| Summary: | 碩士 === 國立中山大學 === 環境工程研究所 === 102 === In this study, landfarming and pump-and-treat system were combined to remediate diesel-oil contaminated groundwater and soils. Results from the soil analyses show that the total bacterial counts reached 2.09×106 CFU/g. This indicates that the indigenous bacteria were able to biodegrade the petroleum hydrocarbons in the soils. However, the total nitrogen, phosphorus, and water content were too low to meet the allowable levels of bioremediation. Thus, addition of water content and nutrients needs to be performed to improve the efficiency of landfarming. Results from the microbial diversity analyses show that the petroleum-hydrocarbon degrading bacteria existed in the soils. Thus, landfarming would be an optimal remedial option at this site. Approximately 25% loss of the soil petroleum hydrocarbons was due to the vaporization mechanism during the landfarming process. Up to 68% of the total petroleum hydrocarbon (TPH) removal was obtained in the test using compost as the nutrient and bacteria amendments. Results also show that the addition of petroleum-hydrocarbon degrading bacteria, sludge, and compost had significant TPH degrading rates. The soil TPH concentration dropped to below 1,000 mg/kg after 16 days of operation. Up to 91% of TPH removal could be obtained when bulking agent, organic amendments, and bacteria were added in soils during the soil agitation process. For groundwater remediation, the benzene concentrations in two wells reached 0.056 and 0.12 mg/L before the application of the pump-and-treat system. After the operation of the pump-and-treat system, benzene concentrations in the two wells dropped to below 0.0089 and 0.0017 mg/L, which were lower than the groundwater standard for benzene 0.05 mg/L. Results indicate that the application of landfarming and pump-and-treat system could effectively remediate the polluted soils and groundwater at the petroleum-hydrocarbon contaminated site.
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