The effect of microplastics on behaviors of chiral imidazolinone herbicides in the aquatic environment: Residue, degradation and distribution

• Published in: Journal of hazardous materials 2021-09, Vol.418, p.126176-126176, Article 126176
• Main Authors: Hu, Mingfeng, Hou, Ning, Li, Yuanfu, Liu, Yanmei, Zhang, Hui, Zeng, Dongqiang, Tan, Huihua
• Format: Article
• Language: English
• Subjects: Enantioselective Degradation and Distribution; Imidazolinone Herbicides; Microplastics; Water-sediment Microcosms
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.126176

The pollution of aquatic environments by microplastics and herbicides has become a global concern. This study was focused on imazamox, imazapic, and imazethapyr sorption to polypropylene microplastics in water. And the potential effects of microplastics on herbicide enantiomer degradation and distributions in water, sediment, and water–sediment microcosms were investigated. Adsorption experiment results indicated that herbicide sorption to microplastics involved both chemisorption and physical adsorption. Degradation experiment results indicated that microplastics could markedly increase herbicide persistence in water and sediment. Marked stereoselective degradation was not found for the three herbicides in water and sediment, but stereoselective degradation of imazapic in water containing microplastics was found. The water–sediment microcosms experiment results indicated that microplastics have significant effect on stereoselectivity degradation and distribution in water and water-sediment microcosms for imazapic, and have little effect on stereoselectivity behaviors of imazamox and imazethapyr in water-sediment systems. Furthermore, the microcosm experiment results also indicated that herbicides can partition between water and microplastics and that microplastics could affect herbicide persistence and distributions in aquatic environments. The present study provides new insights into the fate of chiral pollutants in aquatic environments containing microplastics, and contributes to understanding behaviors of herbicides and microplastics in aquatic environments. The environment behavior of co-contaminants (Microplastics and three imidazolinone herbicides) in water-sediment microcosms [Display omitted] •The adsorption behavior of herbicides onto polypropylene microplastics relied on both chemisorption and physical adsorption.•Polypropylene microplastics could adsorb herbicides by partitioning and influencing their persistence in sediment and water.•Polypropylene microplastics can affect the residues and distribution of herbicides in water–sediment microcosms.