Overview Training Blocks

Transcription

1 Overview Training Blocks 1st Block: Decentralized WWT Systems (10:30 11:30) Definition of decentralized wastewater management in Germany and in Jordan Technologies for decentralized wastewater treatment 2 nd Block: Exercise: Decentralized WWT City Sanitation Planning (11:30 12:30) 3 rd Training Block: Organization of Decentralized WWT (13:15-14:45) Operational/business models for decentralized wastewater management Financing of decentralized wastewater management Operation and maintenance of decentralized wastewater treatment systems Decentralized WWTS, T. Reckerzügl,

2 Decentralised wastewater treatment systems 1 st Block Thorsten Reckerzügl, BORDA, Training financed by GIZ - BMZ

3 1st Training Block: Decentralized WWT Systems Definition of decentralized wastewater management in Germany and in Jordan Technologies for decentralized wastewater treatment Decentralized WWTS, T. Reckerzügl,

4 Ad text by clicking Decentralized WWTS, T. Reckerzügl,

5 Size structure of wastewater treatment facility operators in Germany 2010 Ad text by clicking (without DWWT) Decentralized WWTS, T. Reckerzügl,

6 German Wastewater Ordinance, Annex 1 Size classification COD BOD 5 NH 4- N N total P total (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) < pe < pe < pe < pe 5 > pe pe population equivalents Decentralized WWTS, T. Reckerzügl,

7 Decentralised WWT in Germany No clear definition of decentralized WWT exist in Germany (smooth transition). Common understanding: Decentralized WWT exist where single houses or some neighboring houses have an individual WWTS (normally no pubic sewer) WWTS s operated by a municipality can be understood as semicentralized or centralized system depending on the size. WWTS operated by bigger municipalities and by multiple municipalities can be classified as centralized systems decentralized semi-centralized centralized single houses - housing clusters - settlements municipality - multiple municipalities Decentralized WWTS, T. Reckerzügl,

8 Def. small sewerage treatment plant Small sewage treatment plants for WWT below 50 population equivalent (pe). They are commonly applied in individual houses, small villages etc. where connection to large municipal WWTS is not possible for technical, legal or financial reasons A whole range of technical solutions from simple, cheap to expensive high-tech solutions exists For a long time small sewage treatment plants have not been a standard solution in Germany Understanding changed in the last 20 years. It is now more common to consider DWWT where the right framework conditions exist Decentralized WWTS, T. Reckerzügl,

9 Conclusion Decentralised WWT in Germany For a long time centralised treatment systems (96% coverage) have been in favour of decentralised solutions (3% coverage). Central WWT very sophisticated with high coverage and discharge standards. But Germanys existing sewerage systems has evolved in a period of 150 to 200 years. Investment cost are very high. Replication on a short term would not be feasible. It can be questioned whether a lot of these centralised systems especially in rural settings are the most cost efficient and sustainable solution. Views have changed meanwhile and decentralised systems are more accepted. But also in future they will probably play a minor role since centralised system coverage is already very high. Decentralized WWTS, T. Reckerzügl,

10 Titel der Präsentation/Name des Autors/Datum

11 Decentralised WWT in Jordan What is the status of decentralized WWT in Jordan? What is the current way forward? What is different to the situation on Germany? Demo Site Fuhais, Jordan Source: UFZ Leipzig Decentralsied WWTS, T. Reckerzügl,

12 Jordan National Framework for decentralized WWT Strong National Framework for decentralized treatment of domestic WW exists Decentralized WWT has been identified and is promoted as sustainable solution for rural and suburban communities It has been identified that a strict framework is required to assure effectiveness and sustainability of the sector Decentralized WWT is understood as a complementary approach to centralized WWT in rural and suburban settings Under this conditions Decentralized WWT are seen as more cost effective, reliable, resource efficient, environmental friendly, and equal convenient Strong emphasize on groundwater protection and freshwater substitution (reuse & recharge of aquifers) Decentralsied WWTS, T. Reckerzügl,

