RECEPTOR MODELING OF VOCS, CO, NOX, AND THC IN TAIPEI

An empirical receptor model based on Markov Chain Monte Carlo simulati on was applied to one-year measurements of eight VOCs, CO, NOx, and TH C collected in Taipei during 1993. Ambient monitoring data were measur ed at four monitoring stations in Taipei metropolitan. Among five VOC- based sources (motorcycles, catalyst passenger cars, non-catalyst pass enger cars, diesel vehicles, and gasoline vapor), non-catalyst passeng er cars had the greatest contributions to eight VOCs (53-61%; 90.0-220 .3 mu g m(-3)). Among seven sources based on CO-NOx-THC emissions (cat alyst and non-catalyst two-stroke motorcycles, four-stroke motorcycles , catalyst and non-catalyst passenger cars, diesel vehicles, and gasol ine vapor), passenger cars had the greatest contributions to NOx (50-6 3%; 0.05-0.26 mg m(-3)), motorcycles had the greatest contributions to CO (70-76%; 0.81-4.97 mg m(-3)) and gasoline vapor contributed substa ntially to THC (17-58%; 0.35-0.85 mg m(-3)). Our empirical receptor mo dels have successfully improved the estimation of source coefficients for VOCs, CO, NOx, and THC by partially solving the collinearity probl ems among various mobile source profiles. Such an improved methodology is useful for validating source inventory and managing air quality in metropolitan areas.