- Sanitary and in-house installations (GIZ/Roediger Vacuum)
- Plant technology (Huber SE)
- Operation and monitoring (THM/RWTH Aachen)
- Quality of the products / Storage of urine (University of Bonn/RWTH Aachen)
- Agricultural production / Legal situation (University of Bonn)
- Acceptance (RWTH Aachen/University of Bonn)
- Economic feasibility (GIZ/University of Bonn)
- International adaptability (GIZ)
The responsible partners for each focus point are given in brackets.
1) Sanitary and in-house installations
In the main building of the GIZ headquaters located in Eschborn, 23 waterless urinals of Keramag and 38 RoeVac© NoMix toilets have been installed for the source separation of the wastewater streams.
Within this project component, the RoeVac© NoMix toilets are tested in a continuous-operation mode and necessary modifications are made.
In the course of the project several modifications of the technical components of the RoeVac© NoMix toilets were carried out. In spring 2010 the urine separation valves were modified and potential leakages could be minimised. Furthermore, the Bowden cables were optimised. To reduce the deposition of urine scale, the interior of the valve was smoothened.
Furthermore, experience from continuous operation are documented and recommendations for technical and organisational enhancements are assessed. The documentation is kept in an operation diary, where data of monthly controls and routine maintenance (every six months) are listed. The results have shown that the average lifetime of a valve is 221 days. The most frequently changed components are the Bowden cable and the valve. The main reason for this is that they are the most intensely used components of the RoeVac© NoMix toilets. The most frequent troubles were caused by urine scale depositions and incrustations. However, these depositions are not just a particular problem in this project, they generally occur in public toilets. To prevent precipitation of urine scale no technical solutions are currently known, except of thorough and regular cleansings with adequate detergents.
Publications of this project component "Sanitary and in-house installations"
This component was led by Roediger Vacuum GmbH and supported by GIZ. back to top
2) Plant technology
TREATMENT OF URINE IN A PRECIPITATION REACTOR
Due to dwindling fossil phosphorus ressources it is necessary to preserve the existing resources and search for long-term alternatives. One alternative source for phosporous is urine. For this reason urine is treated with the help of a chemical-physical process in a precipitation reactor. In this process, the crystalline magnesium-ammonium-phosphate (MAP; also known as struvite) is produced by adding magnesium oxide, which is considered to be a valuable fertiliser in agriculture.
The installation of the MAP precipitation reactor took place in May 2010. The MAP production is running. More information can be obtained in the attachments.
TREATMENT OF BROWNWATER WITH MBR
Over the last years the membrane technology has proven of the value for treatment of wastewater and the production of process water. The procedural combination of membrane ultrafiltration and activated sludge process optimise the bioloical treatment process. In many regions space in cities is limited, because of the high population increase. With the use of a MBR it is possible to treat wastewater within a limited area available. After removal of the solids by the use of a primary screen in pre-treatment, the brownwater (faeces and flush water) is treated in a membrane bioreactor (MBR). Here, detrimental substances, as well as solid, bacteria and almost all viruses will be degraded or rather restrained. Bathing water quality is produced fulfilling EU regulations. Due to microbiological properties, permeate can be used as process water in buildings and for irrigation in agriculture without any problems.
The brownwater treatment plant was installed in June 2011.
TREATMENT OF GREYWATER WITH MBR
Membrane bioreactors are also very effective in treating greywater (the kitchen and wash water). The treated water fulfils the EU regulations for bathing water and is well-suited for in-door usage as process water. For example it can be used for toilet flushing, heating and air conditioning. The process water can be also used for irrigation in agriculture or for gardening.
The greywater treatment plant was installed in May 2011.
Publications of this project component "Plant technology"
The lead of this component was HUBER SE.
The treatment lants were deinstalled at the end of the project in December 2012.
