Effect of microplastics on greenhouse gas and ammonia emissions during aerobic composting

Yue Sun; Xiuna Ren; Junting Pan; Zengqiang Zhang; To-Hung Tsui; Liwen Luo; Quan Wang

doi:10.1016/j.scitotenv.2020.139856

Effect of microplastics on greenhouse gas and ammonia emissions during aerobic composting

Sci Total Environ. 2020 Oct 1:737:139856. doi: 10.1016/j.scitotenv.2020.139856. Epub 2020 Jun 1.

Authors

Yue Sun¹, Xiuna Ren¹, Junting Pan², Zengqiang Zhang¹, To-Hung Tsui³, Liwen Luo³, Quan Wang⁴

Affiliations

¹ College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, PR China.
² Key Laboratory of Non-point Source Pollution of Ministry of Agricultural and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
³ Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Hong Kong.
⁴ College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, PR China. Electronic address: quanwang_1990@163.com.

PMID: 32563113
DOI: 10.1016/j.scitotenv.2020.139856

Abstract

The aim of this study was to investigate the effect of polyethylene (PE), polyvinyl chloride (PVC) and polyhydroxyalkanoate (PHA) microplastics on greenhouse gas and ammonia emissions during 60 days composting. PE, PVC and PHA microplastics were respectively mixed with the cow manure; and a treatment without microplastics was used as the control. Compared to the control, PE and PVC inhibited organic matter degradation. Conversely, PHA accelerated temperature increases and organic matter degradation. Meanwhile, PE and PHA aggravated CH₄ and NH₃ emissions by 7.9-9.1% and 20.9-33.9%, respectively. PVC decreased CH₄ and NH₃ emissions by 6.6% and 30.4%, respectively. Additionally, the N₂O emissions of the PE and PVC treatments were higher than those of the control while PHA decreased N₂O emissions by 11.8%. Furthermore, PE, PVC and PHA microplastics reduced the NO₃^--N contents and compost maturity. The results indicated that microplastics reduced compost quality while the effects of microplastics on greenhouse gases and ammonia emissions were related to their sources.

Keywords: Ammonia emission; Compost maturity; Composting; Greenhouse gas; Microplastics.