Managing wastewater in the city of the future. Decentralized wastewater and rainwater reclamation and use in Urban Agriculture

Transcription

1 Managing wastewater in the city of the future Decentralized wastewater and rainwater reclamation and use in Urban Agriculture Lettinga Associates Foundation for Environmental Protection & Resource Conservation

2 Decentralized wastewater and rainwater reclamation and use in Urban Agriculture Session 6. Case studies on sanitation systems for wastewater reuse in urban agriculture. Part 1 Dr. Claudia Pabon Pereira with contributions from Dr. Adriaan Mels, Dr.Katarzyna Kujawa- Roeleveld, Dr. Grietje Zeeman Lettinga Associates Foundation for Environmental Protection & Resource Conservation

3 Case studies from the developed world The Netherlands Desar approach Black water treatment in Wageningen Implementation in Sneek Other examples for greywater treatment Germany Lübeck-Flintenbreite Greenhouse village Lettinga Associates Foundation for Environmental Protection & Resource Conservation

4 The Netherlands Wastewater management: facts and figures (2002) Population Netherlands Households connected to sewer Sewer: total length 16.1 million 98.4% 86,452 km Wastewater treatment plants 389 Capacity 33 million p.e. Source: St. Rioned, 2004 Lettinga Associates Foundation for Environmental Protection & Resource Conservation

5 WTP Nieuwveer Picture: Waterschap Brabantse Delta

6 Drivers for current hype Active role of water boards (STOWA) and interest from sewer people Desire for INNOVATION in wastewater management Reducing nutrient loads to surface water Increasing attention for presence of pharmaceuticals and endocrine disrupters in water systems Large sewer renovations at hand Desire to decrease energy consumption Nutrient recycling? Lettinga Associates Foundation for Environmental Protection & Resource Conservation

7 Barriers Calculations for residential areas show that costs are (still?) significantly higher (both for urine and black water) Benefits not easily visible Final use as fertilizer difficult in The Netherlands (too much manure, strict legislation for human excreta) R&D not finished Lettinga Associates Foundation for Environmental Protection & Resource Conservation

8 Short time line

9 Current R&D projects in The Netherlands Transportable urine processing unit (truck) Removal of pharmaceuticals from hospital wastewater Struvite precipitation from mobile toilets Nitrification of urine for sulphide reduction in pressure sewers Measures to reduce pipe cloggings Effects of urine-fertilization on groundwater (pharmaceuticals) Concentration of urine by excess ventilation heat at office level Monitoring established projects Black water digestion Lettinga Associates Foundation for Environmental Protection & Resource Conservation

10 DeSaR concept discharge agriculture Removal micropollutants/ pathogens biogas Removal micropollutants/ pathogens (ozone) Nirogen removal struvite precipitation reuse nutrient rich product UASBseptic sludge black water kitchen waste hygienisation grey water treatment Lettinga Associates Foundation for Environmental Protection & Resource Conservation

11 Grey water Black water energy UASBseptic energy Reuse 95L per person per day Posttreatment UASB Posttreatme nt N-recovery/removal Lettinga Associates Foundation for Environmental Protection & Resource Conservation

12 DESAR approach Black water treatment Vacuum collection and transport to keep black water concentrated Digestion for energy recovery at local scale Use of remaining product as fertilizer (e.g. after composting) Lettinga Associates Foundation for Environmental Protection & Resource Conservation

13 Anaerobic treatment of black water and kitchen wastes 7 liters/ p.d -1 UASB Septic Tank

14 Different types of septic tanks Conventional septic tank UASB-septic tank Increasing sludge bed height >> HRT UASB Steady sludge bed height <<HRT

15 Treatment of Black water treatment UASB ST pilot Comparison : UASB-pilot 7 liters/ p.d -1 7 liters/ p.d -1 15

16 Grey water treatment Anaerobic treatment in a UASB Aerobic treatment sequencing batch V= 5 L; HRT= 20 h; C V = 3.6 L; HRT 5-72 h Temperature = C 16

17 DeSaR in Sneek Present & Future research Sneek, the Netherlands, housing estate of 32 houses; inhabitants are very much content with the vacuum toilets Lettinga Associates Foundation for Environmental Protection & Resource Conservation

18 DeSaR in Sneek Treatment 32 houses in a garage Gas collection in a gas bag on the roof Lettinga Associates Foundation for Environmental Protection & Resource Conservation

19 DeSaR in Sneek Vacuum collection & transport use 1 liter for flushing Producing 7 l/p.d -1 concentrated black water; saving l/p.d -1 Lettinga Associates Foundation for Environmental Protection & Resource Conservation

20 Anaerobic treatment of black water and kitchen wastes UASB Septic tank - temperature 25 C - 2 days liquid retention time - influent COD: 8-10 g/l - effluent COD: 2-3 g/l - gas production 11 m 3 CH 4 / cap.year UASB Septic Tank

