A life cycle approach to environmental assessment of wastewater and sludge treatment processes

Abstract Life cycle assessment (LCA) is a tool for determining a product or a process's environmental effects. In this study, LCA evaluates the critical sources of environmental impacts in wastewater treatment plants (WWTPs). The aim of the study is to conduct a comparative LCA of four wastewater treatment (WWT) methods: activated sludge process, sequential batch reactor, constructed wetlands, and up‐flow anaerobic sludge blanket, including the sludge treatment methods: anaerobic digestion (AD), AD with pretreatment, lime stabilization (LS), and LS with energy recovery. Environmental impacts are analysed using the IMPACT 2002+ approach and Simapro 9.1 software using the Ecoinventv3.6 database. The study result shows that the sequential batch reactor has the highest environmental effects because of its high energy consumption. Electricity used for treatment is the primary contributor to environmental impacts. The study helps in evaluating the potential environmental impacts corresponding to a WWTP and identifying the hotspots associated with the process.