Spatiotemporal variations and source analysis of VOCs in the environmental air of a typical pesticide remediation site

Frontiers in Environmental Science

Environmental Science

Xuwei Li¹  Da Ding¹  Mengjie Wang¹  Shaopo Deng¹  Dengdeng Jiang¹  Wenyi Xie¹  Xuzhi Li¹  Lingya Kong¹ 

[1] Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of China, Nanjing, China;State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Nanjing, China;

关键词: volatile organic compound;    environmental air;    contribution rates;    source analysis;    emission sources;   

DOI  :  10.3389/fenvs.2023.1272836

 received in 2023-08-04, accepted in 2023-09-21,  发布年份 2023

来源: Frontiers

【 摘 要 】

As efforts to mitigate soil and groundwater pollution intensify nationwide, the incidence of volatile organic compound (VOC) contaminated sites has risen significantly. These sites exhibit continuous release and dispersion of VOCs during and after remediation/control processes, thereby adversely affecting the local environment and residents. This issue has emerged as a prominent concern in contemporary society. This study takes a representative pesticide-contaminated site as the research subject. The pollutant levels, composition, spatiotemporal distribution, and source characteristics of VOCs in the ambient air environment from 2016 to 2021 were investigated by statistical analysis, Geographic Information System (GIS) spatial interpolation, Positive Matrix Factorization (PMF) model, and characteristic ratio source. The results showed that the average mass concentration proportions of the five types of pollutants are: benzene, toluene, ethylbenzene, and xylenes (BTEX) (29.73%) > alkanes (26.85%) > oxygenated hydrocarbons (21.96%) > halogenated hydrocarbons (19.12%) > sulfides (2.35%). M-/p-xylenes and toluene were the main contributing pollutants of BTEX and appeared frequently in the lists of top three pollutant in the contribution rates at various sites. The average concentration range of VOCs inside (EA1∼EA5) and outside the site (CK1∼CK4) were 810.71–1437.24 μg/m³, and 784.47–1358.16 μg/m³, respectively. The spatial distribution and variation trend in concentrations of halogenated hydrocarbons and alkanes were similar, with both being high in the middle of the site in 2017 and high in the south in 2018, and then sharply falling to a lower level in 2019. The source analysis results showed that the main contribution sources of environmental air varied over time. There were three types of emission sources for VOCs during the monitoring periods in 2016 and 2018. The maximum contributions to total volatile organic compounds (TVOCs) in 2016 and 2018 were volatile sources of characteristic pollutants within the site (45.6%) and volatile source of fuel (70.6%), respectively. This study provides scientific evidence for the environmental management, planning, and VOCs pollution control of pesticide-contaminated sites in China.

【 授权许可】

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Copyright © 2023 Li, Ding, Xie, Li, Wang, Kong, Jiang and Deng.