Release of microplastics from typical rainwater facilities during aging process

Xiaoran Zhang; Chao Liu; Junfeng Liu; Ziyang Zhang; Yongwei Gong; Haiyan Li

doi:10.1016/j.scitotenv.2021.152674

Release of microplastics from typical rainwater facilities during aging process

Sci Total Environ. 2022 Mar 20:813:152674. doi: 10.1016/j.scitotenv.2021.152674. Epub 2021 Dec 29.

Authors

Xiaoran Zhang¹, Chao Liu¹, Junfeng Liu², Ziyang Zhang³, Yongwei Gong⁴, Haiyan Li⁵

Affiliations

¹ Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing 102616, China; Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing 100044, China.
² Department of Water Conservancy and Civil Engineering, Beijing Vocational College of Agriculture, Beijing 102442, China. Electronic address: liujunfeng@bvca.edu.cn.
³ Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing 100044, China.
⁴ Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing 102616, China.
⁵ Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing 100044, China. Electronic address: lihaiyan@bucea.edu.cn.

PMID: 34971679
DOI: 10.1016/j.scitotenv.2021.152674

Abstract

As the demand for urban flood prevention and drainage increases, a large number of plastic rainwater facilities are in use. Microplastics will be released inevitably into stormwater systems during aging and hydraulic scouring processes, which could cause potential pollution risk. This study simulated the release behavior of microplastics from three typical plastic rainwater facilities including a rainwater inspection well, rainwater storage module, and rainwater pipe (mainly composed of high-density polyethylene, polypropylene, and polyvinyl chloride, respectively) under the effects of aging and hydraulic scouring. After 15-45 days of UV aging and 72 h of hydraulic scouring, the surfaces of the three facilities were found to exhibit increases in roughness, cracks, folds, and cavities, with the most pronounced changes occurring in the rainwater storage module. As the aging time increased, oxygen-containing functional groups formed and led to carbon chain scission. Fourier transform infrared spectroscopy (FTIR), two-dimensional correlation spectroscopy (2D-COS) and X-ray photoelectron spectroscopy (XPS) of facility surfaces showed that the formation of oxygen-containing functional groups was an important factor affecting the release of microplastics. The amount of microplastics released from the three facilities ranged from 160 to 1905 items/g (microplastics/facilities), following in the order of rainwater inspection well > rainwater storage module > rainwater pipe. The particle size of the released microplastics ranged from 3 to 1363 μm, with 10-30 μm accounting for the greatest proportion of particles, 50.10%. The size of microplastics released from the rainwater inspection well and rainwater storage module increased with the aging degree, while the release from the rainwater pipe decreased. The release behavior depends mainly on the composition of the materials and the aging time. Thus, microplastics can be released from plastic rainwater facilities under suitable conditions. The results can be used to further evaluate microplastic pollution caused by urban rainwater facilities.

Keywords: Aging; Microplastic; Rainwater facility; Release.

MeSH terms

Environmental Monitoring
Microplastics*
Plastics
Polyethylene
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Water Pollutants, Chemical
Polyethylene