碩士 / 國立屏東科技大學 / 環境工程與科學系 / 87 / The objective of this study is to develop an in-situ bioremediation technology from the engineering aspect to remedy soil contaminated with petroleum hydrocarbons applicable in Taiwan. Microorganisms were used to degrade the organic contaminants both dissolved in the ground water and absorbed on the soil in order to remedy the contaminated soil as well as to restore the ground water quality.
In the experiments using bubble respirometer, results showed that BTEX would begin to inhibit aerobic microorganisms when the concentration was over 416mg/L at 20℃. In the abiotic experiments by adding H2O2 to oxidize BETX, addition of 640mg/L H2O2 under 20℃ and 100 rpm shaking for 48 hours was found to have no impact on the transformation of either 10.4 or 104 mg/L BTEX solutions. Besides, in the evaluation of microorganisms decomposing BETX experiments using H2O2, it wsa found that the aerobic microorganisms could remove 10.4 mg/L BETX at 20℃ in 7days. When chemostats were used to study the kinetic coefficients of BTEX decomposition, it was found that the maximum yield coefficient (Y), the decay coefficient (kd), the maximum specific substrate utilization rate (k), and the half-velocity coefficient (Ks) were 1.12 mg-VSS/mg-BTEX, 0.1/day, 2.81 mg-BTEX/mg-VSS-day, and 27.09 mg-BTEX/L, respectively.
Results of laboratory-scaled upflow biofilter experiments indicated that over 99.56% of a solution containing 10.4mg/L BETX was biodegraded under HRT (Hydraulic Retention Time ) of 2 hours. Under the same HRT, removal rate of a solution containing 104.4 mg/L BETX was 88.67%. In the laboratory-scaled upflow biofilter system, based on the Deep-Biofilm Model, it was predicted that the concentration of benzene could be reduced from 1.73 mg/L to 0.005 mg/L under the retention time of 1.2 hours.
Furthermore, the soil leaching experiments were tested with different leachates. Mass balance calculation indicated that it would take 3212 days to remedy a soil site contaminated with 4000 mg/Kg dry soil BTEX by using a traditional soil leaching system. In this study of leaching with effluent from the aerobic upflow biofilter in combination with the bioremediation technology to remedy the same site, it would take only about 67 days to remove the contaminants in the soil. Besides, addition of nutrients and H2O2 to the effluent from the aerobic upflow biofilter will reduced the bioremediation time to 37days in the same site.
| Identifer | oai:union.ndltd.org:TW/087NPUST515010 |
| Date | January 1999 |
| Creators | Tsang-Shin Chen, 陳滄欣 |
| Contributors | Wen-Chien Kuo, 郭文健 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 130 |
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