Anaerobic Reactors - chernicharo

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Anaerobic Reactors

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<ul><li><p>8th IWA Specialist Group Conference on Waste Stabilization Ponds</p><p>.</p><p>2nd Latin-American Conference on Waste Stabilization Ponds</p><p>Round TableIntegration of ponds with other systems</p><p>Belo Horizonte, April 2009</p><p>Carlos Augusto de Lemos CherncharoDepartment of Sanitary and Environmental Engineering</p><p>Federal University of Minas Gerais Belo Horizonte - Brazil</p></li><li><p>Brazilian and developing countries:</p><p> Large pieces of flat land are not always available </p><p> Enormous sanitation deficit</p><p> Shortage of financial resources</p><p> Lack of qualified operational personal</p><p> Need of low cost, sustainable and simplified wastewater treatment systems</p><p> Soil characteristics many times inappropriate for large natural systems, such as ponds and constructed wetlands</p><p> Reuse still in early stages</p></li><li><p>Based on that scenario:</p><p> Two process combinations have very interesting features:</p><p> Quality of treated effluent is mainly regulated considering discharge and receiving body standards</p><p> Compact anaerobic treatment systems can play a major role:</p><p> UASB + Polishing Ponds (PP) UASB + Trickling Filters (TF)</p><p> UASB reactor is a very good alternative </p></li><li><p>Brief background on UASB reactors</p><p>Drawbacks and possible improvements</p><p>Examples of full-scale applications</p><p>Summary</p><p>Integration with Polishing Ponds</p><p>Integration with Trickling Filters</p><p>Final remarks</p></li><li><p>Brief background on UASB reactors</p></li><li><p>Main characteristics Advantages Applicability</p><p>Large urban areas</p><p>Small decentralized </p><p>systems</p><p>Small communities</p><p>No oxygen consumption</p><p>Low sludge production</p><p>Sludge is more concentrated and easy to dewater</p><p>Biogas production</p><p>Simple to operate</p><p>Lower O&amp;M costs</p><p>Lower construction costs</p><p>Possibility of energy recovery</p><p>Anaerobic systems: general aspects</p><p>Brief background on UASB reactors</p></li><li><p>UASB Reactor</p><p> The system is self-mixed by the upflow movement of biogas bubbles and by the liquid through the reactor, allowing the contact between the organic matter and the biomass. As a result, biogas is formed.</p><p>Brief background on UASB reactors</p></li><li><p>UASB Reactor</p><p> The 3-phase separator is located in the upper part of the reactor, allowing the separation of gas, liquid and solids</p><p>Brief background on UASB reactors</p></li><li><p>UASB Reactor</p><p> The settling zone allows the exit of the clarified effluent and the return of solids (biomass) to the digestion zone, in lower part of the reactor</p><p>Brief background on UASB reactors</p></li><li><p>UASB Reactor</p><p> The UASB reactor functions, simultaneously, as a primary settler, as a biological reactor, as secondary clarifier and as sludge digester</p><p>Brief background on UASB reactors</p></li><li><p>UASB Reactor Typical configurations</p><p>Brief background on UASB reactors</p></li><li><p>Examples of full-scale applications</p></li><li><p> Location: Itabira Brazil Configuration: UASB reactors + TF</p><p> Design population: 60,000 inhabitants Design flowrate: 120 L/s (1st stage)</p><p>Itabira WWTP</p><p>Examples of full-scale applications</p></li><li><p>Itabira WWTP</p><p>Sludge withdrawal and sampling ports</p><p>Examples of full-scale applications</p></li><li><p>Itabira WWTP</p><p>Feed distribution system and 3-phase separator</p><p>Examples of full-scale applications</p></li><li><p>Itabira WWTP</p><p>Biogas