21 Prototype vacuum kitchen grinder Lettinga Associates Foundation for Environmental Protection & Resource Conservation

22 Black water treatment; struvite precipitation demo scale Nitrogen and phosphorus ratio: 11 mgn/mgp; Molar base : 24 mol N/mol P; Applying struvite precipitation with sufficient Mg added, will theoretically result in recovery of almost: 100% of phosphate; Only recovery of Phosphate recovery: 1.6 % nitrogen; 0.28 kgp/p/y; phosphate is an endless resource; good quality phosphate is finished in years. 24 Lettinga Associates Foundation for Environmental Protection & Resource Conservation

23 Black water treatment and nutrient recovery CH 4 N 2 patho gens Black water vacuum toilets UASB (ST) stabilized sludge (reuse?) Struvite (MAP) precipitation MAP (fertilizer) Autotrophic N removal (OLAND) Sludge (return UASB) Final polishing? Discharge to surface water UASB (ST) Struvite OLAND HRT min =7d; T max = 30 o C t contact =30min HRT min =3.5d 25 Lettinga Associates Foundation for Environmental Protection & Resource Conservation

24 Grey water treatment in constructed wetlands Six examples in Netherlands and two under construction Wetlands are integrated in urban design Treated water is used to create urban waterscapes Sometimes treated grey water is used as 2 nd quality water Lettinga Associates Foundation for Environmental Protection & Resource Conservation

25 Greywater treatment in constructed wetlands Landscape architects on constructed wetlands Constructed wetlands are very interesting for urban design By integrating constructed wetlands in urban design there are hardly any extra costs Lettinga Associates Foundation for Environmental Protection & Resource Conservation

26 Grey water treatment and reuse in Drielanden, Groningen Constructed wetland Urban wasterscape Lettinga Associates Foundation for Environmental Protection & Resource Conservation

27 EVA Lanxmeer Constructed wetlands

28 EVA Lanxmeer, Culemborg Lettinga Associates Foundation for Environmental Protection & Resource Conservation

29 Ecological Settlement Lübeck-Flintenbreite Example of urban application: sewerless city in Germany Double-Houses Terraced Houses

30 Vacuum station and sewer in Lubeck (Germany) for blackwater; small diameter flexible pipes

31 Vacuum pipe Transport of blackwater Central technical building and biowaste stormwater infiltration in swales Vacuumtoilet Vakuumtoilette Biowasteshredder Greywater treatment in constructed wetlands Peri-Urban Settlement Lübeck-Flintenbreite (400 inhabitants) Vacuum-Biogas-System for blackwater plus biowaste (source: Otterwasser GmbH, Lübeck)

32 Digester in basement of community house

33 Vacuum Pumping Station for Blackwater Bio-Waste Inlet and Grinder Source: Otterpohl

34 Constructed wetland for the grey water

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36 Constructed wetlands - examples Rural environment (Sweden) Urban environment (Oslo) Lettinga Associates Foundation for Environmental Protection & Resource Conservation

37 Palsternackan Stockholm (1995): 51 appartementen, 160 bewoners (urine separation)

38 Figure 1: Concept of blackwater collection for biogas production, greywater and rainwater collection in sewer system (Meinzinger 2008) This concept is currently more or less realized in one district in Hamburg under the name 'Neues Wohnen in Jennfeld' respectively 'Hamburg Water Cycle in Jenfeld' by Hamburg Wasser (Rebbin, Gerbitz, & Friemert 2007). Lettinga Associates Foundation for Environmental Protection & Resource Conservation

39 Demonstration toilets in Watermuseum, Arnhem

40 Urine-Tank; 10 Persons;(Glass-Resin)

41 The user acceptance interviews showed a high appreciation of grey water treatment systems (marks between 7.1 and 8.0). The interviews showed an average lower satisfaction level for vacuum toilets compared to conventional toilets. These results can partially be explained by operational problems in two of the studied locations. Despite of the lower satisfaction, the appreciation was generally high, due to the water saving aspect of vacuum toilets (marks between 7.1 and 8.0 for the cases without operational problems compared to 7.1 for the conventional toilets). A large part of the respondents with vacuum toilets, i.e % of the respondents considers the sound of the flushing unpleasant, compared to 25% of the control group. Noise nuisance is also one of the most commonly mentioned disadvantages of the vacuum toilet system during the interviews. The maximal sound level of an average vacuum toilet is 12 db louder than an average conventional toilet (the quietest vacuum toilet has a difference of 10 db) and is experienced as disturbing by the larger part of the households. To make the vacuum toilet more acceptable to users the maximal sound production has to be reduced. Based on this investigation various options for reduction appear to be available, such as optimisation of the pipe diameters and sound reducing backplates. The combination of a silencer with a Jets vacuum toilet could result in a vacuum toilet with a maximal sound level that equals the sound of a conventional toilet.