13 Jordan's National Implementation Committee (NICE) and framework topics Source: Effective Decentralized Wastewater Policy, MWI & NICE, 2015 Decentralsied WWTS, T. Reckerzügl,

14 NICE framework topics Groundwater Protection: (a) contamination hotspots, (b) WW mgt. in groundwater protection zones Technology Selection: 25 technical modules are listed and procedure for multi criteria analysis is proposed Urban Planning: (a) enforce structured planning. (b) integrate WW planning Participatory Planning: CLUES (Community-Led Urban Environmental Sanitation Planning) Economic Feasibility: ALLOWS (Assessment of Local Lowest Cost wastewater solutions Standards & Monitoring: Requirements < 500 pe and between 500 and 5000 are different; Standards vary depending on discharge option, multi barrier approach for irrigation is proposed Operation & Maintenance: Technical and Institutional Challenges are identified and Operator models are summarized Decentralsied WWTS, T. Reckerzügl,

15 Jordan's three categories for Decentralized WWT Source: Effective Decentralized Wastewater Policy, MWI & NICE, 2015 Decentralsied WWTS, T. Reckerzügl,

16 Discharge standards for WWTS of 501 to 5000 pe Source: Effective Decentralized Wastewater Policy, MWI & NICE, 2015 Decentralsied WWTS, T. Reckerzügl,

17 Discharge standards for WWTS of 50 to 500 pe Source: Effective Decentralized Wastewater Policy, MWI & NICE, 2015 Decentralsied WWTS, T. Reckerzügl,

18 Discharge standards for WWTS of 5 to 49 pe Standards equal to 50 to 500 pe discharge standard; except for TSS standard Secondary biological treatment compulsory Decentralsied WWTS, T. Reckerzügl,

19 Conclusion Decentralised WWT in Jordan Very comprehensive and innovative framework for decentralized WWT exist in Jordan If this can be put into practice on a large scale, Jordan has a very good practice example for complementary approaches of centralized and decentralized WWT on national level. For successful implementation of this framework an emphasize should be put on sustainable finance, performance monitoring, operator models and O&M, as well as user awareness and willingness to contribute. Decentralsied WWTS, T. Reckerzügl,

20 Comparison between Decentralized and Centralized Systems Centralized High capital costs (especially of sewer lines) Energy intensive (especially where pumping is required) Requires skilled, fulltime man power System failure affects the entire settlement Centralized and therefore more complex for O&M Treatment costs may be lesser than DEWATS Low social control Decentralsied WWTS, T. Reckerzügl, Decentralized Shallow sewers reduce overall costs considerably Almost no electrical energy is required Less skilled man power required Effects of system failure is localized Sustainability (less risky, easier reuse) Easy to add units/scale up Also require proper management and O&M Chance for TAP high 20

21 Systems choice & framework conditions Whether a centralized, a semi centralized decentralized clustered or a completely decentralized system is the best choice depends on framework conditions (mostly similar to points from Jordan's Decentralized WW policy): Framework conditions Economy Safety Environment/ Natural resources Operation & Maintenance Social Legislation Relevant factors Settlement structure, discharge standards Health, environmental safety, resource efficiency, disaster risk (flood, drought) Groundwater, ecosystems, GHG, space availability WW composition (variation), HR, finances, accessibility, electricity Cultural acceptance, experiences, participation Effluent values, monitoring schemes Titel der Präsentation/Name des Autors/Datum

22 Multi criteria analysis for technology choice Source: Effective Decentralized Wastewater Policy, MWI & NICE, 2015 Titel der Präsentation/Name des Autors/Datum

23 Summer of key issues for DWWT Key issues for decentralization in municipal wastewater treatment, Bernal, Restrepo, 2012 Titel der Präsentation/Name des Autors/Datum

24 SDG will have substantial influence on WW policy and practice Titel der Präsentation/Name des Autors/Datum

25 SDG s require a more holistic and complex approach on water & sanitation Other relevant agreements: UN Climate Change Conference, COP 21 Sendai Framework for Disaster Risk Reduction Conf. on Financing Developm. Adis Abbeba Habitat III, Quito Titel der Präsentation/Name des Autors/Datum

