| Summary: | 博士 === 國立成功大學 === 資源工程學系碩博士班 === 96 === Trichloroethylene (TCE) was widely used as a solvent in the second 50 years of the 20th century. Because of uniform disposal practices for spent solvents in the past, it has become a major groundwater contaminant in Taiwan. In-situ biological methods offer promise for restoring aquifer contaminated organics, including TCE. Aerobic cometabolism is a powerful biological process that microorganisms growing on primary substrate produce enzyme and fortuitously transform secondary substrate.
The efficiency of in-situ bioremediation is commonly lower than that observed in the laboratory. It is mainly due to the following limitations encountered in the field applications, i.e., (1) the radius of influence of vertical wells is small, (2) the contact of electron acceptors and electron donors with the contaminants is not effective, and (3) clogging of well screens requires huge work-over and remediation costs. Through the pilot test, it was demonstrated that using horizontal porous tubes injection system to inject toluene-vapor could improve above engineering limitations.
Furthermore, this research constructs a system of partial differential equations describes basic processes of microbial growth, utilization of electron donor and acceptor, degradation of contaminant, advective transport, dispersion, and sorption in porous media. Simulations provide good matches to the observed TCE. It was demonstrated that the efficiency of TCE degradation of 0.43 mg/L of influence TCE could reach 90% in 6 meters.
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