Insight into interactions between microplastics and fulvic acid: Mechanisms affected by microplastics type

Xinglei Wang; Xiaoxiao Wang; Weimin Zhu; Ling Ding; Xujun Liang; Renren Wu; Hongtao Jia; Xianfei Huang; Xuetao Guo

doi:10.1016/j.scitotenv.2023.169427

Insight into interactions between microplastics and fulvic acid: Mechanisms affected by microplastics type

Sci Total Environ. 2024 Feb 25:913:169427. doi: 10.1016/j.scitotenv.2023.169427. Epub 2023 Dec 20.

Authors

Xinglei Wang¹, Xiaoxiao Wang¹, Weimin Zhu¹, Ling Ding², Xujun Liang², Renren Wu³, Hongtao Jia⁴, Xianfei Huang⁵, Xuetao Guo⁶

Affiliations

¹ College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
² 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.
³ State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control, South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China. Electronic address: wurenren@scies.org.
⁴ College of Resources and Environment, Xinjiang Agricultural University, Urumqi 830052, China.
⁵ Guizhou Provincial Key Laboratory for Environment, Guizhou Normal University, Guiyang, Guizhou 550001, China.
⁶ 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: 38135066
DOI: 10.1016/j.scitotenv.2023.169427

Abstract

Microplastics (MPs) can interact with dissolved organic matter (DOM), a common component found in the environment. However, the effect of MPs type on its interaction with DOM has not been systematically studied. Therefore, the binding properties of different MPs with fulvic acid (FA) were explored in this study. The results showed that polypropylene (PP) and polyethylene (PE) had higher adsorption affinity for FA than polystyrene (PS) and polyvinyl chloride (PVC). The interaction between MPs and FA conformed to the pseudo-first-order model and Freundlich model (except PS). The interaction mechanisms between various MPs tested in this paper and FA are considered to be different. PP, PE and PS interacted with the aromatic structure of FA and were entrapped in the FA polymers by the carboxyl groups and CO bonds, resulting in a highly conjugated co-polymer, suggesting that oxygen-containing functional groups played a key role. However, it was assumed that the interaction between PVC and FA was more likely to be caused by hydrophobic interaction. This research will help to enhance our comprehension of the environmental behavior of MPs and their interaction with the DOM specifically.

Keywords: Fulvic acid; Microplastics; Two-dimensional correlation spectroscopy.