CHARACTERIZATION OF VOLATILE ORGANIC COMPOUNDS EMITTED FROM BIOLOGICAL DEGRADATIONS OF ORGANIC WASTE AND SEWAGE IN NORTH CHINA

Volatile organic compounds (VOCs) emitted from anaerobic biological processes of organic waste and wastewater were investigated in four sites in North China, including a biogas well of landfill, a fermentation workshop of pharmaceutical residues, an anaerobic digestion workshop of pharmaceutical wastewater, and an anaerobic digester of petrochemical wastewater. 108 VOC species were qualified and quantified by a gas chromatography-mass spectrometry system with canister sampling. Results showed that the total amounts of analyzed VOCs varied from 8503 +/- 1320 mu g/m(3) to 727 +/- 109 mu g/m(3) in summer with the order as municipal landfill > pharmaceutical residues >pharmaceutical wastewater > petrochemical wastewater. The most abundant types of VOCs in the municipal landfill were halogenated hydrocarbons (41.9%), followed by acetates (22.0%), aromatic hydrocarbons (13.0%) and alcohols (10.5%). For the pharmaceutical residues, alkenes (51.4%) dominated, followed by aromatic hydrocarbons (22.5%) and alkanes (16.0%). For the pharmaceutical wastewater, aromatic hydrocarbons (27.1%) dominated, followed by ketones (24.9%), acetates (20.71%) and halogenated hydrocarbons (11.4%). For the petrochemical wastewater, aromatic hydrocarbons were highest, accounting for 28.3% of the total species, they were followed by alkanes (25.9%), halogenated hydrocarbons (19.9%) and methyl tert-butyl ether (14.8%). These results implied that the types and levels of airborne VOCs species from the four biological degradation processes exist significant differences, which were mainly caused by the type of waste and wastewater, operational characteristics of the treatment plant, and environmental conditions. In the other hand, the reactivity of VOCs species from the four sources was also assessed by OH loss rate, due to the impact of VOCs on the production of tropospheric ozone and secondary organic aerosol (SOA).