Impacts of microplastics on organotins' photodegradation in aquatic environments

Chunzhao Chen; Ling Chen; Yang Li; Wanyi Fu; Xiaonan Shi; Jiajun Duan; Wen Zhang

doi:10.1016/j.envpol.2020.115686

Impacts of microplastics on organotins' photodegradation in aquatic environments

Environ Pollut. 2020 Dec:267:115686. doi: 10.1016/j.envpol.2020.115686. Epub 2020 Sep 18.

Authors

Chunzhao Chen¹, Ling Chen², Yang Li³, Wanyi Fu⁴, Xiaonan Shi⁵, Jiajun Duan³, Wen Zhang⁶

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA.
² State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
³ Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
⁴ John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA; Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, China.
⁵ John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA.
⁶ John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA. Electronic address: wen.zhang@njit.edu.

PMID: 33254701
DOI: 10.1016/j.envpol.2020.115686

Abstract

Microplastics are ubiquitous in natural waters and affect the environmental fate of hydrophobic organic micropollutants. This study evaluated the impacts of four microplastics, polypropylene (PP), polyethylene (PE), polystyrene (PS) and polymethyl methacrylate (PMMA), on the photodegradation of organotin compounds (OTCs) under UV₃₆₅ irradiation (2.3 ± 0.1 W m^-2). The experiments were performed by mixing PP, PE, PS or PMMA microparticles with tri-organotins in artificial seawater. The photodegradation of OTCs in microplastic suspensions was influenced by the absorptivity onto microplastics. The decomposition rate of tributyltin (TBT) in UV-irradiated PP suspensions was greater than trimethyltin (TMT) and triphenyltin (TPhT) (p < 0.01). The adsorption capacities of OTCs (e.g., TBT) on PP particle surfaces were significantly lower than those on PE surfaces (p < 0.05) but similar with those on PMMA due to the different surface areas, shapes, and surface hydrophobicity of microplastics. TBT degraded faster (9.1%) in PS than in PMMA suspension (11.2%) within 240 min, respectively. However, only less than 5.4% was photodegraded in PP suspension due to the light scattering or absorption of the large sized PP particles. This study provided new insight into the impacts of microplastics on photodegradation of micropollutants in natural waters.

Keywords: Adsorption; Hydroxyl radicals; Microplastics; Organotins; Photochemical degradation.

MeSH terms

Microplastics
Organotin Compounds*
Photolysis
Plastics
Polypropylenes
Water Pollutants, Chemical*

Substances

Microplastics
Organotin Compounds
Plastics
Polypropylenes
Water Pollutants, Chemical