Using a life cycle assessment methodology for the analysis of two - PowerPoint PPT Presentation

Using a life cycle assessment methodology for the analysis of two treatment systems of food-processing industry wastewaters L. Maya-Altamira* , A.Baun*, M.Hauschild** and J.E.Schmidt* *Institute of Environment & Resources, DTU **Department of Manufacturing Engineering and Management, DTU

The problem � FPI wastewaters conventionally treated in municipal Activated Sludge (AS) Systems in Denmark. � FPI ww introduce high organic loads: higher consumptions (oxygen, electricity, ancillaries) & higher emissions (sludge). � Alternative: introduce a pre-treatment unit to cope with high loads. � Criteria needed: Evaluate technologies by environmental & technical considerations. � The effect of wastewater composition assessed.

The need To have a flexible tool to quantify the inputs & outputs that are relevant for the life cycle assessment of wastewater treatment systems for food-processing industry streams. Aggregated in a set of Represented by two mature indicators that assess technical technologies: Activated Sludge & environmental performance & Anaerobic Tank Reactor Effect of switching ww stream

The assessment � Focus on: a. System’s use stage. b. Effect of individual streams. � Functional unit: 1 volumetric Person Equivalent (P.E.) = 0.2 m 3 /d.

System boundaries Input Ancillaries & Vector electricity BACKGROUND SYSTEM: Generic models: Fish meals Input Effluents wastewaters Vector Databases & literature data. Trace materials, predict process’ requirements & emissions. FOREGROUND SYSTEM: Process’ Pet food specific models: Efficiencies & Input Effluents wastewaters consumptions dependent on ww Vector composition & volume. Predict process’ requirements, emissions, & efficiencies. Waste

System boundaries Ancillaries & Wastewater electricity streams Influent Discharge Mesophilic Anaerobic Renewable Denitrification Energy Denitrification Production Energy Nitrification Production Nitrification Renewable District Ancillary S econdary Heating Products S ettler Production Production Fertiliser Production Dewatering Pasteurisation Agricultural spread Waste Effluent Inputs/outputs of foreground system were modeled & aggregated 1 day after a steady-state operation was achieved.

Scenarios Fish Fish meals meals FOREGROUND SYSTEM: FOREGROUND SYSTEM: summer summer Activated sludge plant Anaerobic digestion + AS plant Fish Fish meals meals FOREGROUND SYSTEM: FOREGROUND SYSTEM: winter winter Activated sludge plant Anaerobic digestion + AS plant Pet food Pet food FOREGROUND SYSTEM: FOREGROUND SYSTEM: non-pre non-pre Activated sludge plant Anaerobic digestion + AS plant Pet food Pet food FOREGROUND SYSTEM: FOREGROUND SYSTEM: pretreated pretreated Activated sludge plant Anaerobic digestion + AS plant

Influent input to system Influent content (kg d-1 PE-1) Fish summer Fish winter Pet pre TAN Pet non pre COD 0.00 0.25 0.50 0.75 1.00 Influent content (COD/TAN ratio) Fish summer Fish winter Pet pre Pet non pre 0 5 10 15

LCIA – Normalized Ressource Consumption (EDIP 97) Resources consumption 1,2E+03 1,0E+03 Zinc Nickel 8,0E+02 Natural gas mPE WDK04 Manganese Lignite 6,0E+02 Iron Hard coal 4,0E+02 Crude oil Copper Aluminum 2,0E+02 0,0E+00 Pet Non pre Pet Non pre Pet Pre Fish Winter Summer Pet Pre Fish Winter Summer Fish Fish Resources consumption 12 Activated sludge Anaerobic + AS SCENARIOS Zinc 10 Nickel Natural gas Manganese 8 Lignite mPE WDK04 Iron 6 Hard coal Crude oil Copper 4 Aluminum 2 0 Pet Non pre Pet Pre Fish Winter Fish Summer Anaerobic + AS SCENARIOS

