Source Profile And Chemical Reactivity Of Volatile Organic Compounds (VOCs) Form Vehicle Exhaust And Paints

Light-duty gasoline taxis (LDGT) and passenger cars(LDGV), heavy-duty diesel buses (HDDB) and trucks (HDDT), gasoline motorcycles (MC) and LPG scooters (LPGs), were selected for tailpipe volatile organic compounds (VOCs) samplings by using transient dynamometer and on road test combined with SUMMA canisters technology. Environmental testing chamber and field sampling were adopted to get VOCs samplings from interiro wall latex paints, furniture paints, auto refinishing spraying paints and baking paints. The samples were tested by GC-MS to analyze the concentration and species composition of VOCs.The results indicate that light-duty gasoline automobiles have higher fractions of aromatic hydrocarbons, the main aromatic hydrocarbons are toluene and xylenes. Heavy-duty diesel vehicles have higher fractions of alkanes, the main alkanes are propane, n-dodecane and n-undecane. The major compound from MC and LPGs exhaust is acetylene. VOCs exhaust from gasoline motorcycles and light-duty gasoline automobiles has a significantly higher chemical reactivity than those from heavy-duty diesel vehicles, which contribute 55% and 44% to the atmospheric chemical reactivity in Shanghai. The gasoline motorcycles and light-duty gasoline automobiles are the key pollution sources affecting city and region ambient oxidation, and the key active species of toluene, xylenes, propylene, and styrene make the greatest contribution.The average concentration of interiro wall latex paints, furniture paints, car refinishing spraying paints and baking paints are (7728.43±6265.32)μ2g·m-3, (54115.23±17576.85)μg·m-3, (73351.80±4573.47)μg·m-3 and (12770.05±123.14)μg·m-3, and aromatic hydrocarbons are the main species. The most abundant and reactive VOCs species from interiro wall latex paints, furniture paints, car refinishing spraying paints and baking paints are m&p-xylene, o-xylene and ethylbenzene, their contribution to the VOCs species composition are 72.26%,59.00%,70.97% and 60.01%, they account for 66.11%,55.47%, 64.52%,60.20% and 75.06%,65.44%,79.15%,76.00% of OH loss rate and ozone formation potential respectively.