Pictures of the deinstallation are available at the SuSanA Flickr album. back to top
3) Operation and monitoring
The measures regarding operation consisted of the steering, control and monitoring of the treatment plants by remote monitoring; the elimination of disturbances and breakdowns; regular inspection and maintenance; refilling of consumables. Furthermore, the relevant basic parameters were analysed in urine, brownwater and greywater to gain further information on the characteristics of the wastewater streams. Until now, only little information was available on the composition of the wastewater streams from the office buildings.
The reactor works in a semi-automated batch mode. One cycle describes following process steps: filling of the precipitation tank, dosing of the precipitation agent, stirring, solidifying and sedimenting, draining the mixture into the filter bags, drip-off of the supernatant urine through the filter bags. At the beginning of a cycle, up to 40 l of urine are led into the funnel-shaped precipitation tank coming from one of the four storage tanks. Afterwards an adequate amount of MgO (ß-factor 1.5) is added as a precipitation agent by the dosing unit. The MgO is welded in a bag made of polyvinyl alcohol. Through contact with the liquid the thermoplastic synthetic dissolves within a minute and the MgO is agitated with the urine. The magnesia is bonding with the phosphate and ammonium and forms MAP (magnesium-ammonium-phosphate). After a solidifying (the MAP crystals need approximately 30 min) and sedimentation time of approximately 90 min the MAP enriched urine (about 5 l) and the urine supernatant (about 35 l) are getting drained into different filter bags with a pore size of 10 µm. 20 of these cycles build a batch. Because there is space for 5 filter bags within the reactor, the bags are filled four times each with urine supernatant or MAP enriched urine. After four fillings, the bags rotate to the next spot and are filled with the respective component. Within 20 cycles (1 batch) each filter bag is filled four times with urine-supernatant and four times with enriched urine before they are ready for the following processing. Within this experiment an amount of 0.7 to 1.3 g of MAP could be extracted per liter urine, using technical magnesium oxide.
Attendance and maintenance
Following tasks have to be done on a regularly base to guarantee the operation: functional check of all pumps and engines, checkup of the dosing-unit, control of the sensors, control of the urine tanks, inspection and documentation of the operating parameters, cleaning of incurred depositions and cleaning of the urine tanks and pipes. These general maintenance, need a time exposure of approximately 70 min per batch.
The processing steps for the MAP production includes the manufacturing of magnesium oxide bags through weighing and heat sealing, handling of filter bags, emptying and drying of the collected MAP. Time requirements are approx. 100 min per batch.
The produced MAP is preserved in plastic bags of 10 g each and handed over to interested persons for experimental purposes or is used within the field trials of the University of Bonn. Consumables for the MAP reactor are the precipitation agent magnesium oxide, the polyvinyl alcohol bags and the needle felt filters, where the MAP gets collected. The cost for magnesium oxide is 0.31 € per dosing unit of 14 g, which is used for one cycle. The costs of magnesium oxide for 1 l urine are 0.0075 €. Projected onto the amount of urine that accrues during a whole year the cost adds up to 350 €/a. The needle felt filters cost 3 € per piece. With a life time of 4 cycles or 160 liter of urine, the total costs are 870 €/a.
Problems that occurred during the precipitation where caused by larvae of flies that have entered the pipe system in the years before. They were responsible for a large part of the upcoming pollution in the tanks and pipe systems which have to be filtered before treating the urine. This leads to a higher expense of cleaning because the bevel seated mud flap that separates solid matters from the urine is getting blocked quickly in case of a higher appearance of the particular larvae. In this case the feed of urine to the reactor chamber is prevented. To minimize this disorder it is necessary to clean the mud flap every day of maintenance. To reduce the amount of maintenance required, the feed pipe to the reactor has been equipped with a filter element of 2.7 liter volume and a 0.8mm size of hole before the mud flap. The interval of cleaning has been essentially enhanced through this optimization.
