Abstract
With the acceleration of economic development and urbanization in China, sewage sludge generation has sharply increased. To maximize energy regeneration and resource recovery, it is crucial to analyze the environmental impact and sustainability of different sewage sludge recycling systems based on life cycle assessment. This study analyzed four sewage sludge recycling systems in China through life cycle assessment using the ReCipe method, namely aerobic composting, anaerobic digestion and biomass utilization, incineration, and heat utilization and using for building materials. In particular, the key pollution processes and pollutants in sewage sludge recycling systems were analyzed. The results demonstrated that aerobic composting is the most environmentally optimal scenario for reducing emissions and energy consumption. The lowest environmental impact and operating costs were achieved by making bricks and using them as building materials; this was the optimal scenario for sludge treatment and recycling. In contrast, incineration and heat utilization had the highest impact on health and marine toxicity. Anaerobic digestion and biomass utilization had the highest impact on climate change, terrestrial acidification, photochemical oxidant formation, and particulate matter formation. In the future, policy designers should prioritize building material creation for sludge treatment and recycling.
Highlights
With the rapid development of the economy and urbanization in China, municipal sewage has gradually become a huge environmental problem that needs to be urgently solved
Sewage sludge treatment has previously been considered secondary to wastewater treatment but is gradually becoming one of the most significant challenges facing municipal wastewater management worldwide, in China (Yang et al 2015)
The large quantity of sewage sludge should not be considered a heavy burden to municipal management but rather a great source of bioenergy and recovered material (Raheem et al 2018, Tyagi & Lo 2013)
Summary
With the rapid development of the economy and urbanization in China, municipal sewage has gradually become a huge environmental problem that needs to be urgently solved. From the normalization results (Fig. 4), the most obvious midpoint environmental impact category was human toxicity, followed by freshwater eutrophication, marine toxicity, and terrestrial acidification. From the perspective of CC, the environmental impact mainly comes from the use of fossil energy and the emission of CO2 (98%) during sludge incineration.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
