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(W/MC257) Life Cycle Assessment of Wastewater Treatment Systems. Núñez, Yolanda1,2, del Álamo, Josué1,2, Fernández, Juan 1,2, Hidalgo, Mª Dolores1, Irusta, Ruben1,2, 1 2 ABSTRACT- Nowadays, the majority of European cities have sewage treatment plants in order to reduce water pollution. Therefore, it seems to be interesting to carry out a Life Cycle Assessment comparing the potential environmental impacts associated with different wastewater treatment scenarios based on physical-chemical pre-treatment in Spain. In this case, the purpose of this comparison is to improve the basis for possible decision-making on wastewater treatment systems. For the design and evaluation of the wastewater treatment scenarios a theoretic model was developed. Different techniques can be applied for treatment: biological techniques, as well as physical or physical-chemical techniques. All wastewater treatment scenarios are designed for an wastewater treatment plant of 100,000 population equivalents. In the inventory analysis, mass flows and environmental inputs and outputs were calculated, interpreted and presented. This comparison involve the wastewater treatment stage, anaerobic digestion of sludge, sludge transportation and sludge incineration. The impact assessment method used takes into account the energy demand, chemical consumption, potential global warming, acidification, eutrophication, photo-oxidant formation and final sludge production. The environmental impacts originated by the different scenarios are quite disparate. Our results indicate that the energy demand is significantly lower for treatment scenarios, based on physical-chemical pre-treatment, however these systems produce more final sludge after thickening and digestion. Many environmental improvements can be made within the wastewater treatment systems. This LCA results of this study might be significantly improved through increased energy efficiency and decreased the final sludge production. It would be necessary to carry out a study with data from Spanish sewage treatment plants in order to corroborate these results. Key words: Life Cycle Assessment, Wastewater treatment |