The Saniresch MBRs were usually operated with a constant low sludge loading of 0.1 kg COD/(kg TS x d). Based on the measured concentrations of COD in the inlet and the biomass concentration in the active sludge reactor, the necessary permeate volume was calculated. By this mode of operation the transmembrane pressure varied between 45 and 75 mbar for the greywater plant and between 37 and 68 mbar for the brownwater plant. Intention was to create a trouble free and stable operation. This is especially important during the starting phase to allow the microorganisms to adjust to the composition of the wastewater. Usually membrane bioreactors operate with biomass concentrations of approximately 12 g/l. For reasons of operational stability, both reactors were operated with a constant biomass concentration of 4 g/l of the greywater and 8 g/l for brownwater. To prevent the membrane from fouling and scaling, the membrane is permanently overflown with air. For that reason oxygen is present in the system and prevents the nitrate to convert into elemental, gaseous nitrogen, which is only possibly under anoxic conditions. Thus only oxidation of ammonium to nitrate (nitrification) happens within the treatment. The reuse of water is the main motivation for grey- and brownwater treatment. The specific quality requirements for hygiene depend on the intended use. Relevant quality parameters are the BOD5 concentration (storage capacity), turbidity (aesthetic concerns) and the biological load (health risks).
At the beginning very high concentration of phosphorous (36 mg/l) were detected in the greywater. First presumptions pointed at the phosphorus containing dishwasher detergents that were used in the building. Analyses confirmed high phosphorous concentrations in the dishwasher tabs. After a gradual change to phosphorous free dishwasher agents a decline of the phosphorous concentration was detected. The change took place from mid of July to September 2011. When the phosphorous-containing dishwasher agents were depleted the amount of phosphorous dropped to a value of 13 mg/l. The average COD of the greywater was 640 mg/l. This is a high value for greywater compared to the brownwater (830 mg/l). The average COD of the resulting permeate was 30 mg/l. This leads to a cleaning capacity of 96% of membrane bioreactor. The measured ratio of the nutrients carbon to nitrogen to phosphorous was C : N : P = 100 : 2.3 : 1.2. This composition of the wastewater streams is in line with those described in literature.
Attendance and maintenance
Following activities were required for controlling and maintaining the greywater treatment:
Examining the general condition of the installation like density of fittings, function check, recording of settings like filling level, parameters etc. sampling of the greywater and analysis of the activated sludge, control of the transmembrane compression and the bubble formation, adjustment of the sludge loading and controlling of the floating sludge, execution of cleaning work like removal of deposition, cleaning of the screen basket, inspection of wearing parts, etc.
Attendance and maintenance
Following activities were required for controlling and maintaining the brownwater treatment:
Examining the general condition of the installation like density of fittings, manual flushing of the afflux and effluent pipes, function check, recording of settings like filling level, parameters etc., sampling of the greywater and analysis of the activated sludge, control of the transmembrane compression and the bubble formation, adjustment of the sludge loading and controlling of the floating sludge, execution of cleaning work like removal of deposition, cleaning of the screen basket, inspection of wearing parts, etc.
The average COD of the brownwater was 830 mg/l. The average COD of the resulting permeate was 23 mg/l. This leads to a cleaning capacity of 97% based on the membrane bioreactor. The measured nutrient ratio was C : N : P = 100 : 8.6 : 1.3, and is also in line with literature values.
The reactor room possesses an air connection to an actively via the roof discharging pipe. The connection of the facility to this existing exhaust system ventilates actively the reactors, the drying box, the reactor room as well as the urine tanks. The whole facility is sealed air tight to prevent odors. This is very important due to the fact that the treatment plant is set up in an office building. An elevator shaft that is nearby holds the risk to spread resulting emissions quite fast in the whole building. The investment cost for the room ventilation was 1200 €. The energy costs could be quantified to 2400 €/a for the used configuration and a volume related performance of 1526 m³/h.
