Abstract
In this study the full-scale operation of soil flushing with air sparging to improve the removal efficiency of petroleum at depths of less than 7 m at a military site in Korea was evaluated. The target area was polluted by multiple gasoline and diesel fuel sources. The soil was composed of heterogeneous layers of granules, sand, silt and clay. The operation factors were systemically assessed using a column test and a pilot study before running the full-scale process at the site. The discharged TPH and BTEX (benzene, toluene, ethylbenzene, and xylenes) concentrations in the water were highest at 20 min and at a rate of 350 L/min, which was selected as the volume of air for the full-scale operation in the pilot air sparging test. The surfactant-aid condition was 1.4 times more efficient than the non-surfactant condition in the serial operations of modified soil flushing followed by air sparging. The hydraulic conductivity (3.13 × 10−3 cm/s) increased 4.7 times after the serial operation of both processes relative to the existing condition (6.61 × 10−4 cm/s). The removal efficiencies of TPH were 52.8%, 57.4%, and 61.8% for the soil layers at 6 to 7, 7 to 8 and 8 to 9 m, respectively. Therefore, the TPH removal was improved at depth of less than 7 m by using this modified remediation system. The removal efficiencies for the areas with TPH and BTEX concentrations of more than 500 and 80 mg/kg, were 55.5% and 92.9%, respectively, at a pore volume of 2.9. The total TPH and BTEX mass removed during the full-scale operation was 5109 and 752 kg, respectively.
Highlights
The potential consequences of petroleum and chemical leaks from army bases, gas stations, and industrial complexes have been investigated
Significant total petroleum hydrocarbon (TPH) and BTEX concentrations were reduced by soil flushing at 0.16 L/(min∙m2) for 10 pore volumes at this site [14]
After soil flushing, the residue was still detected at concentrations that were greater than the legal limit
Summary
The potential consequences of petroleum and chemical leaks from army bases, gas stations, and industrial complexes have been investigated. Petroleum-based contaminants are absorbed by the soil or remain as non-aqueous phase liquids (NAPL), which are mostly hydrophobic. Petroleum-based contaminants could be transferred through the ground water and pollute neighboring soils. These pollutants can cause serious environmental problems for neighboring sites [1]. Because soils are usually heterogeneous, it is difficult to predict the behaviors and distributions of soil contaminants and select suitable operations for remediation in the field. A suitable remediation process must be selected in the field based on the hydrogeological character of the site and the type of pollutant
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
