DEUS 21. Decentralized Urban Infrastructure System for water provision and sewerage. Dr.-Ing. Ursula Schließmann

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1 DEUS 21 Decentralized Urban Infrastructure System for water provision and sewerage Dr.-Ing. Ursula Schließmann Integrated Resource Management in Asian cities: the urban Nexus, Bangkok, June 25th 2013

2 Semi-decentralized water management Centralized systems: high investment, not flexible Semi-decentralized units: 1,000 50,000 inhabitants, depending on structure of settlement Short distances, less investment in sewers Recycling of water, energy, nutrients

3 References / examples from Germany

4 Demonstration site Heidelberg-Neurott 60 inhabitants + 30 population equivalents (inn, farming) KA Average 6.6 m 3 /d; max. 9.9 m 3 /d Pressure sewer system with 7 pumping stations Only domestic wastewater collected and treated, rainwater drained separately Aerobic Membrane Bioreactor installed in the former equipment house of the local fire brigade Started operation in 2005

5 Parameters in 2006 Parameter Average influent Requirement Average effluent mg/l COD NH4-N NO3-N 9.2 TN PO4-P Effluent complies with EU bathing water quality Nitrogen loads in influent 30% higher than expected

6 DEUS 21 in Knittlingen Demonstration project in development area: 105 plots Funded by German Ministry of Education and Research, Fraunhofer Society Innovations: Utilization of rainwater Vacuum sewer system Wastewater treatment: anaerobic membrane bioreactor

7 Water management in Knittlingen River

8 Utilization of rainwater Collection of rainwater from roofs and roads Storage in 3 cisterns (300 m 3 ) Treatment by ultrafiltration, activated carbon, ozone Purification up to drinking water quality possible, but relatively complex reasonable if no sources for water of better quality available Utilization for irrigation after simple treatment possible

9 Vacuum sewer system Inhabitants are connected to vacuum system via a collection chamber Central station creates vacuum of 0,5-0,7 bar Option: Vacuum toilets inside houses for less water consumption

10 Wastewater treatment in Knittlingen Anaerobic Membrane Bioreactor, operated since 2006

11 Anaerobic wastewater treatment Microorganisms grow in absence of oxygen Organic load is transformed into biogas (contains energy) No need for aeration (energy intensive) Low growth rate: little sludge for disposal No heating necessary (different from sludge digestion) Microorganisms have to be kept in system High concentration of nutrients in discharge Nitrogen and phosphorous have to be removed prior to discharge in water bodies possibility of utilization: recovery out of effluent or reuse of water

12 Energy and mass balance per capita and year

13 Reuse of treated wastewater Effluent from anaerobic treatment contains nutrients, usable for irrigation and fertilisation (agriculture, horticulture, parks) Membrane for sludge retention: effluent hygienic Salinisation of soil through irrigation has to be prevented Groundwater protection necessary

14 Concept for Böblingen-Dagersheim Around 25 existing houses, 80 development sites First pilot, later possibly extension to settlement with up to 6,000 inhabitants In Baden-Württemberg: 72,000 km public sewers, 150,000 km private connections Private connections frequently not tight, laws for inspection of private connections are prepared (high costs for plot owners) Idea: use this necessity to switch to separated sewer system Collect wastewater via vacuum sewer, rainwater via old gravity system Utilize energy in wastewater to heat public buildings

15 High-load digestion in the practical implementation High-load digestion in Heidelberg, 250,000 PE. High-load digestion with microfiltration AZV Schozachtal, 35,000 PE. High-load digestion with microfiltration for a sewage plant with 10,000 PE in Wutöschingen. PE = population equivalents

16 EtaMax Demonstration Plant waste from the Stuttgart central market easily fermentable low-inlignocellulose low-cost biowaste 2-stage high-load digestion with microfiltration biowaste fractions which are low in lignocellulose are almost completely converted into biogas within the space of only a few days. power station biogas is purified by utilizing a membrane system used as fuel for vehicle

17 ETAMAX DEMONSTRATION PLANT Regenerative energy and nutrients from vegetable waste and microalgae

18 Determination of availability of organic wastes Quantity and quality of wet biowastes with small content of lignocellulose 768,000 t/a biowastes have been identified in Germany Corresponds to 56 % of market losses 97 defined single locations of emergence identified (50 t/a 83,000 t/a) Single locations of emergence: 488,000 t/a of biowastes (63 %) Single locations of emergence : regional distribution according to type and quantity

19 Types of waste Organic Kitchen waste Waste from gardens/ parks (with/ without lignocellulose) Market waste Food waste from restaurants, industry Paper Wastewater (partly organic) Etc. Anorganic Glas Plastic Metal Construction waste Wastewater (e.g. nutrients, dissolved metal ions) Etc.

20 Integrated rainwater management Rainwater management gains importance in town planning in Europe Different aspects: Flood prevention during cloudbursts Pollution of surface water by dust, car brakes and tires abrasion, etc. Water courses and green areas in the city for recreational purposes and higher livability Rainwater as a resource to substitute drinking water partially Source:

21 Transfer to other regions

22 Transfer of solutions Solutions demonstrated in Germany cannot be copied one to one to other regions Adaption to frame conditions is necessary (climate, culture, regulations, economy etc.) Fraunhofer IGB has experiences with projects in Brazil China Romania Namibia

23 Projects in Brazil : Advanced wastewater treatment and evaluation of biogas production from organic waste as demonstration for viability of biogas use : Project with industrial partners with the goal to treat biogas at a WWTP for use as vehicle fuel

24 Adaptation of DEUS 21-concept in Guangzhou 80 % of drinking water for Guangzhou originates from surface water Frequent pollution of drinking water due to wastewater discharge in rivers Objective: Development of semi-decentralized water management concept for China Piloting of energy recovery from wastewater and kitchen wastes Partner: China National Electric Apparatus Research Institute CEI

25 Water concept for peri-urban areas Water treatment Rainfall Drinking water Food and income from horticulture Heat from biogas for warm water Wastewater treatment Irrigation and fertilisation (urban gardening)

26 Example: Concept for 5,000 inhabitants Concept: Based on average values. Collection and anaerobic treatment of wastewater and biowaste. Rainwater collection separately; a treatment and utilization has to be evaluated depending on climate and alternative water resources. Costs depend very much on site specific conditions. Benefits: No emission of pathogenic microorganisms nor odors => healthy environment Irrigation for rice cultivation for more than 1,000 persons Fertilization (N, P) for rice cultivation for 2,500 to 3,500 persons Biogas: Electricity supply for wastewater treatment plant covered Biogas: Water heating for around 700 persons

27 Example for 5,000 inhabitants Water treatment 219,000 m 3 /a Drinking water Rainfall variable Reduction possible by utilization of rainwater or greywater Warm water for ~ 700 cap Heat from biogas for warm water 219,000 m 3 /a Wastewater treatment Food and income from horticulture Water for rice for > 1,000 cap, nutrients for rice for ~ 3,000 cap Irrigation and fertilisation (urban gardening)

28 Operation Local operator for supervision and maintenance Treatment process fully automatic, remote control Many plants can be operated by one specialist Plants are constructed in modules, modules can be produced in large scale Potentials for complementing other renewables like solar and wind energy (storage of biogas and organic solids possible)

29 Procedure Identification of suitable location Identification of local partners Analysis of site specific characteristics, needs of users, national regulations Adaptation of concept to local situation Piloting in area with 1,000 to 5,000 inhabitants Realization by local utility/ company

30 Thank you for your attention! Thank you for your attention! Dr.-Ing. Ursula Schließmann