REMOTE DATA TRANSMISSION
To guarantee an undisturbed operation of the facility even outside the office hours and to intervene at incidents immediately, the facility was equipped with a remote data transmission. This transmission technology provides access to all operating data of the decentralised plants from an external control station to evaluate their operating states. Regular data evaluation allows for the targeted control of equipment operation and early detection of certain tendencies. An alert unite was able to send alerts vie SMS to the plant manufacturer as well as service personell.
Publications of this project component "Operation and monitoring"
The leads of this focus point were the THM University of Applied Sciences and the RWTH Aachen. back to top
4) Quality of the products / storage of urine
A central aim of the measures for nutrient recovery from wastewater streams is to guarantee the best possible separation between valuable substances and pollutants. It is necessary to ensure a high-quality application of the nutrients. The pollutant concentrations in the recycled products are ideally not higher than the range of the concentrations in mineral fertilisers. This aspect will be assessed within the project component “quality of products”. The concentration of investigated pollutants will be compared with the existing legal limit values as well as with the limit values under discussion. The main focus will be on the fate of trace elements as well as ultra trace elements during and after the treatment. In particular, pharmaceuticals must not be found in the fertiliser product.
Through urine most of all ingested nutrients are excreted: about 80% of nitrogen and possadium, 60% of phosphorus and nearly 100% sulphur. These important nutrients are needed in agriculture. In addition most of pharmaceutical residues are also excreted through human urine. With this background, in 2010 and 2011 research on several pharmaceuticals within SANIRESCH was done. None of the samples which were taken from the urine tanks had Carpamazepine, Chloroquine and Sulfamethazine above the detection limit. Bisoprolol, Diclofenac, Metroprolol, Tramadol and Ibuprofen were detected in measurements in both years, even though the concentrations in 2011 were much lower compared to those of 2010. No reason could be found for this variation, due to the huge amount and variety of users.
No bacterial contaminations with Salmonellae, Clostridium or Psdeudomonas aeruginosa were observed in 2010.
AMOUNT OF COLLECTED URINE
To plan the application of urine as a fertiliser the amount of produced urine per working day has to be known. Since May 2011 the fill level of every urine storage tank has been measured at a ten second interval by way of electronic measuring probes. Thus it was found out that on average 174 l urine per working day are produced.
STORAGE OF URINE
Analyses were done to observe, whether pharmaceutical residues are decomposed during the storage of urine. This decomposition behaviour within the storage tanks of GIZ was quantified for the detected pharmaceutical residues of Bisoprolol, Carbamazepine, Chloroquine, Diclofenac, Metoprolol, Sulfamethazine, Tramadol and Ibuprofen. The respective storage conditions were observed. Additionally, storage conditions were simulated (e.g. variation of pH value) in laboratory tests to determine the influences of different storage parameters. The concentrations of pharmaceuticals in the urine were too low for elimination experiments. Therefore, the samples were each spiked with 100 µg agent per litre.
The experiments have shown that only Diclofenac and Sulfamethazine were decomposed up to 97% respectively 94%, but on different pH values. During a storage experiment, where the pH value of urine was kept constantly on 6.5, the elimination rates were only 29% for Diclofenac and 70% for Sulfamethazine. A change of the pH value during the storage of urine produced by a big amount of people like the GIZ staff members and which contains a mix of various pharmaceuticals does not show a clear elimination on pharmaceuticals in their entirety. The conclusion is that if urine is collected from a bigger community of people it is necessary to choose the application form of the precipitation product MAP (see below) to exclude a possible spread of pharmaceutical residues into the environment.
Also a possible loss of nutrients should be considered: After the urine was stored over a time period of six months (WHO recommends this time for a complete hygienisation) the total nitrogen concentration was decreased by 22 % - on all inducted pH values. However, a decrease of the phosphorus concentration, which is crucial for the application as a phosphorus fertiliser, was not determined.
