De Meester, Steven

Dewulf, Jo

Sfez, Sophie

Taelman, Sue Ellen

Van Den Hende, Sofie

English

Ghent University Academic Bibliography

Environmental Sustainability Assessment of a Microalgae Raceway Pond Treating Wastewater from a Recirculating Aquaculture System From Upscaling to System IntegrationSophie Sfez(a), Sofie Van Den Hende(b), Sue Ellen Taelman(a), Steven De 4th International Congress on Sustainability Science & Engineering26-29 May 2015Sustainable Pathways for Algal Bioenergy        Meester(a), Jo Dewulf(a)(a) Department of Sustainable Organic Chemistry and Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium(b) Laboratory for Industrial Water and Eco-Technology (LIWET), Faculty of Bioscience Engineering, Ghent University, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, BelgiumIntroductionEnAlgae: INTERREG IVB North West Strategic Initiative (03/2011 – 06/2015)9 pilot scale algae cultivation sites (micro- and macroalgae)Sustainable Pathways for Algal Bioenergy        • In Roeselare, Belgium: Algae-based wastewater treatment plant, treating wastewater from a pikeperch recirculating aquaculture systems (RAS)Aquaculture: fast growing sector competing for freshwater resourcesRASs: promising option to mitigate the environmental footprint of aquaculture systemsIntroductionSettling tankBackwash Backwash supernatantBiofiltersUVO2Recirculating aquaculture systemAlgae-based wastewater treatment system Sustainable Pathways for Algal Bioenergy        Fish sludgewastewaterFish ponds Drum filtersWaterAnaerobic digestionThe MaB-floc technology tested in 2013 in Belgium at pilot scale to treat pikeperch aquaculture wastewater from the Aquaculture Research Center of Inagro (Belgium)As they grow, MaB-flocs need to be harvested, delivering a new source of biomass: valorisation as shrimp feed and anaerobic digestion were tested at pilot scaleMaB-flocs: bioflocculating consortium of bacteria and microalgaeIntroduction Industry needs insights to know which direction to takeSustainable Pathways for Algal Bioenergy        Goal of the studyGoal 1: Assess the environmental footprint of a pilot MaB-floc SBR treating pikeperch culture WW and identify its improvement potentialGoal 2: Forecast the most sustainable valorisation pathway for MaB-flocs in the framework of an integrated aquaculture waste treatment system at industrial scalePilot MaB-floc SBR treating pikeperch wastewater (real case)Studied MaB-floc based WWT plantsMaB-floc liquorBackwash supernatantElectricitySupernatantFlue gasLandSunlightNaturalgasHeatMaB-floc raceway pondTostirring pumpsSettling tankElectricity1 pondArea: 12 m2Volume: 28 m3Flow: 2.59 m3 day-1Sustainable Pathways for Algal Bioenergy        Effluent waterMaB-floc liquorVan Den Hende 2014Pilot MaB-floc SBR treating pikeperch wastewater (real case)Hypothetical up-scaled cases (1000 m3 of WW treated per day):L: linearly up-scaled MaB-floc plantStudied MaB-floc based WWT plants41 pondsArea: 245 m2 pond-1Volume: 98 m3 pond-1Flow: 24.5 m3 day-1 pond-150 m 5 m ElectricityFlue gasSunlightNatural gasHeatSupernatantMaB-flocraceway pondTo stirring pumpsBlowerSustainable Pathways for Algal Bioenergy        41 reactors = 1ha of cultivationEffluentWaterLandSettling tankElectricityMaB-floc liquorPilot MaB-floc SBR treating pikeperch wastewater (real case)Hypothetical up-scaled cases (1000 m3 of WW treated per day):L: linearly up-scaled MaB-floc plantS: linearly up-scaled MaB-floc plant with improved stirring systemStudied MaB-floc based WWT plantsSustainable Pathways for Algal Bioenergy        Propeller pump22 W m-2Paddle wheel 5.1 W m-2Pilot MaB-floc SBR treating pikeperch wastewater (real case)Hypothetical up-scaled cases (1000 m3 of WW treated per day):L: linearly up-scaled MaB-floc plantS: linearly up-scaled MaB-floc plant