Microplastics as an emerging vector of Cr(VI) in water: Correlation of aging properties and adsorption behavior

Huimin You; Changlin Cao; Xiaoli Sun; Baoquan Huang; Qingrong Qian; Qinghua Chen

doi:10.1016/j.scitotenv.2023.166480

Microplastics as an emerging vector of Cr(VI) in water: Correlation of aging properties and adsorption behavior

Sci Total Environ. 2023 Dec 15:904:166480. doi: 10.1016/j.scitotenv.2023.166480. Epub 2023 Aug 22.

Authors

Huimin You¹, Changlin Cao², Xiaoli Sun², Baoquan Huang³, Qingrong Qian⁴, Qinghua Chen²

Affiliations

¹ College of Environmental and Ecology, College of Coastal and Ocean Management Institute, Xiamen University, Xiamen 361000, China; College of Environmental and Resource Sciences; College of Carbon Neutral Modern Industry; Fujian Key Laboratory of Pollution Control & Resource Reuse, Engineering Research Center of Polymer Green Recycling of Ministry of Education, Fujian Normal University, Fuzhou 350007, China.
² College of Environmental and Resource Sciences; College of Carbon Neutral Modern Industry; Fujian Key Laboratory of Pollution Control & Resource Reuse, Engineering Research Center of Polymer Green Recycling of Ministry of Education, Fujian Normal University, Fuzhou 350007, China.
³ College of Environmental and Resource Sciences; College of Carbon Neutral Modern Industry; Fujian Key Laboratory of Pollution Control & Resource Reuse, Engineering Research Center of Polymer Green Recycling of Ministry of Education, Fujian Normal University, Fuzhou 350007, China. Electronic address: qbh811@fjnu.edu.cn.
⁴ College of Environmental and Resource Sciences; College of Carbon Neutral Modern Industry; Fujian Key Laboratory of Pollution Control & Resource Reuse, Engineering Research Center of Polymer Green Recycling of Ministry of Education, Fujian Normal University, Fuzhou 350007, China. Electronic address: qrqian@fjnu.edu.cn.

PMID: 37611697
DOI: 10.1016/j.scitotenv.2023.166480

Abstract

Microplastics (MPs) are emerging contaminants with growing concerns due to their potential adverse effects on the environment. However, understanding the aging properties and adsorption behavior of MPs is still limited. In this study, we investigated the correlation between the adsorption capacity, aging stages, and aging properties of polyethylene MPs using a correlation equation. Our results revealed that the trends of O/C ratio and contact angle of polyethylene MPs with aging time were fitted to be linear under xenon lamp accelerated aging conditions. Conversely, the trends of other properties such as particle size, crystallinity, and molecular weight with time were fitted to conform to the Boltzmann equation. Moreover, the aging curve data for carbonyl index and molecular weight (M_w) perfectly matched, confirming M_w play a crucial role in verifying the aging process. Additionally, the adsorption amount of polyethylene MPs increased sharply with the increase of aging ages, reaching up to 1.850 mg/g. The adsorption data fit well to the pseudo-second-order kinetics and Langmuir model, suggesting that the adsorption process is dominated by chemisorption. The low pH and low salt concentration is beneficial to the adsorption capacity of MPs onto Cr(VI). Further, a relationship equation was established to predict adsorption risk at different aging stages. These findings provide new insights into the impact of aging on pollutants transport and the fate of MPs, enabling the prediction of adsorption risk of MPs at different aging stages in water environments.

Keywords: Adsorption; Correlation; Microplastics; Photoaging; Polyethene.