Effects of microplastics on granular sludge: A review

Institute of Coastal Environmental Pollution Control, Key Laboratory of Marine Environment and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao, Shandong, 266100, China

^* Corresponding author’s e-mail: lifengmin@ouc.edu.cn

Abstract

Biogranules are recently regarded as promising methods with intensive density and satisfying settleability for waste treatment and resource recovery. Wastewater treatment plants (WWTP) were regarded as “sinks” for Microplastics (MPs) and amount of MPs entrapped in the sludge. MPs have been reported to harm the granular characteristics and wastewater treatment efficiency. Previous research stated that the harmful effect on granular sludge is closely associated with the sizes and concentrations of MPs. However, there is still a lack of a comprehensive summary of granular characteristics variation and further investigation of its influential mechanisms for treatment capability. This work gives informative clues for the regulation mechanisms, especially the microorganisms’ response after the exposure of MPs, and provides fundamentals for stable operation and risk control strategies using granular sludge in treating microplastics containing wastewater.