.”

“There are still development needs and knowledge gaps. Some of these are related to temperate and cold climates, such as the fate of microorganisms in urine at temperatures below freezing. However, this should not be considered a major constraint to the development of dry urine diversion, since the risk is relatively low, and can be handled through combination with other hygienic activities.”

The report reprints 3  basic but useful  tables from other organizations:

1: Recommended guideline storage times for urinea based on estimated pathogen contentb and recommended crop for larger systemsc (WHO, 2006).

2: Requirements on storage and allowed crops for diverted human urine that is collected from larger systems. (Swedish EPA, 2002).

3: Recommendations for storage treatment of dry excreta and faecal sludge before use at household and large-scale (municipal) levels. The treatments assume no
addition of non-sanitised material (WHO, 2006).

Again the report is a quick and easy read, providing a good  preface to a much larger  document that needs to be written on the subject.    The report  ends  nicely,  saying  we need more  research :

“There are some definite areas where there is a need of systematic research and development (R&D). Some of these, especially related to winter climate aspects, are specified in the following text.

Research needs

One of the most discussed questions regarding urine diversion is the fate of pharmaceutical residues after excretion, and how this affects choice of collection and treatment of human excreta. Research on fate of pharmaceuticals in waste water treatment plants is being undertaken in Germany and Sweden. No known field studies are taking place on fate of pharmaceutical residues when urine or sewage sludge is applied to the soil. The current recommendation to use urine as a fertiliser in agriculture rests on the analysis that the soil system is well suited to digest harmful organic substances due to microbial life in the surface layers of soil. This would be an interesting field of study that can give valuable information on design of reuse systems.

Sanitisation of faeces is another aspect that needs attention. The WHO guidelines on the reuse of human excreta in agriculture mention the alkaline treatment by adding ashes or alkaline substances with a storage time of 6 month ( > 35 °C ) as a possible way to sanitise faeces, or 1,5 – 2 years storage time. The temperature intervals given do not cater for needs in temperate or cold climates, which means that knowledge on treatment of faeces in this region should be developed. Research on more simple and robust treatment methods is needed.

Suggested applied R&D projects

-   Establishment of new pilot projects and evaluation of existing projects. Monitoring and evaluation of existing dry urine diversion projects is a costefficient way of generating knowledge. Dissemination of results, regardless of if they are positive or negative, from existing pilots is vital. The establishment of new pilot projects will also contribute to the bank of knowledge.

-   Sanitisation of faecal fraction: research on requested storage in ambient or alkaline environment in temperate and cold climates (winters with temperatures far below zero).

-   Sanitisation of faecal fraction: research on the implementation of chemical sanitisation of faeces with urea. This is an interesting method, but the practical implications need to be studied and developed.

-   Sanitisation of urine: what happens in the urine when it is frozen and what are the implications for storage intervals?

-   Pharmaceutical residues: studies of soil system when urine is used as a fertiliser. Effect on microbial community, speed of decomposition. Comparisons with sewage sludge, farmyard manure.

-   Toilet design: development of risers and squat-plates for local production. Care given to needs of different users: children, disabled, elderly, men, women. Toilets of today need development since many do not divert as much urine as possible, and are unnecessarily difficult to clean.

-   Systems analysis from an economic point of view. Comparison of investment and maintenance costs of urine diversion systems and conventional sanitation.

-   Systems analysis from an environmental point of view. How do different activities affect the sustainability of the system, for example fertilisation strategies, choice of tank, joint measures or single toilets?

-   What are the economical incentives for implementation of urine diversion? How to design the economical system with the regard to municipal responsibility and financial support/ interactions. How should the systems be organized and which are the most important drivers for the different stake holders.”

other  related links

• Inactivation of bacteria and viruses in human urine depending on temperature and dilution rate.
• The Swedish Eco-Sanitation Experience pdf
• Ecosan Sanitation Facilities resources
• Ecosan_Toilets_in_Mongolia.
• Reuse of faeces and urine – Appropedia: The sustainability wiki

• Guidelines for the safe use of wastewater, excreta and greywater. Volume 1: Policy and regulatory aspects
• Guidelines for the safe use of wastewater, excreta and greywater. Volume 2: Wastewater use in agriculture
• Guidelines for the safe use of wastwater, excreta and greywater. Volume 3: Wastewater and excreta use in aquaculture
• Guidelines for the safe use of wastwater, excreta and greywater. Volume 4: Excreta and greywater use in agriculture
• Human urine – Chemical composition and fertilizer use efficiency

• Human Urine – Decomposition Processes and Nutrient Recovery

The Bill &Melinda Gates Foundation supports joint project by Swiss aquatic research institute and South African water utility

Urine as a Commercial Fertilizer?

14 October 2010 – press release reprint

In Eawag’s laboratory, process engineer Kai Udert carries out research on various reactors to separate nutrients and contaminants out of urine

The Bill & Melinda Gates Foundation supports joint project by Swiss aquatic research institute and South African water utility

The separate collection of urine provides innovative opportunities for the improvement of sanitation and the recycling of nitrogen, phosphorus and potassium. Urine separation is an excellent sanitation solution, particularly in places where classic sewer-based sanitation is not sustainable. The Bill & Melinda Gates Foundation is providing a grant of 3.0 million US dollars to support a joint project by the Swiss Federal Institute of Aquatic Science and Technology (Eawag) and the eThekwini Water and Sanitation utility (EWS) in South Africa to continue developing practical, community-scale nutrient recovery systems.

