Aging mechanism of microplastics with UV irradiation and its effects on the adsorption of heavy metals

Ruofan Mao; Mengfan Lang; Xiaoqin Yu; Renren Wu; Xiaomei Yang; Xuetao Guo

doi:10.1016/j.jhazmat.2020.122515

Aging mechanism of microplastics with UV irradiation and its effects on the adsorption of heavy metals

J Hazard Mater. 2020 Jul 5:393:122515. doi: 10.1016/j.jhazmat.2020.122515. Epub 2020 Mar 10.

Authors

Ruofan Mao¹, Mengfan Lang¹, Xiaoqin Yu¹, Renren Wu², Xiaomei Yang³, Xuetao Guo⁴

Affiliations

¹ College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China.
² State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control, South China Institute of Environmental Sciences, MEE, Guangzhou 510655, PR China. Electronic address: wurenren@scies.org.
³ College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
⁴ College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, 712100, China. Electronic address: guoxuetao2005@nwafu.edu.cn.

PMID: 32197203
DOI: 10.1016/j.jhazmat.2020.122515

Abstract

Microplastics are formed by the degradation of plastic wastes under the action of physicochemical mechanisms in environment, and they are becoming a new type of pollutant that is attractings global attention. However, research on the aging characteristics and mechanism of microplastics is limited. The aging mechanism of Polystyrene (PS) with UV irradiation under different conditions (air, pure water and seawater) and the effect of aging on heavy metal adsorption were studied. The results show that PS have different characteristics with UV irradiation under different conditions, and the aging of PS is the most obvious in air. Based on the 2D-COS analysis, different aging mechanisms were identified under different aging conditions, aging sequence of aged PS functional groups in air and water were clearly definited. An isothermal adsorption model shows that aging can significantly increase the adsorption of heavy metals by PS. The adsorption of heavy metals is also affected by different aging methods. Over all, a 2D-COS analysis was an effective method for understanding the aging process of PS. These results further clarify the aging mechanism of PS, and provides a theoretical basis for the assessment of environmental behavior and ecological risk when microplastics and heavy metals coexist.

Keywords: 2D-COS; Adsorption; Heavy metal; Microplastics; UV irradiation.

Publication types

Research Support, Non-U.S. Gov't