Within the urine treatment by way of the MAP precipitation, a free-flowing powder is produced which contains the nutrients phosphorus and nitrogen and can be used as a solid fertiliser in agriculture. MAP (NH4MgPO4•6H2O) can be used as a P-based compound fertiliser for basal fertilisation and for keeping up the P-supply in the soil. An additional N-fertiliser is still necessary to cover the whole nutrient demand of the plants.
Earlier experiments of the ISA in Aachen with MAP which was produced from urine spiked with pharmaceuticals have shown that the small amount of pharmaceutical residues adhering to MAP can be removed by washing with a saturated MAP solution. Thus, these pharmaceutical residues are not soundly enclosed in the MAP crystals and subsequently the product can be applied as a fertiliser without further concerns. But it has to be considered that the washing process leads to a higher loss of potassium (46%), sodium (65%) and to a smaller loss of nitrogen (2%) and calcium (4%).
When implementing the MAP precipitation on a larger scale a washing would not be necessary, since no pharmaceuticals could be determined above the detection limit (LOQ <1 μg/g) in the MAP product produced from urine which was not spiked with pharmaceuticals.
DRYING OF MAP
The drying process of precipitated MAP is an essential working step before it can be used as a solid fertiliser. The drying effect leads to a clear decrease of the bacterial count in the dried product, because the microorganisms are not able to survive in MAP with water content below 20%.
The drying experiements which were done within SANIRESCH have shown that high temperatures cause a severe loss of nitrogen. When using the product as a fertiliser, this high amount of nitrogen loss has to be considered. The smallest nitrogen loss within the conducted experiments could be reached at a drying temperature of 30°C over a time of eight days (when the constancy of weight is reached).
SERVICE WATER FROM THE GREY- AND BROWNWATER TREATMENT
Within the ongoing operation monitoring nutrient contents and standard indicators are measured regularly. It was determined that the cleaning performance of the greywater treatment plant regarding COD is 95% and of the brownwater treatment plant 97%. The remaining concentration of 30 mg/l in the treated greywater and 23 mg/l in the treated brownwater enables sufficient storage ability as service water.
In the treatment plants an oxidation of ammonium to ammonium nitrate (nitrification) takes place. The membranes are continuously flooded with air to prevent blocking.
At the beginning of operation the phosphate concentration in the greywater was very high (36.3 mg/l). Dishwasher tabs used in the kitchens, which contained phosphate, were determined as the reason for the high concentrations. After switching to phosphate-free tabs the phosphate concentrations decreased to 13.3 mg/l.
In addition to these standard measurements regarding the nutrient content, the treated service water from the greywater plant was analysed to obtain the effectiveness of the decomposition of surfactants from the kitchens. Dilluted in water, these chemicals reduce the surface tension at the interface between the oil and water molecules and are therefore a common substance in detergents.
The service water from the greywater treatment plant was enriched by a factor of 50 to verify the surfactants by the way of liquid chromatography-mass spectrometry (LC-MS). During the positive ionisation to detect neutral surfactants, no distinct surfactant spectra were verified. During the negative ionisation to detect anionic surfactants, secondary and linear alkyl sulphonates from usual detergents were detected. Another result of the tests was that by means of the cleaning effectiveness of the greywater MBR reactor, the surfactants concentration in the treated service water is decreased by the factor of 10 compared to the untreated greywater inflow.
Furthermore pharmaceutical residues were obtained. As expected, no residues were found in the inflow and permeate of the greywater treatment plant. Microscopic tests were done for both treatment plants to verify the microbiological harmlessness of the treated service waters orientated on the quality standard of the European bathing water guideline. Considering the fact, that relevant bacteria were found only in very low bacteria counts (greywater: coliform bacteria: 0.7/ml, E. coli: 0.4/ml; brownwater: coliform bacteria: 2/ml, E. coli: 1/ml), both treated service waters meet the quality criteria of the bathing water guideline.