26 1st Training Block: Decentralized WWT Systems Definition of decentralized wastewater management in Germany and in Jordan Technologies for decentralized wastewater treatment Titel der Präsentation/Name des Autors/Datum

27 DEWATS- Combination of Treatment systems Wastewater Treatment Systems (DEWATS) sedimentation pond biogas digester Sedimentation septic tank Anaerobic digestion anaerobic filter anaerobic baffled reactor planted gravel filter Aerobic and facultative decomposition Post treatment aerobic-facultative ponds and aerobic polishing ponds Other systems such as UASB, sequencing batch reactors, rotating discs, activated sludge reactors, etc. do currently not belong to DEWATS

28 Septic Tank Primary treatment Anaerobic treatment unit (no oxygen) Biogas (methane and carbon dioxide) formed due to the anaerobic digestion of settled organic matter in the biogas settler Treatment efficiency 25% to 40% organic matter Biogas Raw sewage Scum partially treated wastewater Sludge Sludge

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30 Characteristics of Septic Tanks Kind of treatment: sedimentation, sludge stabilisation, CODrem 20-50% Type of wastewater: domestic and others with settleable solids Advantages: simple, durable, underground, area required: 0,5m²/m³ wwpd Disadvantages: only pre-treatment, effluent not odourless

31 Imhoff-Tank Sedimentation Protection against upflow of sludge particles Fermentation of bottom sludge cross section longitudinal section Cross Section Inflow Outflow Imhoff Tank Longitudinal Section Floatation outside funnel flow tank 1 scum Sedimentation inside funnel liquid 3 2 sludge

32 Imhoff-Tank before placing the cover DEWATS Treatment Systems.

33 Characteristics of Imhoff-Tanks Kind of Treatment: Sedimentation, sludge stabilisation, COD rem 20-50% Type of wastewater: Domestic and others with settleable solids Advantages: Simple, durable, underground, odourless effluent, area required: 0,5m²/m³ wwpd Disadvantages: Less simple than septic tank, needs very regular desludging

34 Anaerobic Baffled Reactor Secondary treatment Anaerobic treatment unit (no oxygen) Activated sludge formation at the bottom of each chamber Treatment efficiency 75% - 85% organic matter Biogas part. treated wastewater from settler Gas Gas partially treated wastewater Activated Sludge

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36 Characteristics of Anaerobic Baffled Reactors Kind of Treatment: Anaerobic degradation of suspended and dissolved solids, COD rem 60-90% Type of wastewater: Pre-settled domestic & strong industrial wastewater of narrow COD/BOD ratio Advantages: Simple, reliable and durable, high efficiency, underground, area required: 1 m²/m³ wwpd Disadvantages: Larger space during construction, less efficient with weak wastewater, longer time for maturation

37 Principle of the Anaerobic Filter Sedimentation/floatation of solids Anaerobic digestion of suspended and dissolved matter inside the filter Anaerobic digestion (fermentation) of bottom sludge gas manhole inflow scum outflow sludge sedimentation tank filter units

38 Different packing materials

39 Characteristics of Anaerobic Filters kind of treatment: anaerobic degradation of suspended and dissolved solids, COD rem 65-85% Type of wastewater: pre-settled domestic and industrial wastewater of narrow COD/BOD ratio Advantages: simple and durable if well constructed, high treatment efficiency, underground, area required: 1 m²/m³ wwpd Disadvantages: costly in construction because of filter material, clogging possible, effluent smells slightly

40 Principle of the Vertical Filter submerged for equal distribution of wastewater through flush charging oxygen follows the percolating wastewater by vacuum oxygen is available for decomposition during resting time plants keep filter surface porous plants keep filter surface porous waste water flooded with wastewater fine sand O 2 O 2 O 2 O 2 coarse sand O 2 O 2 O 2 O 2 O 2 coarse gravel ventilated channel