with improved stirring systemE: linearly up-scaled MaB-floc plant with Belgian electricity mix replaced by 100% wind energyStudied MaB-floc based WWT plantsSustainable Pathways for Algal Bioenergy        Pilot MaB-floc SBR treating pikeperch wastewater (real case)Hypothetical up-scaled cases (1000 m3 of WW treated per day):L: linearly up-scaled MaB-floc plantS: linearly up-scaled MaB-floc plant with improved stirring systemE: linearly up-scaled MaB-floc plant with Belgian electricity mix replaced by 100% wind energyM: linearly up-scaled MaB-floc plant with MaB-floc productivity Studied MaB-floc based WWT plantsSustainable Pathways for Algal Bioenergy        improved by 30%Valorisation of MaB-flocs as shrimp feedStudied integrated systemBackwash wastewaterHeatTreated backwash supernatant released in the sewage systemDigestateElectricityHeatValorisation as shrimp feedFish sludge DigesterMaize silageShrimp feedDrying Soil conditionerRaceway pondsMaB-floc liquor Dewatering CHPBiogas Electricity to the gridPikeperch RAS Settling MillingThree scenarios are compared:Sustainable Pathways for Algal Bioenergy        Valorisation as biogasSoil conditionerMaB-floc liquorBackwash wastewaterHeatTreated backwash supernatant released in the sewage systemFish sludgeMaize silageDigester BiogasDigestateRaceway ponds Dewatering CHP Electricityto the gridPikeperch RAS SettlingValorisation of MaB-flocs as biogasThree scenarios are compared:Valorisation of MaB-flocs as shrimp feedValorisation of MaB-flocs as biogasBaseline scenarioStudied integrated systemBackwash wastewaterBackwash supernatant released in the sewage systemElectricityHeatPikeperch RASFish sludgeSettlingMaize silageBiogasElectricity to the gridDigester CHPSustainable Pathways for Algal Bioenergy        Digestate Soil conditionerHeat2 MaB-flocs plants are integrated: Plant L (linearly up-scaled plant) Plant SEM (plant L with the 3 improvements implemented50 m 5 m 41 reactors = 1ha of cultivationElectricityEffluentWaterFlue gasLandSunlightNatural gasHeatSettling tankElectricitySupernatantMaB-flocraceway pondTo stirring pumpsMaB-floc liquorBlower50 m 5 m 41 reactors = 1ha of cultivationElectricityEffluentWaterFlue gasLandSunlightNatural gasHeatSettling tankElectricitySupernatantMaB-flocraceway pondTo stirring pumpsMaB-floc liquorBlower+ + +Env. Sustainability AnalysisFunctional unitLife Cycle Assessment (LCA), ISO standards 14040 & 14044  Goal and scope definitionInterpretationGoal 1: comparison of the 4 MaB-floc based WWTPGoal 2: SA of the integration of MaB-floc based WWTP in an aquaculture systemProduction of 1 kg TSS MaB-floc liquorTreatment of 1 m3of wastewaterSyst. boundaries Cradle-to-gateSustainable Pathways for Algal Bioenergy        Inventory analysisImpact assessmentInterpretationForeground systemPilot: site dataUp-scaled: pilot data + literatureData from up-scaled plant + ecoinvent v 2.2 + literatureBackground systemecoinvent v 2.2 + literatureResource consumption (CEENE 2013)  resource efficiency analysisGlobal warming potential (IPCC 2007)  air emission efficiency analysisMarine and freshwater eutrophication (ReCiPe 2013)  water emission efficiency analysisLCA results: environmental sustainability of the MaB-floc based WWTPResource footprint (CEENE results)50100150200250300350400450ex,CEENEkg-1MaB-floc TSSTotal CEENE: 848 MJ kg-1 MaB-floc TSSSustainable Pathways for Algal Bioenergy        0P L S E M P L S E M P L S E M P L S E M P L S E M P L S E M P L S E MLand resource Fossil fuels Metal ores Minerals Nuclear energy Water resources Abiotic renewable resourcesMJex,CEENEPilotSMElectricity consumption - stirring pumps Electricity consumption - other pumpsElectricity consumption - flue gas blower Heating of the pondDirect Land occupation InfrastructureDirect phosphorus emissions to