http://www.internal.eawag.ch/~maurer/abstracts/09larsen.html Urine separation-NOVAQUATIS project

D53LiteratureResearch Literature Research / D53Notes Notes

D53LiteratureResearch Literature Research / D53Notes Notes

Ureum of carbamide (NH__2__CONH__2__) , het diamide van koolzuur , is een bijzondere stabiele verbinding met sterk polaire eigenschappen . De oplosbaarheid van ureum in water is erg groot. ( 1080 gram per 1 liter bij 20 graden Celcius )

http://www.homepages.hetnet.nl/~b1beukema/ureumcyclus.html Ureumcyclus (Dutch)

Ureum of carbamide (NH2CONH2) , het diamide van koolzuur , is een bijzondere stabiele verbinding met sterk polaire eigenschappen . De oplosbaarheid van ureum in water is erg groot. ( 1080 gram per 1 liter bij 20 graden Celcius )

Figuur 1(page10)

Flocculatie/sedimentatie (Case 6) verdient nadere aandacht vanwege het lage energiegebruik en de lage kosten. Sedimentatietests op lab schaal leverden goede resultaten op. Op pilot schaal leek de beheersbaarheid (te) beperkt. Voor vervolgontwikkeling dient de aandacht uit te gaan naar een betere procesbeheersing. (page 21)

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Every 1000 kg of algae concists something about 500 kg carbon. In other words 1800 kg of CO__2__ (page 9)

zijn daarnaast in staat stikstofverbindingen (NH__4__+, NO__3__-) en fosfaat tot zeer lage restconcentraties (< enkele 10-tallen mg/l) uit effluenten te verwijderen.

energiesector kan een belangrijke bijdrage leveren aan reductie van de CO__2__ emissies. De teelt

De kweek van micro-algen kan plaatsvinden met eenvoudige inputs: energie uit zonlicht, CO__2__

+, NO__3__-) en fosfaat tot zeer lage restconcentraties (< enkele 10-tallen mg/l) uit effluenten te verwijderen.

voor hergebruik. Micro-algen zijn in staat stikstofverbindingen (NH__4__ +, NO__3__

worden verwijderd uit een effluent van bietsuikerproductie (NH__4__

CO__2__ vastlegging uit rookgas.

http://www.eet.nl/docs/EETK99005.pdf Breeding algae on urine

Every 1000 kg of algae concists something about 500 kg carbon. In other words 1800 kg of CO2 (page 9)

When urine in one form or another ends up in water it fertilizes different organisms, mainly vegetation and various algae. An abundant amount of nutritious sewage water is one of the reasons why so called blue-green algae (cyanobacteria) and the flowering of algae has increased. It is estimated that the amount nutrients found in one liter of urine is enough to produce about 1 kilogram of algae, provided that all the phosphorus and nitrogen oxides in the urine are used to the maximum.

The Mexican model of the urine-diverting toilet represents a modification of the Vietnamese double vault toilet. The urine is diverted and can be used as a liquid fertilizer (approximately 1:5 to 1:10 dilution with water).

dark green color to plants. The level of nitrogen added to

Nitrogen is also important from the point of view of nutrition

used in chemical fertilizer preparations.

There is a strong preference for the addition of a combination of soil and wood ash, which provides the desired effect of pathogen

better water pollution control with respect to nutrients and micro-pollutants and the possibility of closing the nutrient cycles

NOVA 4 is concerned with the processing of the urine solution and the possible production of a fertilizer product. It develops and tests different procedures to stabilize urine, to reclaim the nutrients (N, P, and K), and to eliminate micro-pollutants. A wide variety of elimination technologies for nutrient solutions already exist. However, the adaptation of these technologies for handling urine still needs efforts (<a href="#Larsen_01" class="tlink">Larsen and Boller, 2001</a>; <a href="#Maurer_02" class="tlink">Maurer et al., 2002</a>). Methods to recover nutrients from urine and the elimination of micro-pollutants are the main focus of this research project. Possible technologies are biological processes (e.g. bio film reactors), chemical processes (e.g. precipitation in fluidized bed reactors), and physical processes (e.g. membrane techniques). <br>

