The environmental assessment of tertiary treatment technologies for wastewater reuse by considering LCA uncertainty

Abstract

Tertiary treatment methods can result in severe environmental impacts that should be taken into consideration when deciding about the best system for wastewater reuse applications beside technical and economic issues. Life cycle assessment (LCA) commonly is used for evaluating the environmental impacts of these methods. Given the importance of uncertainty analysis, it is still an uncommon practice in LCA researches in recent years, especially those focused on tertiary wastewater treatment technologies (TWWTTs). Therefore, the main purpose of this study is to investigate the parameter and input data uncertainty in LCA of TWWTTs. Considering huge amount of data collected for LCA from different sources with various precision, there is high uncertainty in obtained LCA results that could affect the ranking of different methods based on their environmental impacts. The Monte-Carlo based method is used for uncertainty analysis of LCA and it is investigated how it can affect the final ranking of tertiary treatment methods based on their environmental impacts. In present study, LCA is used to study the environmental impacts of 22 tertiary treatment systems used for further treatment of effluent of South of Tehran wastewater treatment plant (WWTP) located at the south of Tehran, Iran. The treated wastewater of this WWTP is planned to be used for different purposes including landscape irrigation and groundwater recharge as well as industrial and non-potable household (toilet flushing) usages. Among the 22 tertiary treatment systems, the best system for each application was chosen, based on the LCA results and the uncertainty of LCA.