66-Assessment of Municipal Wastewater Treatment Systems Using Life Cycle Assessment Approach.

Abstract

With increasing environmental concerns and rapid growth of wastewater in domestic as well as in industrial sector, there is an urgent need to treat the wastewater with lower environmental footprints. Different types of treatment technologies are practice to treat large amount of wastewaters. It was found that there is the research gap of appropriate comparison of wastewater treatment technologies, hence this study was undertaken. Present study investigates the performance of four municipal sewage treatment plants (STP) in India based on different technologies. Environmental impacts of selected STPs were calculated and compared through Life Cycle Assessment tool using CML 2 baseline methodology and Eco-invent database. Only operation and maintenance phase of each technology used in secondary treatment was considered during the study. Four impact categories including, energy consumption, Global Warming Potential, Acidification Potential and Eutrophication Potential were considered. During assessment, four technologies of sewage treatment, namely, Constructed Wetland (CW), Activated Sludge Process (ASP), Extended Aeration (EA) and Submerged Aerobic Fixed Film Reactor (SAFF) were selected. Among the selected STPs, the CWs based STP has found in owing negligible energy consumption and negative Global Warming Potential (GWP) due to carbon sequestration capacity of macrophyte (Canna indica), than other treatment technologies. SAFF reactor and EA process shows almost similar emission impact for all impact categories. The main contributors of environmental impacts of STPs are emission allied with electricity production required for operation of plant.