flare and thermal sludge treatment device</p><p>Examples of full-scale applications</p></li><li><p> Location: Belo Horizonte Brazil Configuration: UASB reactors + TF</p><p> Design population: 1 million inhabitants Design flowrate: 1.8 m3/s (1st stage)</p><p>Ona WWTP</p><p>Examples of full-scale applications</p><p>Aerial view</p></li><li><p>Ona WWTP</p><p>Examples of full-scale applications</p><p>Aerial view</p></li><li><p>Feed distribution system (top of the reactor)</p><p>Ona WWTP</p><p>Examples of full-scale applications</p></li><li><p>Feed distribution system (bottom of the reactor)</p><p>Ona WWTP</p><p>Examples of full-scale applications</p></li><li><p>3-phase separator</p><p>Ona WWTP</p><p>Examples of full-scale applications</p></li><li><p>Biogas system</p><p>Ona WWTP</p><p>Examples of full-scale applications</p></li><li><p>Drawbacks and possible improvements</p></li><li><p>Odour generation</p><p>Most of all are possible to control, with proper designs &amp; adequate construction, operation and maintenance</p><p>Corrosion</p><p>Limited efficiency</p><p>Scum</p><p>Foam</p><p>Anaerobic systems: inherent limitations</p><p>Methane emission</p><p>Drawbacks and possible improvements</p></li><li><p>Proper materials</p><p>Proper lining</p><p>Turbulence minimization</p><p>Turbulence maximization</p><p>Corrosion</p><p>Inherent limitations: corrosion</p><p>Drawbacks and possible improvements</p></li><li><p>Liquid phase</p><p>Turbulence minimization</p><p>Aerobic post-treatment</p><p>Gaseous phase</p><p>Reactor cover</p><p>Gas collection</p><p>Gas treatment</p><p>Gas flare</p><p>Turbulence maximization</p><p>Odour</p><p>Inherent limitations: Odour</p><p>Drawbacks and possible improvements</p></li><li><p>Ongoing researches</p><p>Removal device</p><p>Treatment and final disposal</p><p>Minimize formation</p><p>The problem</p><p>Scum</p><p>Inherent limitations: Scum</p><p>Drawbacks and possible improvements</p></li><li><p>Control of household discharges</p><p>Turbulence minimization</p><p>Aerobic post-treatment</p><p>The problem</p><p>Foam</p><p>Inherent limitations: Foam</p><p>Drawbacks and possible improvements</p></li><li><p>Compliance with local guidelines ? (ex.: dilution, agricultural reuse etc.)</p><p>Post-treatment for the removal of carbonand pathogens (well established)</p><p>Improvement of anaerobic effluent quality(Ongoing research)</p><p>Post-treatment for the removal of N and P(research still needed)</p><p>Limited efficiency</p><p>Inherent limitations: Limited efficiency</p><p>Drawbacks and possible improvements</p></li><li><p>Micro-aeration inside the reactor?</p><p>Stripping outside the reactor?</p><p>Methane emission</p><p>Inherent limitations: Methane emission</p><p>Biological oxidation?</p><p>Drawbacks and possible improvements</p><p>The problem</p></li><li><p>UASB technology: summary</p><p> Consolidated technology in many warm-climate regions</p><p> Great advantages and broad application, but operational limitations still exist</p><p> Further expansion and wider application can be significantly hindered if design and operationaldrawbacks are not solved</p><p>Drawbacks and possible improvements</p></li><li><p>Integration with Polishing Ponds</p></li><li><p>UASB reactor + Polishing Ponds: typical flowsheet</p><p>Integration with Polishing Ponds</p></li><li><p> Location: Centre for Research and Training on Sanitation UFMG/COPASA Design population: 250 inhabitants Design flowrate: 1.6 m3/h</p><p>UASB reactor + Polishing Ponds: Experimental Units</p><p>Integration with Polishing Ponds</p></li><li><p>180 mg/L</p><p>60 mg/L</p><p>COD</p><p>TSS</p><p>Integration with Polishing Ponds</p><p>Performance regarding organic matter and solids</p><p>Operational