LCIA – Normalized Environmental Impacts (EDIP 97) Environmental Impacts 70 60 Photochemical oxidant (low NOx) Ozone depletion 50 Nutrient enrichment Global warming (100 years) mPE WDK94 40 EDIP Human toxicity water EDIP Human toxicity soil 30 EDIP Human toxicity air EDIP ecotox water chronic 20 EDIP ecotox water acute EDIP ecotox soil cronic 10 Acidification 0 Pet Non pre Pet Pre Summer Pet Non pre Pet Pre Summer Fish Winter Fish Winter Fish Fish Environmental Impacts Activated sludge Anaerobic + AS Photochemical oxidant (low NOx) SCENARIOS 2,0 Ozone depletion 1,8 Nutrient enrichment 1,5 Global warming (100 years) EDIP Human toxicity water 1,3 mPE WDK94 EDIP Human toxicity soil 1,0 EDIP Human toxicity air 0,8 EDIP ecotox water chronic EDIP ecotox water acute 0,5 EDIP ecotox soil cronic 0,3 Acidification 0,0 Pet Non pre Pet Pre Fish Winter Fish Summer Anaerobic + AS SCENARIOS

LCI indicators Energy indicators AS Fish Summer AS Fish Winter AS Pet Pre AS Pet Non pre Electricity consumption AS+AD Fish pausterisation (kWh d-1 PE-1) Summer Methane produced (kg d-1 PE-1) AS+AD Fish Winter Ancillary oxygen consumed (kg d- AS+AD Pet 1 PE-1) Pre Energy balance_foreground: AS+AD Pet Consumption - Production (kWh Non pre d-1 PE-1) -5 0 5 10 15

LCI indicators Removal efficiencies AS+AD Fish summer AS+AD Fish winter TAN Removal AS+AD Pet pre Efficiency AS+AD Pet non pre COD Removal Efficiency AS Fish summer TSS Removal AS Fish winter Efficiency AS Pet pre AS Pet non pre 0% 20% 40% 60% 80% 100%

Conclusions � Energy related LCI indicators exerted the greatest influence on the systems assessed. � AS plants caused the greatest LC Ressource Consumptions & Environmental Impacts. � Anaerobic digestion as an alternative for pre-treatment unit. � Pasteurisation of sludge prior disposal (fertiliser) is critical in the assessment. � The removal of N from the wastewater is overcome by the nutrient enrichment caused by the power production processes at the activated sludge scenarios. � Differences in ww compositions affected the LCA of ww treatment systems, particularly for AS & AD systems. � This flexible tool can help on the LCA of wastewater treatment systems of FPI ww. � Important to integrate technical indicators in the LCA of such ww treatment systems. � Important to aggregate inventory data with sufficient level of detail for scenario analysis of FPI ww in a LCA context.

Thanks to the National Minister of Science & Technology of Mexico for its funding to this project and to Arovit Pet Food & Fiske Fiskerness Industries for providing the wastewater samples.

Thanks for your attention ! Any question?

Modeling References � Henze et al. (1987) Activated sludge model No.1, IWAQ Scientific and Technical Report No.1, London, UK. � Batstone et al. (2002) Anaerobic digestion model No.1, IWA Scientific and Technical Report No.13, London, UK. � Copp J.B. (2002) The COST Simulation Benchmark: Description and simulator manual, COST Actions 624 & 682 Report, COST European Cooperation in the development of Science and Technology. � Copp et al.(2003) Towards an ASM1-ADM1 state variable interface for plant-wide wastewater treatment modeling. 76th Annual WEF Conference and Exposition, Oct.11-15, Los Angeles USA. � Vanrolleghem et al.(1996) Integration of wastewater treatment plant design and operation-a systematic approach using cost functions, Water Science and Technology 34(3-4), 159-171. � Hauschild M. & Wenzel H.(1998) Environmental Assessment of Products, Volume 2, Scientific Background, Chapman & Hall.