The project, covering a period of four years, focuses on the further development of technical solutions for urine processing for nutrient recovery. In addition, project participants, together with experts from the University of KwaZulu-Natal and the Swiss Federal Institute of Technology (ETH) Zurich, will study the logistics of collection and transport of urine from toilets to processing facilities. The Swiss aquatic research scientists and their partners in South Africa will also examine ways in which sanitation can be paid for by the production and sale of urine-based fertiliser, thus enabling a cheap, efficient and widely-accepted sanitation system to be set up.

Alternatives are urgently needed

There is a growing awareness that in many parts of the world an alternative is needed for the conventional sewer-based sanitation and central wastewater treatment system – if only for the reason that not enough water is available for drinking, let alone to be used for flushing. There is a pressing need to reduce the number of people with no access to basic sanitary facilities and safe drinking water, as required by the UN Millennium Development Goals (MDGs). As well as endangering people’s health, inadequate disposal of faecal material poses a risk to the drinking water supply and contaminates the natural environment. Last but not least, the global demand for fertiliser is so great that interest in local sources of nutrients is growing.

Successful preparatory work in Nepal

Eawag has many years of experience in the research of urine separation, also known as NoMix technology, and in 2007 completed the transdisciplinary Novaquatis project. Since then, Eawag’s project in Siddhipur near Kathmandu, Nepal, has demonstrated that urine processed to make the phosphorus-based fertiliser struvite can help to close regional nutrient cycles and promote awareness of the value of the nutrients contained in urine. Farmers participating in the scheme also benefit since they do not need to buy as much imported chemical fertiliser (www.eawag.ch/stun). «This experience plus the collaboration with an extremely progressive administrative department in Durban were important reasons for developing our project in South Africa for the next four years», says process engineer Kai Udert, who is the Eawag researcher in charge of the South Africa project.

Collaboration with an innovative water authority

Eawag can count on a forward-looking partner in the South African eThekwini region around Durban, since they have already carried out important pioneering work in the field of sanitation. EWS has been promoting urine-diverting dry toilets since 2002 and there are already around 90,000 such toilets in use. However, urine is simply soaked into the ground, which could create new problems in the longer term. A simple, combined system for nutrient recycling from urine will be developed . This will reduce the costs of sanitation, prevent pollution of water resources and produce fertiliser for the local market. «That’s a completely new way of thinking and not just a small step on an already well-trodden path», says Kai Udert.

More information: Dr. Kai Udert, Telephone +41 44 823 5360

The effects of urine storage conditions on struvite recovery

This Came up in a google news watch  – worthy of noting – originally published in 2006 by Elizabeth  Anne Tilley

Absract:

“Phosphorus, like oil, is a non-renewable resource that must be harvested from finite resources in the earth’s crust. An essential element for life, phosphorus is becoming increasingly scarce, contaminated, and difficult to extract. Struvite, or magnesium ammonium phosphate (MgNH₄P0₄.6H₂0) is a white, crystalline phosphate mineral that can be used as a bioavailable fertilizer and can be recovered from aqueous solutions such as digestor supernant. In response to diminishing water resources, increasing nutrient pollution, and largely unaffordable centralized treatment, a paradigm of Ecological Sanitation (EcoSan) has emerged. A central tenant of EcoSan technology is nutrient recovery; by separating urine from feces in the absence of water, urine can be used as a clean, concentrated nutrient source. Urine harvested in this manner is used as a liquid fertilizer with varying degrees of success and acceptance. This research examines the potential of urine to be a feedstock for struvite recovery. By recovering a sustainable source of phosphorus from urine, the prospect of appropriate sanitation and closed-loop nutrient systems, may move closer to reality. In laboratory experiments using synthetic and real human urine, different methods of preparing urine to be used as a feedstock for struvite recovery, were examined. The effect of temperature, faecal contamination, dilution, and headspace on stored nutrient levels was examined. The effect of adding different quantities of magnesium, at different times, on the amount of phosphorus that could be removed from solution, was also examined. An average of 70% of phosphorus could be removed from real urine in the form of struvite when magnesium was added to the urine solution after ureolysis had forced the precipitation of calcium and magnesium minerals; magnesium added before ureolysis began retarded the process. Dilution and the presence of wastewater were found to affect the rate of ureolysis but not the purity of the struvite recovered; recovered struvite was approximately 99% pure regardless of dilution or contamination. Based on a comparison of the results, synthetic urine was found to be representative of the general behaviour of real urine during struvite formation.”

download link is VERY slow:  ubc_2006-0678.pdf

EcoSan video focusing on Urine as Fertilizer

Here is great video showing  how the EcoSan toilet works, stressing:
1 You don’t need water to us  an EcoSan toilet, saving a precious resource
2  There is a huge benefit to use urine as a fertilizer

The video the workings of toilet itself. What I find wonderful is  that  this video  explains  & shows the full sequence of steps taken to  after urination to get the urine onto the the field as fertilizer. This is followed by a wonderful comparison of crop yields comparing side by side  fields, on fertilized with urine the other fertilized with commercial fertilizer.  The fields  fertilized with urine did better than the commercial fertilizers and at NO COST!!!! The video is in English and the location is Ethiopia. Several local experts are use to explain particular points.

Title Urine Diversion Toilets: advantages and use agriculture
a brief Ecosan Documentary by Andreas Wilkin c 2008
produced for the ROSA project
contact Franziska Meinzinger  f.meinzinger   @    tu-harburg.de
Technische Universitat Hamburg-Harburg TUHH
(Hamburg University of Technology)

WASHLink  Notes:  addition resources:

other  related YouTube videos (using following search terms)

ecosan urine	ecosan construction	ecosan watsan
ecosan design materials	ecosan fertilizer	ecosan toilet

WHO:

• Safe use of wastewater, excreta and greywater

Google  Scholar search

• Urine  fertilizer  sources