A microscopic image of the activated sludge of both treatment plants provided insight into the biocoenosis of the biological treatment stages and their cleaning effectiveness. The composition of the biocoenosis in the greywater treatment plant stands for stabile operation conditions. In the brownwater treatment plant indicator species were detected which indicate a high sludge age and thus a stabile operation condition.
This focus point was led in common by the University of Bonn and the RWTH Aachen. back to top
5) Agricultural production / legal situation
FIELD TRIALS ON FERTILISER EFFECTS
Fertiliser experiments in the open field are the main part of this component. The tests took place on parcels from the University of Bonn (Campus Kleinaltendorf). They are situated in the Lower Rhine Valley on the main terrace of the Rhine, one of the most important fruit-growing regions of Germany. In these experiments, the fertilising effect on the energy plant Miscanthus (“elephant grass”), the cereals spring wheat and spring barley and on maize are investigated. Additionally fava bean was fertilised to analyse the fertiliser effect on N-fixing plants (legumes). The fertilising effect from urine of the GIZ headquarters and MAP (product of the urine treatment in the MAP reactor) is compared with the effect of mineral fertiliser application (calcium ammonium nitrate and ammonium magnesium phosphate) and zero use of fertiliser. The liquid fertiliser was applied at ground level to assure a high infiltration into the ground and to keep the volatilisation on a low level. This was done by using a slurry tanker with multiple small bore hoses for ground application. The fertilisation with urine and MAP was successful on all plants. There were no differences in crop yield or maturing time compared to plants fed with artificial fertilisers.
Within this component the gaseous emissions of laughing gas (N2O) and ammonia (NH3) by using urine as a fertiliser were compared with the emissions of two kinds of fermentation residues from biogas plants. Laughing gas is a greenhouse gas and contributes 6% to the anthropogenic greenhouse effect. Additionally it is one of the biggest sources for ozone reduction. Agriculture is with 50% of overall emissions Germany’s biggest laughing gas emitter. Ammonia leads to an acidification in the environment and to an eutrophication in eco systems. E.g. in Germany the agricultural sector produces 95% of all ammonia emissions.
One type of the applied fermentation residues consisted of 86% cattle manure and 8% maize silage (GR1). GR2 consisted of 50% cattle-swine-manure and 43% maize silage. As well as before the fertilisers were applied at ground level to reduce volatilisation. The fertilised plant was spring barley. The ammonia emission on the urine parcels is with 3% of all applied NH4-N considerably lower compared to the emissions of the parcels fertilised with the fermentation residues where GR1 emitted 31% and GR2 emitted 17% of NH4-N. The N2O emission of urine (0.01% of the applied NH4-N) was about ten to fifty times lower compared to the emissions of the fermentations residues (0.57% GR1 and 0.11% GR2). Hence, when considering the emissions of laughing gas and ammonia urine performs much better than the fermentation residues and slurry. The main reason for thisis a better infiltration into the ground because of a lower percentage of solid matter.
To better assess the potential hazard caused by pharmaceuticals in urine for human health the behaviour of pharmaceutical residues which were applied by urine in spring wheat were analysed. Because of the extremely low active agent concentrations, a constant and precise controllable environment is needed which can be assured by greenhouse pot tests. Besides an analysis of untreated urine, the following substances were added to the GIZ urine in two different concentrations (0.1 and 1 mg): Estradiol, Atenolol, Carbamazepine, Diclofenac and Verapamil. Only Carbamazepine could be detected in the in corn and stems of summer wheat of the enriched urine. Other spiked agents could not be detected. The tests with untreated urine did not lead to any measurable agents in the plant.
In order to assess the effect of urine application on germination experiments with sun flower and spring wheat seeds were conducted. After direct application as well as after application with urine that had been diluted (10%), the germination showed to be inhibited. This is caused by the high salt concentrations in urine. Variations of the pH value showed no impact.
