| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 87 === More public concerns have been placed on volatile organic compounds (VOC) and odor substances emitted from Public Owned Treatment Works or the municipal sewerage treatment plants. In this study, the VOC and odor substances emission rate of Min-Shen municipal sewerage treatment plant was investigated. The various VOCs and odor substances were identified with GC/MS, and the emission rates of VOC was measured using floating flux chamber which was introduced from New South Wales University, Australia. An US EPA certified TO-1 method was used for sampling the emitted VOCs as well as the odor air substances in the treatment plant.
Eight kinds of volatile organic compounds were identified. Benzene, trichloroethylene, toluene, tetrachloroethylene, ethylbenzene, and xylene aer in the category of VOCs; and dimethyl sulfide and dimethyl disulfide are classified as odor substances. Among the various VOCs emitted, toluene and tetrachloroethylene were commonly detected in every unit of Min-Shen sewerage treatment plant. Fairly high emitted concentrations were measured in the primary sedimentation tank, RBC, and aeration basin. The emission rates of benzene, ethylbenzene, toluene, and xylene decreased as unit operation proceeded from upstream unit to down stream unit, for example from primary sedimentation tank to final clarifier. Trichloroethylene and tetrachloroethylene were found to have highest emission rates in RBC and aeration basin probably because of high Henry''s transport constant and difficult to be biodegraded. The only two odor substances, dimethyl sulfide and and dimethyl disulfide, were detected in the down stream units as RBC, aeration basin, and aerobic sludge digester.
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