Recent advances in microplastic removal from drinking water by coagulation: Removal mechanisms and influencing factors

Yufeng Mao; Zuoyuan Hu; Hong Li; Huaili Zheng; Shengfa Yang; Weiwei Yu; Bingran Tang; Hao Yang; Ruixu He; Wenshu Guo; Kailai Ye; Aoguang Yang; Shixin Zhang

doi:10.1016/j.envpol.2024.123863

Recent advances in microplastic removal from drinking water by coagulation: Removal mechanisms and influencing factors

Environ Pollut. 2024 Mar 31:349:123863. doi: 10.1016/j.envpol.2024.123863. Online ahead of print.

Authors

Yufeng Mao¹, Zuoyuan Hu², Hong Li³, Huaili Zheng³, Shengfa Yang², Weiwei Yu², Bingran Tang³, Hao Yang², Ruixu He², Wenshu Guo², Kailai Ye², Aoguang Yang², Shixin Zhang⁴

Affiliations

¹ Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, China; Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing, 400044, China.
² Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, China.
³ Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing, 400044, China.
⁴ Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, China. Electronic address: zhangsx@cqjtu.edu.cn.

PMID: 38565391
DOI: 10.1016/j.envpol.2024.123863

Abstract

Microplastics (MPs) are emerging contaminants that are widely detected in drinking water and pose a potential risk to humans. Therefore, the MP removal from drinking water is a critical challenge. Recent studies have shown that MPs can be removed by coagulation. However, the coagulation removal of MPs from drinking water remains inadequately understood. Herein, the efficiency, mechanisms, and influencing factors of coagulation for removing MPs from drinking water are critically reviewed. First, the efficiency of MP removal by coagulation in drinking water treatment plants (DWTPs) and laboratories was comprehensively summarized, which indicated that coagulation plays an important role in MP removal from drinking water. The difference in removal effectiveness between the DWTPs and laboratory was mainly due to variations in treatment conditions and limitations of the detection techniques. Several dominant coagulation mechanisms for removing MPs and their research methods are thoroughly discussed. Charge neutralization is more relevant for small-sized MPs, whereas large-sized MPs are more dependent on adsorption bridging and sweeping. Furthermore, the factors influencing the efficiency of MP removal were jointly analyzed using meta-analysis and a random forest model. The meta-analysis was used to quantify the individual effects of each factor on coagulation removal efficiency by performing subgroup analysis. The random forest model quantified the relative importance of the influencing factors on removal efficiency, the results of which were ordered as follows: MPs shape > Coagulant type > Coagulant dosage > MPs concentration > MPs size > MPs type > pH. Finally, knowledge gaps and potential future directions are proposed. This review assists in the understanding of the coagulation removal of MPs, and provides novel insight into the challenges posed by MPs in drinking water.

Keywords: Coagulation; Drinking water; Influencing factors; Microplastics; Removal mechanisms.

Publication types

Review