The application of urine with an average concentration of pharmaceuticals and with a concentration of pharmaceuticals ten times higher than the average concentration did not have any negative impact on the germination of sun flower and spring wheat. During the field trials no germination restraints could be determined. This is because no direct contact between seeds and urine exists. Additionally the soil has a buffering effect. However, it is recommended not to apply the urine and simultaneously sowing the crop.
The legal framework regarding the separation, treatment and utilisation of urine are clarified and advices for responsible administrative bodies to improve this framework are prepared. In Germany no corresponding guidelines regarding the usage of yellowwater / urine as fertiliser exist. The German legislation for placing fertilisers on the market (Fertiliser Ordinance and Fertiliser Regulation), the regulation regarding the application and implementation of fertiliser (the German Fertilising Regulation) as well as EU legislation are applicable. Corresponding to the Fertiliser Ordinance the application of the fertiliser is subject to authorisation. Authorisation exists when the fertiliser is listed in the appendix of the German Fertiliser Regulation, is legally distributed in another European Country or in an EFTA-member country. To place a new fertiliser on the market, an application for authorisation has to be submitted to the German Federal Ministry of Food, Agriculture and Consumer Protection. The Fertiliser Advisory Council consults about this submission. According to their advice the Federal Council modifies the fertiliser regulation. back to top
The acceptance of the innovative sanitation system and the utilisation of human urine is investigated within the SANIRSCH-project. In conjunction with the agricultural production / legal situation component farmers were asked if they would be willing to fertilise their agricultural crops with human urine. In a second study consumers were asked if they would find products fertilised with urine acceptable. Final results are expected in September 2012.
Another investigation (three-step survey) is carried out to identify user problems and develop counteractive measures. The focus is set on the expectations, desires, handling problems and general attitude of the users as well as the maintenance and cleaning personnel towards the new sanitation system (waterless urinals and urine-diversion flush toilets called NoMix toilets). The main issues of the user investigation are the handling of the system, hygiene, expectations towards the system (also regarding environmental issues), possible implementation in the private sector and reasons for operating errors and perceived complications.
First results show that from an user perspective the main problem is the low flushing force of the NoMix toilets. Users as well as cleaning and maintenance personnel state that the water pressure is too low, thereby preventing a thorough removal of residuals especially from the front part of the toilet bowl. This problem was also not solved by increasing the flushing volume per use to its maximum possible level. As an alternative users tend to flush the toilets more than once per toilet use. It is supposed that the reason for that can be found in the general design of the toilet bowls. From the perspective of the technical personnel no fundamental concerns about the applied technology were expressed.
Another highly stressed out problem is the odour nuisance emitted by the NoMix toilets and the urinals. The nuisance still existed after improving the valve seals in the toilets and the use of another type of smell stops in the urinals. Especially women show big concerns about the hygiene of the toilets. For an appropriate use women are obliged to sit down. Men can use waterless urinals with no serious behaviour modifications.
Generally the interviewed toilet users are well informed about the sanitation system and its functionality. The provided information materials are assessed as sufficient. A final survey is conducted in 2012. Based on a comparison between all three surveys more statements regarding the acceptance of the sanitation system will be provided.
The cleaning personnel expressed that they expected an easily manageable technology that would not worsen their working conditions. However, during a group discussion it was reported, that the situation deteriorated, since the cleaning of the NoMix toilets takes more time and is more complicated due to blockages that occur more often than before. Also the cleaning of the waterless urinals is more time-consuming, because of the need of regularly removing deposits on the smell stops itself as well as replacing broken ones. The additional molesting odour increases their discontent about the sanitation system.
The leads of this focus point were the University of Bonn and the RWTH Aachen. back to top
7) Economic feasibility
An important aspect for the sustainable success of projects is their economic feasibility. Therefore, within this project component, the investment and reinvestment costs of the system and the running costs for its operation were analysed. Additionally, the system was compared with a conventional wastewater system.