water Direct nitrogen emissions to waterLCA results: environmental sustainability of the MaB-floc based WWTPResource footprint (CEENE results)50100150200250300350400450ex,CEENEkg-1MaB-floc TSSex,CEENEkg-1MaB-floc TSS-69%-77%Total CEENE plant L: 278 MJ kg-1 MaB-floc TSSSustainable Pathways for Algal Bioenergy        0P L S E M P L S E M P L S E M P L S E M P L S E M P L S E M P L S E MLand resource Fossil fuels Metal ores Minerals Nuclear energy Water resources Abiotic renewable resourcesMJex,CEENEMJex,CEENEPilotSMElectricity consumption - stirring pumps Electricity consumption - other pumpsElectricity consumption - flue gas blower Heating of the pondDirect Land occupation InfrastructureDirect phosphorus emissions to water Direct nitrogen emissions to waterLCA results: environmental sustainability of the MaB-floc based WWTPIPCC 2007 - Climate changeRe CiPe 2013 - Marine eutrophicationRe CiPe 2013 - Freshwater eutrophication4,E-036,E-038,E-031,E-021,E-021,E-02kg-1MaB-floc TSS4,E-036,E-038,E-031,E-021,E-021,E-022,E-02-1 MaB-floc TSS1015202530eq kg-1MaB-floc TSSkg-1MaB-floc TSS-1 MaB-floc TSSeq kg-1MaB-floc TSS67% 85% 91% 28% 34% 36% 67% 90% 97% 75%Sustainable Pathways for Algal Bioenergy        PilotSMElectricity consumption - stirring pumps Electricity consumption - other pumpsElectricity consumption - flue gas blower Heating of the pondDirect Land occupation InfrastructureDirect phosphorus emissions to water Direct nitrogen emissions to water0,E+002,E-03Pilot L S Ekg Peqkg0,E+002,E-03Pilot L S Ekg Neqkg-05Pilot L S E Mkg CO2 eq kgkg Peqkgkg Neqkg-kg CO2 eq kgLCA results: environmental sustainability of the Integrated systemsBackwash wastewaterBackwash wastewaterBackwash supernatant released in the sewage systemDigestateElectricityHeatPikeperch RASFish sludgeSettlingMaize silageSoil conditionerTreated backwash supernatant released in the sewage systemValorisation as shrimp feedShrimp feedDrying Baseline scenario Raceway pondsMaB-floc liquor Dewatering HeatBiogasElectricity to the gridScenario 1 - valorisation of MaB-flocs as shrimp feedPikeperch RAS Settling MillingDigester CHPSustainable Pathways for Algal Bioenergy        Valorisation as biogasSoil conditionerMaB-floc liquorBackwash wastewaterHeatHeatDigestateElectricityHeatFish sludge DigesterMaize silageSoil conditionerTreated backwash supernatant released in the sewage systemFish sludgeMaize silageDigester BiogasDigestateRaceway ponds Dewatering CHPCHPBiogas Electricity to the gridElectricityto the gridScenario 2 - valorisation of MaB-flocs as biogasPikeperch RAS SettlingLCA results: environmental sustainability of the Integrated systemsResource footprint1- 133% - 101%Sustainable Pathways for Algal Bioenergy        Left bar: Right bar: Avoided processes1 CEENE results without abiotic renewable resourcesLCA results: environmental sustainability of the Integrated systemsFreshwater eutrophication (ReCiPe 2013)Marine eutrophication (ReCiPe 2013)Carbon footprint(IPCC 2007)Sustainable Pathways for Algal Bioenergy        Left bar: Right bar: Avoided processesConclusionMaB-floc technology: stirring has the highest contribution to most impact categoriesIntegrated aquaculture waste treatment system:• Potential to compete with the baseline scenario and contribute to a sustainable connection of the water-food-energy nexus in the aquaculture sectorSustainable Pathways for Algal Bioenergy        • Valorizing MaB-flocs into shrimp feed: overall more sustainable than into biogasFuture research:• Improvement of LCA with more complete data on nutrient cycle (measurements needed)• Focus on the improvement of the energy efficiency of the system, rather than of MaB-flocs productivityBottleneck: EU legislationThank you!Sophie.Sfez@UGent.be+32 (0) 9 264 99 27 Sustainable Pathways for Algal Bioenergy        