conditions:</p><p>- HRT: 10 to 13 days</p><p>- H: 0.60 to 0.80 m</p></li><li><p>20 mg/L</p><p>Operational conditions:</p><p>- HRT: 10 to 13 days</p><p>- H: 0.60 to 0.80 m</p><p>103 MPN/100 mL</p><p>NH3</p><p>E. coli</p><p>Performance regarding ammonia and E. coli</p><p>Integration with Polishing Ponds</p></li><li><p>UASB + PP system: summary</p><p> Area required is large: 2 3 m2/inhabitant</p><p> Total HRT is lower than in most natural treatment systems</p><p> UASB reactor: main unit responsible for organic matter removal</p><p> Ponds: responsible for excellent coliform and good ammonia removals</p><p> Coarse filter: decreases algal concentration, thus leading to complementary BOD and SS removal</p><p>Integration with Polishing Ponds</p></li><li><p>Integration with Trickling Filters</p></li><li><p>UASB reactor + Trickling Filter: typical flowsheet</p><p>Integration with Trickling Filters</p></li><li><p> Location: Centre for Research and Training on Sanitation UFMG/COPASA Design population: 500 inhabitants Design flowrate: 3.2 m3/h</p><p>Compact UASB + Trickling Filter System: Experimental Units</p><p>Integration with Trickling Filters</p></li><li><p>Integration with Trickling Filters</p><p>Compact UASB + Trickling Filter System: Experimental Units</p></li><li><p>Individualized compartments</p><p> Location: Centre for Research and Training on Sanitation UFMG/COPASA Design population: 400 inhabitants Design flowrate: 2.6 m3/h</p><p>Trickling Filter with different types of packing media</p><p>Integration with Trickling Filters</p></li><li><p>Full-scale UASB + TF system: Itabira Minas Gerais</p><p>Integration with Trickling Filters</p></li><li><p>Concentraes de DBO total (mg/L) - efluente UASB e decantadores FBP</p><p>UASB Escria anel DHS Condute0</p><p>10</p><p>20</p><p>30</p><p>40</p><p>50</p><p>60</p><p>70</p><p>80</p><p>90</p><p>Concentraes de SST (mg/L) - efluentes UASB e decantadores FBPs</p><p>UASB Escria anel DHS Condute0</p><p>20406080</p><p>100120140160180200220240260</p><p>Concentraes de DQO total (mg/L) - efluente UASB e decantadores</p><p>UASB Escria Anel DHS Condute0</p><p>50</p><p>100</p><p>150</p><p>200</p><p>250</p><p>300</p><p>350</p><p>400</p><p>450</p><p>60 mg/L</p><p>180 mg/L</p><p>60 mg/L</p><p>BOD COD</p><p>TSS</p><p>Integration with Trickling Filters</p><p>Performance regarding organic matter and solids</p><p>Operational conditions: Average temperature: 250C HLR: 20 m.m-2.d OLR 0.43 kgBOD.m-3.d-1</p></li><li><p>20 mg/L</p><p>Operational conditions: Average temperature: 230C HLR: 10 m.m-2.d-1 OLR 0.38 kgBOD.m-3.d-1</p><p>NH3</p><p>Integration with Trickling Filters</p><p>Performance regarding ammonia removal</p><p>20 mg/L</p><p>Operational conditions: Average temperature: 250C HLR: 10 m.m-2.d OLR 0.24 kgBOD.m-3.d-1</p><p>NH3</p></li><li><p>2 mg/L</p><p>Operational conditions: Average temperature: 230C HLR: 20 m.m-2.d-1 OLR 0.43 kgBOD.m-3.d-1</p><p>LAS</p><p>Integration with Trickling Filters</p><p>Performance regarding anionic surfactants</p><p>2 mg/L</p><p>Operational conditions: Average temperature: 250C HLR: 10 m.m-2.d OLR 0.24 kgBOD.m-3.d-1</p><p>LAS</p></li><li><p>UASB + TF system: summary</p><p> Very compact system: ~ 0.1 m2/inhabitant</p><p>Drawbacks and possible improvements</p><p> UASB reactor: main unit responsible for organic matter removal</p><p> TF: complementary BOD and SS removal</p><p> TF: poor coliform removal</p><p> TF: good ammonia removal can be accomplished, but surface area and depth should be increased</p></li><li><p>Final remarks</p></li><li><p>Critical and important aspects in the selection of alternatives for wastewater treatment in developed and developing regions</p><p>Selection criteria for developed and developing