41 Principle of the Horizontal Filter Continuous oxygen supply to the upper layers only Anaerob-facultative conditions in the lower layers Roots of plants provide favourable environment for bacteria diversity O 2 O 2 O 2 O 2 internal water level inflow manhole upper sand layer central outlet shaft final outlet cross distribution trench filled with rocks main filter body filled with coars gravel cross collection trench filled with rocks perforated pipe connected to swivel pipe for adjustable height

42 Horizontal filter and polishing pond for a bungalow (Auroville, Tamil Nadu, India, CSR) DEWATS Treatment Systems.

43 Characteristics of Horizontal Gravel Filters Kind of treatment: Aerobic-facultative-anaerobic degradation of dissolved and fine suspended solids,cod rem 60-95% Type of wastewater: Suitable for pre-treated domestic and weak industrial wastewater Advantages: High treatment efficiency when properly designed and constructed, pleasant landscaping possible, no wastewater above ground, no nuisance of odour Disadvantages: Large permanent space, costly, difficult construction, experienced supervision required in the beginning, area required: 30m²/m³ wwpd

44 Principle of Treatment Ponds

45 Treatment Ponds Aerobic-facultative pond at a rice mill (SIITRAT, Delhi)

46 Characteristics of Anaerobic Ponds Kind of treatment: sedimentation, anaerobic degradation, sludge stabilisation, COD rem 50-70% Adequacy: strong and medium industrial wastewater Maintenance: regular removal of scum and aquatic plants, every 2 to 5 years: removal of sludge Advantages: simple in construction, flexible degree of treatment, little maintenance, no electrical energy and chemicals required Disadvantages: occupies open land, can be stinky, difficult mosquito control, area required: 4m²/m³ wwpd

47 Caracteristic of Aerobic Ponds Kind of treatment: aerobic-facultative degradation, pathogen reduction, COD rem 60-95% Adequacy: weak, pre-treated domestic and industrial wastewater Maintenance: regular removal of scum and aquatic plants, every 2 to 5 years: removal of sludge Advantages: simple in construction, reliable if properly designed, high pathogen removal rate, fish farming possible, no electrical energy and chemicals required Disadvantages: large permanent space requirement, mosquitoes and odour can become a nuisance if undersized, algae can increase effluent BOD, area required: 25m²/m³ wwpd

48 BODin CODin BODout CODout

49 Byproducts of the process & re-use Treated Water Biogas Sludge Irrigation Cooking Sludge Drying Gardening Heating Horticulture Flushing Lighting

50 Closing the loop Sources of Wastewater Toilet Laundry Use of treated WW for Gardening & Flushing Use of Sludge for Gardening Kitchen Use of residues for Biogas

51 DEWATS- Combination of Treatment systems Wastewater Treatment Systems (DEWATS) sedimentation pond biogas digester Sedimentation septic tank Anaerobic digestion anaerobic filter anaerobic baffled reactor planted gravel filter Aerobic and facultative decomposition Post treatment aerobic-facultative ponds and aerobic polishing ponds Other systems such as UASB, sequencing batch reactors, rotating discs, activated sludge reactors, etc. do currently not belong to DEWATS

52 52 DEWATS Applications at Aravind Eye Hospital Chennai, India DEWATS Aravind Eye Hospital, India

53 Titel der Präsentation/Name des Autors/Datum Source: Effective Decentralized Wastewater Policy, MWI & NICE, 2015

54 Further Information on Decentralised WWT Decentralized Wastewater Treatment Systems (DEWATS) and Sanitation in Developing Countries A Practical Guide CLUES Guideline ( Domain1/Abteilungen/sandec/schwerpunkte/sesp/CLUES/ CLUES_Guidelines.pdf) Compendium of Sanitation Systems and Technologies, EAWAG/ Sandec; content/uploads/2016/06/compendium-sanitation- Systems-and-Technologies.pdf SWWM online-compendium; MOOC EAWAG/ SANDEC: e.g. Planning & Design of Sanitation Systems and Technologies, Decentralsied WWTS, T. Reckerzügl,

55 Thank you very much! water, sanitation, energy: essential public services for all. Thorsten Reckerzügl Regional Advisor West & Central Asia Phone Decentralized WWTS, T. Reckerzügl,