Remediation of BTEX Contaminated Site by Air Sparging
In this field-scale study, air sparging (AS) system was applied at a petroleum-hydrocarbon spill site to remediate contaminated soil and groundwater in situ. The objective of this study was to evaluate the effectiveness of the AS system on volatile organic compounds (VOC) removal via the volatilization mechanism. Moreover, the AS system would also enhance the in situ bioremediation process due to the increased oxygen concentration in the subsurface.
Results from the preliminary site characterization show that high concentrations of benzene and toluene were present in the subsurface in the western part of the site. Up to 15.62 and 30,957 mg/Kg of benzene and toluene were detected in soil samples, respectively. Moreover, up to 0.068 and 4.8 mg/L of benzene and toluene were observed in groundwater samples, respectively. The following remediation activities were conducted during the one-year investigation and remediation period:
1. Construction of four recovery wells were for light non-aqueous phase liquid (LNAPL) and contaminated groundwater extraction to prevent the expansion of VOC plume. The extracted groundwater was delivered to the wastewater treatment plant for treatment before discharge.
2. Installation of ten air sparging wells to enhance the removal of VOC through volatilization and biodegradation processes.
3. Conduction of (1) soil gas survey, (2) soil and groundwater sampling and analyses, and microbial enumeration periodically to evaluate the effectiveness of AS on VOC removal.
Results from the field-scale study indicate that the AS system is able to effectively contain the plume. This can be confirmed by the following findings: (1) decrease in VOC concentrations in both soil and groundwater, (2) increase in carbon dioxide and increase in oxygen concentrations in the soil gas samples, and (3) increase in bacterial population in soil samples. Results from this study indicate that AS system can effectively contain the plume and manage this petroleum hydrocarbon spill site.
Advisor:none; none; none; none
School:National Sun Yat-Sen University
School Location:China - Taiwan
Source Type:Master's Thesis
Keywords:lnapl petroleum hydrocarbon biodegradation voc in situ air sparging bioremediation
Date of Publication:08/19/2004