As economic factors having a particular high influence on the feasibility of the project the following were determined: triple pipe system, high costs for NoMix toilets, energy costs of the MBRs, high manual labor of the MAP precipitation process and the mineral fertilisers Calcium-Ammonium-Nitrate and Triple-Superphosphate.
The dynamic cost comparison of LAWA was selected as method. Based on scenarios the total project costs, the annual project costs as well as the dynamic project costs of the SANIRESCH scenarios were calculated along the LAWA guidelines. The two options “Office building” and “Agricultural application” were considered and verified within sensitive analyses.
Comparing the costs for SANIRESCH with today´s costs for conventional wastewater treatment and standard commercial fertiliser, the alternative system is more expensive for both “Office building” and “Agricultural application”. However, the sensitivity analyses show that a certain potential exists. The differences come especially through the higher running costs, which influence is bigger than the higher investment costs. However, the sensitivity analyses show that a certain potential exists. With augmented durability of the spare parts of the NoMix toilets in combination with reduced investment costs of sanitary equipment, the system can reach the cost level of a conventional system. The economic feasibility analysis of the agricultural application showed that both alternative fertilisers are more expensive. Today fertilisation with urine can be economic feasible when the framing conditions such as land prices are adequate, which is not the case in Eschborn.
If higher automation of the MAP precipitation is achieved the system can become economically feasible as well. To achieve this, the production costs have to stay below those for commercial phosphorus fertiliser. This requires a continuation of research and development for the MAP production.
The principal lead of this focus point was GIZ. GIZ worked together with the University of Bonn in assessing the feasibility of urine reuse. back to top
8) International adaptability
The analysis of the international adaptability of the three treatment systems a Magnesium-Ammonium-Phosphate (MAP) precipitation reactor and two membrane bioreactors (MBRs) treating the grey- and brownwater, designed for and used within the SANIRESCH project specifically focused on developing countries.
As method the utility analysis (UA) was chosen amongst a variety of other multi-criteria-decision making tools. The UA is generally used for comparing and prioritising complex projects or technologies according to a pre-defined target system. The objective was to design UA matrices that can be adapted and used widely to assess the successful implementation of new alternative sanitation systems. In the first step relevant criteria were defined, weighted and allocated with a rating factor. The main-criteria are health and hygiene, economic, technical, environmental as well as socio-cultural criteria. For each main-criteria a series of relevant sub-criteria were identified within literature reviews and weighted during several expert interviews.
Also the UA was used to identify global hotspots for the three technologies, where they can be implemented in a global context and demand can be expected. The criteria used for the hotspot analyses were those having worldwide data available: water scarcity, freshwater quality, nutrient- and fertiliser demand / availability, eutrophication, population density and rate of urbanisation.
Overall both, the design of the decision support tool as well as the hotspot analysis reveal a clear picture of the international adaptability of the technologies. However it has to be pointed out that aggregated data had been used for the analyses which do not allow detailed regional estimations and require further investigations for each single case.
The hotspot analysis for the MAP precipitation technology shows that the highest scores were achieved by countries with large population numbers, a high demand for food and hence intensive agricultural activities in countries such as India or Mexico. Another result was that African countries generally yielded low scores. This can mainly be explained by the high proportion of subsistence farming with low or non-existing demand for nutrient inputs in terms of industrial fertilisers.
The assessment of the international adaptability of the grey- and brownwatertreatment revealed similar results. For both plant types the MENA-countries that suffer from water scarcity and water quality achieved the highest scores. But also countries allocated in Central Asia, parts of South-East Australia or the west coasts of America were identified as hotspots. For the implementation of all three technologies only a couple of countries, 9 out of 58, showed good scoring results. Those are Australia, Mexico, China, Pakistan, Turkey, India, Iran, Peru and Spain. All of them show water scarcity in combination with high agricultural activity.
The lead of this component was GIZ. back to top