Environmental sustainability assessment of a microalgae raceway pond treating wastewater from a recirculating aquaculture system: from upscaling to system integration

                1.To study the improvement potential of the MaB-floc SBR raceway pond technology: - Data collection from a pilot MaB-floc raceway pond (28 m2) treating backwash supernatant from a pikeperch RAS in Belgium - Design of 4 up-scaled plants (industrial scale):  L: linear up-scaling (41 ponds; 245 m2 each)  S: plant L with propeller pumps replaced by more efficient paddle wheels  E: plant L with Belgian electricity supply mix replaced by wind power  M: plant L with a MaB-floc productivity increased by 30%   2.To study the valorisation of MaB-flocs in an integrated system - Definition of 3 integrated scenarios - Integration of 2 up-scaled plants: L (waste treatment system UpL) and SEM (combining plants S, E and M: waste treatment system UpSEM)    Life Cycle Assessment (LCA): freshwater eutrophication potential, carbon and resource footprint (ISO 14040 and 14044)  Introduction       Forecasting the environmental sustainability of a microalgae raceway pond treating aquaculture wastewater: from pilot plant to system integration at industrial scale Sophie Sfez1, Sofie Van Den Hende2, Sue Ellen Taelman1, Steven De Meester1, Jo Dewulf 1 1Department of Sustainable Organic Chemistry and Technology (EnVOC), Faculty of Bioscience Engineering, Ghent University 2Laboratory for Industrial Water and Eco-Technology (LIWET), Faculty of Bioscience Engineering, Ghent University  Contact: sophie.sfez@ugent.be Department of Sustainable Organic Chemistry and Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium Algae Around the World Symposium, Cambridge, United Kingdom This work was funded by the INTERREG IVB NWE program, the Flemish Government and Province West-Flanders within the project Energetic Algae (EnAlgae) www.enalgae.eu     Operation principle of a MaB-floc raceway pond with considered input and output 1CEENE: Cumulative Exergy Extraction from the Natural Environment (Dewulf et al. 2007) 2Only improvements S and E are analyzed in the MaB-floc raceway pond for this impact category  Functional unit: treatment of 1 m3 of aquaculture backwash water supernatant  Recirculating aquaculture systems (RAS) produce nutrient-rich effluents which need to be treated:  - Fish sludge: treatment by anaerobic digestion is an attractive option (Mirzoyan et al., 2010) - Backwash water supernatant: innovative microalgal bacterial floc sequencing batch reactor (MaB-floc SBR) technology (Van Den Hende et al., 2014a) is a promising way to avoid costly mechanical aeration of conventional activated sludge systems   Harvested MaB-flocs can be valorized as shrimp feed or as biogas (Van Den Hende et al. 2014b, 2014c)  Switching from linear fish aquaculture and separated aquaculture sludge and wastewater treatment to an integrated MaB-floc-based aquaculture waste treatment system could be a key strategy to mitigate the environmental footprint of the aquaculture sector    How can the environmental sustainability of existing MaB-floc technology be improved? How should MaB-flocs be valorized when the technology is implemented in an aquaculture waste treatment system? Functional unit: production of 1 kg MaB-floc TSS  Pond stirring has the highest contribution in all impact categories  Up-scaling reduces the resource footprint, carbon footprint and freshwater eutrophication by 66%, 65% and 71%, respectively  Replacing fossil fuels by wind power reduces the most the environmental impact of the raceway pond, followed by using a more efficient stirring system   Valorisation of MaB-flocs in the framework of an integrated aquaculture waste treatment system  Scenario 1 and 2 are only competitive with the baseline scenario if the three