In-situ remediation technologies on polluted groundwater

In the east part, around 20 km(2), of the Dawu catchment, including the Xixia and Dongfeng abstraction areas, the groundwater has been polluted by discharge of petrochemical contaminants from an ethylene plant. Petrochemicals have spread over a significant area, up to 10 km(2), at concentrations of 20-48 mg/l. More than 60 organic species were detected in the groundwater. It is very important to control the spread of the polluted groundwater plumes and remove the contaminants remaining in the aquifers. In-situ integrated remediation technologies for groundwater polluted with petrochemicals have been researched in both laboratory and field. The results showed that a hydrodynamic capture technique can remove 80% of the petrochemicals and effectively control the spread of the pollution plume. Air sparging was used mainly-to clean up the volatilizable contaminants and increase the dissolved oxygen in groundwater. Biodegradation and oxidation technologies can remove more than 50% of contaminants in groundwater. Through the operation of the integrated remediation zone, the concentration of the dissolved oxygen content increased from 2 mgL(-1) to 5 mgL(-1) and the petrochemical concentration was reduced from 2.1 mgL(-1) to 0.7 mgL(-1), the removal rate reached 67%.