<p>Fresh urine solution does not contain any solids and has a slightly acid pH of 6.2 to 6.8. The high amount of biodegradable substrate triggers rapid microbial growth, which strongly alters the chemical composition of urine. One of the dominating reactions is the decomposition or hydrolysis of urea. This microbial catalyzed reaction produces ammonia and increases the pH to above 9. As a consequence the saturation for several phosphate minerals is exceeded and they precipitate. This precipitation can be a nuisance due to possible clogging of pipes (see <a href="NOVA2_e.html"class="tlink">NOVA 2</a>). On the other hand it enables the recovery of phosphorus and some nitrogen as solids.<br>

NOVA -4-2: Fresh urine contains nitrogen mainly in the form of urea, which is a very good fertilizer. However, urea hydrolysis to ammonia and bicarbonate during storage and transport are unwanted reactions. One possible strategy would be to directly treat fresh urine in such a way that urea is conserved. First experiments indicate that this stabilization can be achieved by filtration with micro- or ultra-filtration membranes. This however would imply decentralized treatment, which requires the development of very robust systems. Alternatively, technologies can be developed for the treatment of urine containing ammonia after urea hydrolysis.

NOVA 6, Agriculture: NOVA 6 focuses on agricultural aspects of the NoMix technology. In Switzerland, nutrients derived from human urine could in principle replace around 37 % of the N-demand, 20 % of the P-demand, and 15 % of the K-demand, which are today covered by artificial mineral fertilizers (Lienert et al., 2003). The original purpose of NOVA 6 was to investigate the possibilities and challenges of such a recycling strategy. A number of interesting research questions were formulated: local demand, acceptance and preferences of farmers, risks with respect to micro-pollutants in urine, hygienic aspects, and the environmental consequences of replacing synthetic fertilizers with a urine-based one. Unfortunately, it was not possible to fund the different research projects formulated by EAWAG researchers and external collaborators. Consequently, only a minor project based on a student investigation on the attitude of Swiss farmers towards the NoMix technology has been carried out in 2000 (NOVA 6-1). Possibly, a similar, but more thorough study will be performed later.

NOVA 6-1: How farmers in Switzerland perceive fertilizers from urine: The preferred type of product is a nitrogen fertilizer in form of ammonia nitrate. Most farmers preferred a grainy to a liquid fertilizer and rejected a fertilizer with urine odor. A hazard-free product is absolutely essential: 30 % of all farmers mentioned concerns regarding organic micro-pollutants in additional remarks.

Breeding algae on urine
This pdf-paper, based on Dutch multi-disciplined research, describes how the economically feasible production of algae result in biomass that can be used for generating energy as well as for extracting pigments for coloring.

http://www.laneta.apc.org/sarar/PDFS/closing-the-loop.pdf 1st international symposium on ecological sanitation

<p>Fresh urine solution does not contain any solids and has a slightly acid pH of 6.2 to 6.8. The high amount of biodegradable substrate triggers rapid microbial growth, which strongly alters the chemical composition of urine. One of the dominating reactions is the decomposition or hydrolysis of urea. This microbially catalyzed reaction produces ammonia and increases the pH to above 9. As a consequence the saturation for several phosphate minerals is exceeded and they precipitate. This precipitation can be a nuisance due to possible clogging of pipes (see <a href="NOVA2_e.html"class="tlink">NOVA 2</a>). On the other hand it enables the recovery of phosphorus and some nitrogen as solids.<br>

Some of these composting toilets involve the separation of urine from feces. This is done by urinating into a separate container or into a diversion device which causes the urine to collect separately from the feces. The reason for separating urine from feces is that the urine/feces blend contains too much nitrogen to allow for effective composting and the collected material can get too wet and odorous. Therefore, the urine is collected separately, reducing the nitrogen, the liquid content, and the odor of the collected material.
An alternative method of achieving the same result which does not require the separation of urine from feces does exist. Organic material with too much nitrogen for effective composting (such as a urine/feces mixture) can be balanced by adding more carbon material such as sawdust, rather than by removing the urine. The added carbon material absorbs the excess liquid and will cover the refuse sufficiently to eliminate odor completely. This also sets the stage for thermophilic composting because of the carbon/nitrogen balancing.

http://www.laneta.apc.org/sarar/PDFS/closing-the-loop.pdf Closing the loop