A comprehensive analysis on the source-exposure and diffusion rule of VOCs for end-life vehicles dismantling activities

Abstract

In recent years, the rapid development of technology has posed significant challenges to the waste management practices of the retired vehicle industry. How to minimize the environmental impact during the recycle process of scrap vehicle has emerged as a prevalent and pressing concern. This study employed statistical analysis and positive matrix factorization (PMF) model to assess the origin of Volatile Organic Compounds (VOCs) at a scrap vehicle dismantling location situated in China. The quantification of potential hazards to human health arising from identified sources was achieved through the integration of source characteristics with exposure risk assessment. In addition, fluent simulation was employed to examine the spatiotemporal dispersion of the pollutant concentration field and velocity profile. The findings of the study revealed that the activities of parts cutting, disassembling air conditioning and refined dismantling were responsible for 89.98 %, 84.36 %, and 78.63 % of the total air pollution accumulation, respectively. Additionally, it should be noted that the aforementioned sources accounted for 59.40 %, 18.44 %, and 4.86 % of the aggregate non-cancer risk. The cumulative cancer risk was determined to be the disassembling air conditioning process, with a contribution of 82.71 %. Meanwhile, the average concentration of VOC in soil around the disassembling air conditioning area is 8.4 times higher than the background value. The simulation revealed that pollutants were primarily dispersed within the factory at a height ranging from 0.75 m to 2 m, which corresponds to the human respiratory zone and the concentration of pollutants in the vehicle cutting area was observed to exceed normal levels by over 10 times. These findings of this study may serve as a foundation for improving of environmental protection measures of industrialization.