Deterioration of single-use biodegradable plastics in high-humidity air and freshwaters over one year: Significant disparities in surface physicochemical characteristics and degradation rates

Lingling Hu; Linlin He; Li Cai; Yumeng Wang; Gang Wu; Daoyong Zhang; Xiangliang Pan; Yu-Zhong Wang

doi:10.1016/j.jhazmat.2023.133170

Deterioration of single-use biodegradable plastics in high-humidity air and freshwaters over one year: Significant disparities in surface physicochemical characteristics and degradation rates

J Hazard Mater. 2024 Mar 5:465:133170. doi: 10.1016/j.jhazmat.2023.133170. Epub 2023 Dec 7.

Authors

Lingling Hu¹, Linlin He², Li Cai³, Yumeng Wang², Gang Wu⁴, Daoyong Zhang², Xiangliang Pan⁵, Yu-Zhong Wang⁶

Affiliations

¹ College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry, Sichuan University, Chengdu 610064, China; Shaoxing Research Institute, Zhejiang University of Technology, Shaoxing 312000, China.
² College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
³ College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
⁴ The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry, Sichuan University, Chengdu 610064, China. Electronic address: gangwu@scu.edu.cn.
⁵ College of Environment, Zhejiang University of Technology, Hangzhou 310014, China. Electronic address: panxl@zjut.edu.cn.
⁶ The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, College of Chemistry, Sichuan University, Chengdu 610064, China.

PMID: 38064942
DOI: 10.1016/j.jhazmat.2023.133170

Abstract

More single-use plastics are accumulating in the environment, and likewise biodegradable plastics (BPs), which are being vigorously promoted, cannot escape the fate. Currently, studies on the actual degradation of BPs in open-air and freshwaters are underrepresented despite they are potentially headmost leakage and contamination sites for disposable BPs. Herein, we compared the degradation behavior of six BP materials and non-degradable polypropylene (PP) plastics over a 1-year in situ suspension in the high-humidity air, a eutrophic river, and an oligotrophic lake. Moreover, a 3-months laboratory incubation was performed to detect the release of dissolved organic carbon (DOC) from BPs. In both air and freshwaters, poly(p-dioxanone) (PPDO) degraded significantly while PP and polylactic acid (PLA) showed no signs of degradation. The average degradation rates of three poly(butylene adipate-co-terephthalate) (PBAT)-based films varied: 100% in river, 55% in lake, and 10% in air. In addition to PLA, surface chemical groups, hydrophilicity, and thermal stability of BPs changed, and microplastics were found on their surfaces. Correspondingly, BPs with faster degradation rates released relatively higher amounts of DOC. Environmental microbial and chemical characteristics may contribute to differences in BP degradation besides polymer specificity. Altogether, our results indicate the need for appropriate monitoring of BPs.

Keywords: Biodegradable plastics; Degradation; Dissolved organic carbon; Freshwater; Microplastic.