Characterization of volatile organic compounds (VOCs) in emissions from industrial sources

Abstract

In this research, observation based methods were used to characterize a wide range of VOCs in emissions from PRD industries. Corresponding VOC source signatures from emissions of particular industrial work processes or activities were obtained, and then used to further analyze the PRD ambient air composition. This research comprises three VOC field studies. Impact of industrial emissions on the PRD region was firstly examined. The year-2000 field VOC data preliminarily gave VOC compositions of industrial, industrial-urban and industrial-suburban atmosphere of the PRD, and showed the impact on the local air quality due to the spread of industrial activities from urban area to suburban and rural areas. Toluene was the most abundant VOC. Instead of vehicular emission, industrial solvent usage contributed to the high atmospheric toluene levels. Also, some samples showed that the adjacent industrial activities greatly affected the neighbourhood atmospheric VOCs. In the 2003 study, the impact of the transported industrial pollutants on Zhuhai, a south coastal city, was then investigated. By the classification of three different characteristic prevailing wind directions in three sampling days, the result showed that strong polluted sources from inland PRD cities and upwind industrial areas greatly affected the whole Zhuhai city, because strong north wind frequently transported polluted air masses from the upwind PRD industrial regions, carrying enriched toluene, dichloromethane and other industrial organic pollutants to Zhuhai. In addition, mild east wind could transport polluted plume from a suburban-industrial area to the downwind suburban sampling site. Under the influence of clean sea air, local vehicular emission became the major anthropogenic source in the downtown and roadside microenvironment. The 2005 VOC study was conducted in Qingxi, an inland PRD town in Dongguan. VOC source signatures of different work processes of electronic industry and printing industry were collected, and then used in explaining the general impact of industrial activities. The rooftop TVOC of the printing factory was about 20 times higher than that of the electronic factory. Most of the abundant VOCs collected on the rooftop of the electronic factory were produced by the corresponding work processes inside the factory. In the case of the printing factory, toluene contributed more than half of the total VOCs in three examined work processes. The role of respective industries on local ambient atmosphere was also discussed in the study.