Source apportionment analysis of volatile organic compounds using positive matrix factorization coupled with conditional bivariate probability function in the industrial areas

Abstract

© 2020, Thai Society of Higher Eduation Institutes on Environment. All rights reserved. Ambient volatile organic compounds (VOCs) concentration data from January 2013 – December 2018 were analyzed by using the US EPA PMF (positive matrix factorization) (v5.0) to identify airborne benzene source. We further analyzed for the potential emission source of benzene by analyzed of the extent and magnitude of measured ambient benzene concentrations following the New Zealand’s air quality categories by using Conditional Bivariate Probability Function (CBPF). Results from the analysis revealed that the major contributors were mobile sources (62.80 – 44.58%), petroleum industry (15.74-43.56%) and refinery (11.86 – 21.46%). Results of CBPF analysis were agreed well with the locations of major point sources. The probability of the extent and magnitude of high level of benzene concentrations of greater than the Thailand annual ambient air quality standard (1.7µg/m3) at the receptor sites with respect to wind speed and wind directions were illustrated. It was found that these high concentrations were most likely occurred when the wind blew from South (S) to West (W), Northwest (NW) and Northeast (NE). These results confirmed that mobile source and petrochemical industry contributed as dominant sources of benzene concentrations in the communities were those located in the S-W direction from the benzene monitoring sites.