Quantification of environmental impacts of domestic wastewater treatment using life cycle assessment: A review

Life cycle assessment (LCA) is an analytical tool used to quantify the overall environmental impacts associated with products, processes or human activities from cradle to grave. The LCA is important to determine the impact of wastewater treatment and the technologies used on human health and the environment. It performs well to find the best solutions to improve the sustainability. Therefore, it is important to review how previous studies on wastewater treatment have applied LCA. This paper presents a wide-ranging review of papers published from 1990 to 2016 that have used a range of LCA to cover the objectives, boundaries, functional units (FUs) and life cycle impact assessment(LCIA) of wastewater treatment. The analysis of the reviewed papers revealed that there are some differences in term of the FUs, system boundaries, and LCIA methods. These differences normally contribute to obtaining a few non-prosaic results. Moreover, the FUs adopted in some reviewed studies were not able to achieve the purpose of providing a reference to ensure compatibility of the results. Therefore, it is highly recommended that more attention is paid to choosing the FU in future studies. Thus, to ensure the quality and comparability of LCAs, it is very important to develop the LCA guidelines and standards and the LCIA impact categories.