improvement options (S, E, M) are implemented  Valorizing MaB-flocs into shrimp feed is overall a preferable option over biogas from an environmental point of view  Resource footprint (CEENE1 2014) Freshwater eutrophication (ReCiPe 2013) Carbon footprint  (IPCC 2007) Resource footprint (CEENE 2014) Freshwater eutrophication (ReCiPe 2013) Carbon footprint (IPCC 2007) PilotElectricity consumption - stirring pumpsElectricity consumption - other pumpsElectricity consumption - flue gas blowerHeating of the pondDirect Land occupationInfrastructureDirect phosphorus emissions to waterDirect nitrogen emissions to water02004006008001.000Pilot L S E M0,E+002,E-034,E-036,E-038,E-031,E-021,E-021,E-02Pilot L S E051015202530Pilot L S E MMJ ex,CEENEkg-1MaB-floc kg P eq kg-1MaB-floc TSSkg CO2 eq kg-1MaB-floc   The improvement potential of the system is high, mainly because the energy efficiency of the raceway pond stirring system can be highly improved   Valorisation of MaB-flocs as shrimp feed is overall more sustainable than as biogas from an environmental point of view    To improve the energy efficiency of the raceway pond, more efficient stirring systems should be tested and the pond shape could be optimized   To improve the LCA, GHG emissions from the MaB-floc raceway pond should be measured Improvement of the environmental sustainability of the MaB-floc raceway pond Phosphorus emissionNitrogen emissionAnaerobic digestionShrimp feed productionAlgae-based wastewater treatment plantMaB-flocs dewateringWheat flour (shrimp feed production)Compost production (AD)Heat production from boiler (AD)Electricity from the grid (AD)Net impactRight bar:Left bar:Avoided  processes-2,E-04-1,E-040,E+001,E-042,E-043,E-044,E-045,E-046,E-047,E-048,E-04kg P eq m-3treated waterBaselinescenarioScenario 1 Scenario 2UpL UpSE UpL UpSE-1-0,500,511,52kg CO2eq m-3treated waterBaselinescenarioScenario 1 Scenario 2UpL UpLUpSEM UpSEM-30-20-100102030405060MJex,CEENEm-3treated waterUpL UpSEM UpL UpSEMScenario 1 Scenario 2BaselinescenarioUpL UpL UpSEMUpSEMWithout Abiotic renewable resourcesWithout Abiotic renewable resources Material and methods  Results Conclusion and future outlooks Valorisation as biogas Soil conditioner MaB-floc liquor Backwash wastewater Backwash wastewater Backwash wastewater Heat Backwash supernatant released in the sewage system Digestate Electricity Heat Fish sludge Settling Maize silage Soil conditioner Treated backwash supernatant released in the sewage system Electricity Valorisation as shrimp feed Digester Shrimp feed Drying  Soil conditioner Treated backwash supernatant released in the sewage system Fish sludge Maize silage Digester  Biogas Baseline scenario  Digestate  Raceway ponds  Raceway ponds  Dewatering  MaB-floc liquor Dewatering  Heat Biogas CHP Electricity to the grid Electricity to the grid Electricity to the grid Scenario 1 - valorisation of MaB-flocs as shrimp feed Pikeperch RAS Settling Milling Scenario 2 - valorisation of MaB-flocs as biogas Digester CHP Pikeperch RAS Settling Pikeperch RAS CHP Fish sludge Maize silage Heat Digestate Biogas Heat MaB-flocs liquor Effluent water Electricity Supernatant Flue gas Land Sunlight Natural gas Heat MaB-floc raceway pond To stirring pumps Electricity MaB-floc liquor Backwash supernatant Settling tank 

Forecasting the environmental sustainability of a microalgae raceway pond treating aquaculture wastewater : from pilot plant to system integration at industrial scale

https://biblio.ugent.be/publication/7196042/file/7196058.pdf

Environmental sustainability assessment of a microalgae raceway pond treating wastewater from a recirculating aquaculture system: from upscaling to system integration

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Ghent University Academic Bibliography

Ghent University Academic Bibliography