42 User acceptance of vacuum toilets and grey water systems in The Netherlands, Norway and Germany Project (year of realization) Kaja Ås, Norway (1996) Torvetua Bergen, Norway (1997) Wohnen & Arbeiten - Freiburg, Germany (1999) Flintenbreite (2000) Casa Vita Deventer, The Netherlands (2007) Short description 24 student apartments equipped with a vacuum toilet system and a local grey water treatment system (biofilter + constructed wetland). 40 single houses equipped with a vacuum toilet system and two local grey water treatment systems (biofilter + constructed wetland). 14 apartments and 4 offices equipped with a vacuum toilet system and a membrane filter system for grey water treatment 30 houses equipped with a vacuum toilet system and two local grey water treatment systems (constructed wetlands). 32 new apartments equipped with a vacuum toilet system Telkamp et al Lettinga Associates Foundation for Environmental Protection & Resource Conservation

43 Wetland systems evaluation Comparative performance of constructed wetlands for decentralized treatment of grey water in the Netherlands, Germany and Norway These cases showed that the implementation of on-site grey water treatment systems combined with reuse of reclaimed water may lead up to 57% less drinking water consumption. The treatment performance of the wetlands was generally satisfactory, although a number of the studied systems did not monitor properly the systems due to high costs this imply and In The Netherlands: Het Groene Dak, Polderdrift, Drielanden, De some Waterspin operational difficulties with clogging because of inadequate In Sweden: Kaja and Tovertua In Germany: Flinterbreite maintenance. People perception of constructed wetlands is positive, health risk is inexistent and different schemes of management and operation can be implemented. Drivers The perception and opinion of neighborhood dwellers about the systems was generally positive. Most people enjoy the esthetical landscape element of the systems and the presence of water in their surroundings. Most interviewed users feel that these systems contribute positively to environmental awareness. Some of the drivers for the implementation were water saving. Reduction of water emissions, protection of surface water. The fact that the systems generally have a low maintenance requirement and low operational costs are also important for the high degree of satisfaction. Barriers The main barriers identified during the decision making process in the pilot cases are decentralize maintenance because of the responsibilities it implies for users, restriction in cleaning products and higher investment cost. In the cases located in Kaja, Tovertua and Flinterbreite there were no significant barriers during the decision making process. Some barriers have been evidenced during operational stage, such as lack of support by the governmental authorities to reduce the fees. Lettinga Associates Foundation for Environmental Protection & Resource Conservation

44 Average marks given by the households for the vacuum toilets and / or grey water systemsin the various projects User acceptance of vacuum toilets and grey water systems in The Netherlands, Norway and Germany Figure 1. Level of satisfaction of households with their vacuum toilet systems compared to a control group with conventional toilets (Wageningen Casa Vita Flintenbreite Wohnen & Arbeiten Torvetua Kaja Wageningen (conventional toilet) very satisfied satisfied neutral dissatisfied very dissatisfied Casa Vita Flintenbreite Percentage of interviewed households that considers the flushing sound of their toilet unpleasant 0% 20% 40% 60% 80% 100% Wohnen & Arbeiten Torvetua Average marks given by the households for the vacuum toilets and / or Kaja grey water systems in the various projects Casa Vita Flintenbreite Wohnen & Arbeiten Torvetua Kaja Wageningen Wageningen (conventional toilet) combined grey w0% ater system 10% and vacuum 20% toilet 30% 40% 50% 60% 70% 80% 90% conventional toilet grey w ater treatment 7.1 vacuum toilet

45 Greenhouse village ( ) Technical lay-out of Greenhouse Village A.R. Mels, N. van Andel, E. Wortmann, J. Kristinsson, P. Oei, J. de Wilt and G. Zeeman (2006)

46 Greenhouse village ( ) Climate control system of the greenhouse and the housing block A.R. Mels, N. van Andel, E. Wortmann, J. Kristinsson, P. Oei, J. de Wilt and G. Zeeman (2006)

47 Greenhouse village ( ) The carbon cycle of Greenhouse Village A.R. Mels, N. van Andel, E. Wortmann, J. Kristinsson, P. Oei, J. de Wilt and G. Zeeman (2006)

48 Greenhouse village ( ) Separate collection and treatment of black and grey water in Greenhouse Village A.R. Mels, N. van Andel, E. Wortmann, J. Kristinsson, P. Oei, J. de Wilt and G. Zeeman (2006)

49 Greenhouse village ( ) The water system of Greenhouse Village A.R. Mels, N. van Andel, E. Wortmann, J. Kristinsson, P. Oei, J. de Wilt and G. Zeeman (2006)

50 Greenhouse village ( ) The nitrogen balance of Greenhouse Village A.R. Mels, N. van Andel, E. Wortmann, J. Kristinsson, P. Oei, J. de Wilt and G. Zeeman (2006)

51 Greenhouse village ( ) Environmental costs and benefits in Greenhouse Village A.R. Mels, N. van Andel, E. Wortmann, J. Kristinsson, P. Oei, J. de Wilt and G. Zeeman (2006)