1. Anaerobic Baffled Reactor 1 Martin Wafler, seecon international gmbh

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3. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info Contents 1.Concept 2.How it can optimize SSWM 3.Design principals 4.Treatment efficiency 5.Operation and maintenance 6.Applicability 7.Advantages and disadvantages 8.References 3

4. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 4 Background and working principal (adapted from U.S. EPA 2006, SASSE 1998) 1. Concept Cut-away view and longitudinal section of an ABR Source: SANIMAS (2005), MOREL & DIENER (2006) physical and biological (anaerobic) treatment of wastewater integrated sedimentation chamber for pre-treatment of wastewater alternating standing and hanging baffles wastewater passes through the sludge to move to the next compartment solid retention time (SRT) separated from hydraulic retention time (HRT) high treatment rates due to enhanced contact of incoming wastewater with residual sludge and high solid retention low sludge production

5. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 5 Construction of different toilet blocks connected to twopre-fabricated fibreglass reactors comprising a settling chamber, an aerobic baffled reactor and a final anaerobic filter unit Source: BORDA 2009 Examples 1. Concept

6. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 6 Biogas settler as settlement compartment (near completion) at Pestalozzi School, Zambia Source: http://www.germantoilet.org/ Examples 1. Concept

7. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 7 The ABR under construction, down pipes and perforated slabs to support filter media in the Anaerobic Filter (AF) sections, pouring ABR’s concrete slab at Pestalozzi School, Zambia Source: http://www.germantoilet.org/ Examples 1. Concept

8. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 8 ABR (part of DEWATS) at Adarsh Vidyaprasarak Sanstha’s College of Arts & Commerce, India Source: N. Zimmermann Examples 1. Concept

9. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 9 ABR (part of DEWATS) at Sunga Wastewater Treatment Plant, Kathmandu, Nepal Source: N. Zimmermann Examples 1. Concept

10. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 10 2. How it can optimize SSWM treatment of all wastewater (grey-, black- and/or industrial wastewater) that it is fit (after secondary treatment) for reuse and/or safe disposal allows for recovery of biogas, which can be used as a substitute to e.g. LPG or fuel wood in cooking

11. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 11 3. Design principals ABRs start with settling chamber for larger solids and impurities (SASSE 1998) followed by series of at least 2 (MOREL & DIENER 2006), sometimes up to 5 (SASSE 1998) up- flow chambers Hydraulic Retention Time (HRT) is relatively short and varies from only a few hours up to two or three days (FOXON et al. 2004; MOREL & DIENER 2006; TILLEY et al. 2008) up-flow velocity is the most crucial parameter for dimensioning, especially with high hydraulic loading. It should not exceed 2.0 m/h (SASSE 1998; MOREL & DIENER 2006). organic load <3 kg COD/m 3 /day. Higher loading-rates are possible with higher temperature and for easily degradable substrates (SASSE 1998)

12. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 12 4. Treatment efficiency Treatment performance of ABRs is in the range of (SASSE 1998; MOREL & DIENER 2006; BORDA 2008) Chemical Oxygen Demand (COD) removal: 65% to 90%, Biological Oxygen Demand (BOD) removal: 70% to 95%, Total Suspended Solids (TSS) removal: up to 90% (SINGH 2008) Pathogen reduction: low Superior to BOD-removal (30% to 50%) of conventional septic tank (UNEP 2004).

13. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 13 5. Operation and maintenance inoculate („seed“) ABR with active anaerobic sludge from e.g. septic tank to speed up start-phase allow bacteria to multiply, by starting with 1 / 4 of daily flow, and then increasing loading rates over 3 months long start-up time  do not use ABRs when need for treatment is immediate check for water-tightness regularly and monitor scum and sludge levels remove sludge every 1 to 3 years (preferably by vacuum truck or gulper to avoid that humans get in direct contact with sludge) leave some active sludge in each compartment to maintain stable treatment process take care of advanced treatment and/or safe disposal of sludge Source: adapted from SASSE 1998, TILLEY et al. 2008, EAWAG/SANDEC 2008

14. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 14 Use of “straight handle” (left) and “Z-handle” (right) brushes for cleaning of down-ward pipes Source: K.P. Pravinjith 5. Operation and maintenance Examples

15. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 15 Measuring sludge levels Source: K.P. Pravinjith 5. Operation and maintenance Examples

16. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 16 6. Applicability be installed in every type of climate, although efficiency is affected in colder climates (TILLEY et al. 2008) suited for household level or for small neighbourhood as DEWATS (Decentralized Wastewater Treatment System) (EAWAG/SANDEC 2008) suited for industrial wastewaters be designed for daily inflows in a range of some m 3 /day up to several hundreds of m 3 /day (FOXON et al. 2004; TILLEY et al. 2008) in general, installed underground and therefore appropriate for areas where land is limited been pre-fabricated from e.g. fibreglass and used as final step for emergency sanitations (BORDA 2009)

17. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 17 Disadvantages: needs expert design long start-up phase needs strategy for faecal sludge management effluent requires secondary treatment and/or appropriate discharge clear design guidelines are not available yet low reduction of pathogens Advantages: extremely stable to hydraulic shock loads high treatment performance simple to construct and operate no electrical requirements low capital and operating costs, depending on economy of scale low sludge generation biogas can be recovered 7. Advantages and disadvantages

18. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 18 8. References BORDA (2009): EmSan - Emergency Sanitation. An innovative & rapidly installable solution to improve hygiene and health in emergency situations (Concept Note). Bremen: Bremen Overseas Research and Development Association (BORDA) EAWAG/SANDEC (2008): Sanitation Systems and Technologies. Lecture Notes. (=Sandec Training Tool 1.0, Module 4). Duebendorf: Swiss Federal Institute of Aquatic Science (EAWAG), Department of Water and Sanitation in Developing Countries (SANDEC) FOXON, K.M., PILLAY, S., LALBAHADUR, T., RODDA, N., HOLDER, F., BUCKLEY, C.A. (2004): The anaerobic baffled reactor (ABR)- An appropriate technology for on-site sanitation. In=Water SA Vol. 30 No. 5 (Special edition) MOREL A., DIENER S. 2006. Greywater Management in Low and Middle-Income Countries. Review of different treatment systems for households or neighbourhoods. Duebendorf: Swiss Federal Institute of Aquatic Science and Technology (Eawag). SANIMAS (2005): Informed Choice Catalogue. PPT-Presentation. BORDA and USAID SASSE, L. (1998): DEWATS Decentralised Wastewater Treatment in Developing Countries. Bremen: Bremen Overseas Research and Development Association (BORDA)

19. Anaerobic Baffled Reactor Find this presentation and more on: www.sswm.info.www.sswm.info 19 8. References SINGH, S., HABERLA, R., MOOG, O., SHRESTA, R.R., SHRESTA, P., SHRESTA, R. (2009): Performance of an anaerobic baffled reactor and hybrid constructed wetland treating high-strength wastewater in Nepal- A model for DEWATS. In: Ecological Engineering 35. 654-660 TILLEY, E., LUETHI, C., MOREL, A., ZURBRUEGG, C., SCHERTENLEIB, R. (2008): Compendium of Sanitation Systems and Technologies. Duebendorf and Geneva: Swiss Federal Institute of Aquatic Science (EAWAG) & Water Supply and Sanitation Collaborative Council (WSSCC) U.S. EPA (2006): Emerging Technologies for Biosolids Management. (=EPA 832-R-06-005). United States Environmental Protection Agency, Office of Wastewater Management

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