Insight into the effect of UVC-based advanced oxidation processes on the interaction of typical microplastics and their derived disinfection byproducts during disinfection

Juanjuan Yao; Hanyang Qian; Zhihao Yan; Xiong Zhao; Naiyun Gao; Zhi Zhang

doi:10.1016/j.jhazmat.2024.134597

Insight into the effect of UVC-based advanced oxidation processes on the interaction of typical microplastics and their derived disinfection byproducts during disinfection

J Hazard Mater. 2024 Jul 5:472:134597. doi: 10.1016/j.jhazmat.2024.134597. Epub 2024 May 14.

Authors

Juanjuan Yao¹, Hanyang Qian², Zhihao Yan², Xiong Zhao², Naiyun Gao³, Zhi Zhang²

Affiliations

¹ Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 40045, China. Electronic address: yaojuanjuan@cqu.edu.cn.
² Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 40045, China.
³ State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.

PMID: 38759281
DOI: 10.1016/j.jhazmat.2024.134597

Abstract

The 10 µm polystyrene and polyethylene-terephthalate microplastics (MPs), prevalent in finished drink water, were employed to investigate the effect of normal dosage UVC-based advanced-oxidation-processes (UVC-AOPs) on the interaction between MPs and their derived disinfection-byproducts (DBPs) during subsequent chlorination-disinfection, in the presence of Br^-, for the first time. The results indicated that UVC/H₂O₂ caused higher leaching of microplastic-derived dissolved-organic-matter (MP-DOM), with smaller and narrower molecular-weight-distribution than UVC and UVC/peroxymonosulfate (UVC/PMS). The trihalomethanes (as dominant DBPs) molar-formation-potentials (THMs-MFPs) for MP-DOM leached in different UVC-AOPs followed the order of UVC/H₂O₂>UVC/PMS>UVC. The adsorption of formed THMs, especially Br-THMs, back on MPs was observed in all MPs suspensions with or without UVC-AOPs pre-treatment. The Cl-THMs adsorption by MPs is more sensitive to UVC-AOPs than Br-THMs. The adsorption experiments showed that UVC-AOPs reduce the capacity but increase the rate of THMs adsorption by MPs, suggesting the halogen and hydrogen bonding forces governed the THMs adsorption rate while hydrophobic interaction determines their adsorption capacity. The UVC-AOPs pre-treatment sharply increased the total yield of THMs via both indirectly inducing MP-DOM leaching and directly increasing the THMs-MFPs of MPs by oxidation. 21.36-41.96% of formed THMs adsorbed back on the UVC-AOPs-pretreated MPs, which might increase the toxicity of MPs.

Keywords: Adsorption mechanism; DBPs; MP-DOM; Microplastics; UVC-AOPs.