Biological processes have been proven to be economical and effective for control of volatile organic compounds (VOCs) with concentration of <1,000 mg C/m3 and VOCs such as toluene, xylenes, and dichloromethane(DCM) have been shown to be biodegradable. An activated sludge tank can be used as a bioscrubber for the purpose. Into the tank, an air stream is introduced through the spargers originally for aeration. Water-soluble contaminants in the air stream are absorbed into the mixed liquid and, subsequently, degraded by the microorganisms in the aeration tank.
In this study, a pilot-scale activated-sludge tank (0.4 m¡Ñ0.4 m in cross-sectional area and 3 m in water depth) was used as a bioscrubber to study the treatability of gas-borne toluene, xylenes, and DCM. Synthetic gases with the three VOCs with concentrations in the rang of 250-1000 ppm (measured as methane) were used as the test gases. Effects of volumetric aeration rate (Q/V), influent VOC concentration, and submerged liquid depth on the removal efficiency of the influent VOCs were tested.
Results show that with Q/V = 3.75-11.25 m3/m2.h, pH = 6-8, MLSS (mixed liquor suspended soilds concentration) = 1600-2800 mg/L, and submerged liquid depth D = 1.1 m, removal efficiencies were 93.1, 93.9, and 98.8%, respectively, for toluene, xylenes, and DCM. The removal efficiencies were nearly independent of the operating conditions.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0829101-190736 |
| Date | 29 August 2001 |
| Creators | Chang, Hsiao-Yu |
| Contributors | Mei-J Sya, Haung ns., Chou.ms. |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0829101-190736 |
| Rights | unrestricted, Copyright information available at source archive |
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