| Summary: | 碩士 === 國立中山大學 === 環境工程研究所 === 103 === With the increasing odor petition cases year by year, problems caused by odor emissions from various sources have become an important issue of air pollution control. This study used hypochlorc acid (HOCl) solution or ozonated air in series with alkaline hydrogen peroxide (H2O2) solution (pH in the range of 12.0-12.5 and 0.3 % H2O2) in a two-stage scrubbing process to remove volatile organic compounds (VOCs) and the associated odors vented from thermal-setting operations of textiles. Test gases were obtained by heating wasted oil gathered from waste gas scrubbers. A system consisting of two laboratory scrubbing bottles both with a liquid volume of 600 mL ranged in series was used and the test gas was injected into the system at a rate of 1 L/min at 25oC.
Results indicate that HOCl solutions with available chlorine 30-200 ppm at a pH of 6.5 were not effective for removing VOCs and odors in the test gas. However, an operation with 5 ppm ozone in the influent gas to the scrubbing water followed by the alkaline H2O2 solution was able to remove about 87% of the influent VOCs at a concentration of around 10 ppm (expressed as methane equivalent). Take the operation as an example, odor intensities of the influent gas could be reduced from 550,000 (expressed as dilutions to threshold) to 505. Pungent oily odor in the test gas was almost completely removed. The odor intensity (505) of the scrubbed gas meets the regulation of less than 1,000 for exhaust gas from an emission pipe with a height of lower than 18 m above ground, as set by the EPA of Taiwan. An estimations indicates that it costs around USD 0.25 (including fix cost depreciation, utilities and chemicals) for scrubbing 1,000 Nm3 of the exhaust gas.
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