countries</p><p>Developed countries Developing countriesEfficiencyReliabilitySludge disposalLand requirementsEnvironmental impactsOperational costsConstruction costsSustainabilitySimplicity</p><p>critical Important Important criticaladapted from von Sperling, 1996</p></li><li><p>Relative comparison of UASB/PP and UASB/TF treatment methods</p><p>Treatment system</p><p>EconomySustainability</p><p>Simplicity in O&amp;M</p><p>Removal efficiencyReli-ability</p><p>Lower possibility of environmental problems</p><p>Requirements CostsBOD Nutrients Coliforms Bad odours Noise Aerosol</p><p>Insects wormsLand Energy Constr. O &amp; M</p><p>UASB + PP + +++++ ++/++++ ++++ +++++ ++++ ++++ +++ +++++ ++++ +++ +++++ +++++ ++UASB + TF ++++ ++++ +++ +++ ++++ +++ +++++ ++/+++ ++ ++++ ++ ++++ ++++ +++</p><p>+++++: most favourable +: least favourable ++++, +++, ++: intermediate grades, in decreasing order + / +++++: variable with land and soil characteristics</p><p>Both alternatives are very attractive for treating domestic wastewater in developing countries</p></li><li><p>Thanks for your attention</p></li><li><p>Scum accumulation on settling compartment</p></li><li><p>Scum accumulation inside the 3-phase separator</p></li><li><p>Waste gas </p><p>Biogas</p><p>FunB</p><p>i</p><p>o</p><p>g</p><p>a</p><p>s</p><p>:</p><p>m</p><p>i</p><p>c</p><p>r</p><p>o</p><p>-</p><p>a</p><p>e</p><p>r</p><p>a</p><p>t</p><p>i</p><p>o</p><p>n</p><p>Biogas treatent</p><p>Heat</p><p>Electricity</p><p>Cogeneration of heat and electricity</p><p>Biofiltro</p><p>H2S and CH4 control in large WWTP</p><p>Biofilter</p></li><li><p>COD balance in UASB reactors treating domestic wastewater</p><p>Best situation</p><p>Conversion to CH4 and </p><p>recovery as biogas64%</p><p>Conversion to CH4 and loss with the liquid </p><p>phase8%</p><p>Losses with the gaseous </p><p>phase5%</p><p>Used for sulfate </p><p>reduction4%</p><p>Conversion to biomass</p><p>21%</p></li><li><p>Conversion to CH4 and </p><p>recovery as biogas23%</p><p>Conversion to CH4 and loss with the liquid </p><p>phase36%</p><p>Losses with the gaseous </p><p>phase5%</p><p>Used for sulfate </p><p>reduction16%</p><p>Conversion to biomass</p><p>21%</p><p>COD balance in UASB reactors treating domestic wastewater</p><p>Worst situation</p></li><li><p>Biofiltro</p><p>Biogas FlareWaste gas</p><p>Degasified effluent</p><p>Biogas</p><p>E</p><p>f</p><p>f</p><p>l</p><p>u</p><p>e</p><p>n</p><p>t</p><p>s</p><p>a</p><p>t</p><p>u</p><p>r</p><p>a</p><p>t</p><p>e</p><p>d</p><p>w</p><p>i</p><p>t</p><p>h</p><p>C</p><p>H</p><p>4</p><p>W</p><p>a</p><p>s</p><p>t</p><p>e</p><p>g</p><p>a</p><p>s</p><p>f</p><p>r</p><p>o</p><p>m</p><p>p</p><p>r</p><p>e</p><p>l</p><p>i</p><p>m</p><p>i</p><p>n</p><p>a</p><p>r</p><p>y</p><p>t</p><p>r</p><p>e</p><p>a</p><p>t</p><p>m</p><p>e</p><p>n</p><p>t</p><p>Fun</p><p>H2S and CH4 control in small WWTP</p><p>Biofilter</p><p> 8th IWA Specialist Group Conference on Waste Stabilization Ponds.2nd Latin-American Conference on Waste Stabilization PondsRound Table Integration of ponds with other systemsSlide Number 2Slide Number 3Slide Number 4Slide Number 5Slide Number 6Slide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20Slide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Slide Number 28Slide Number 29Slide Number 30Slide Number 31Slide Number 32Slide Number 33Slide Number 34Slide Number 35Slide Number 36Slide Number 37Slide Number 38Slide Number 39Slide Number 40Slide Number 41Slide Number 42Slide Number 43Slide Number 44Slide Number 45Slide Number 46Slide Number 47Slide Number 48Slide Number 49Slide Number 50Slide Number 51Slide Number 52Slide Number 53Slide Number 54Slide Number 55Slide Number 56Slide Number 57Slide Number 58</p></li></ul>