Towards environmentally sustainable water management in Africa: a comprehensive review of life cycle assessment studies in water and wastewater treatment

Abstract Purpose Life cycle assessment (LCA) provides a comprehensive methodology to evaluate the environmental impacts of products, processes, and services based on the net flow of energy, materials, and emissions throughout their life cycle. This review focuses on the state of LCA in water and wastewater treatment in Africa, aiming to ascertain the extent of its implementation while synthesising the existing challenges and opportunities. Methods The articles were selected using the systematic review checklist of the standardised technique for assessing and reporting reviews of LCA. Strings of keywords were used to search for articles on the Web of Science, Scopus, and Google Scholar databases. Only original articles that assessed at least the water or wastewater treatment process using the ISO 14040/14044 LCA methodology were included. Case studies included were carried out in Africa. Results and discussion A total of 41 studies containing 131 scenarios were found. Over 68% of the studies originated from South Africa and Egypt, with a notable absence of representation from Nigeria and Tunisia. Urban wastewater treatment was assessed in 41% of the studies, 37% covered industrial, and 7% focused on domestic. In total, 15% was dedicated to water treatment. Only 32% of all studies considered the entire life cycle. The ReCiPe and CML were the most popular impact assessment methods. Biosolids and nutrient recovery were covered in 23% and 9% of the studies, respectively. Global warming potential was the most influential impact category, and electricity generation from fossil fuels was the major contributor to adverse environmental impacts. Conclusions The review emphasises the need for increased data acquisition and storage, renewable energy use, and material recovery to offset environmental impacts in the water and wastewater sectors. It highlights the importance of integrating LCA into engineering design, engaging stakeholders in LCA, and establishing performance standards for green innovations. Future research and policy development to promote sustainable treatment practices are advocated.