Evaluation of surfactant flushing for remediating EDC-tar contamination.
Ethylene dichloride tar (EDC-tar) is a dense non-aqueous phase liquid (DNAPL) waste originated from the process of vinyl chloride production, with major constituents including chlorinated aliphatic and aromatic hydrocarbons. This study investigated the feasibility of Surfactant Enhanced Aquifer Remediation (SEAR) for treating EDC-tar contaminated aquifers. Initial experiments explored the potential to enhance the apparent solubility of EDC-tar using single or mixed surfactants. The results showed that an aqueous solution mixed anionic and non-ionic surfactants (i.e., SDS/Tween 80) exhibited higher EDC-tar apparent solubility and lower surface tension than other surfactant systems tested. Additionally, alkaline pH aids in increasing the EDC-tar apparent solubility. In column flushing experiments, it was seen that the alkaline mixed SDS/Tween 80 solution showed better removal of pure EDC-tar from silica sand porous media. Furthermore, separation of EDC-tar in the surfactant solution was conducted employing a salting-out effect. Significant separation of DNAPL was observed when 13 wt.% or more NaCl was added to the solution. Overall, this study evaluates the feasibility of using SEAR for remediating EDC-tar contaminated subsurface soil and groundwater.
Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan. Electronic address: cliang@nchu.edu.tw.
Chenju
C
Liang
Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan.
Cheng-Lin
CL
Hsieh
D052918:Environmental Restoration and Remediation / Q000379:methods*; D005025:Ethylene Dichlorides / Q000737:chemistry; D060587:Groundwater; D011136:Polysorbates; D012989:Soil Pollutants / Q000737:chemistry; D012995:Solubility; D013501:Surface-Active Agents; D014752:Vinyl Chloride; D014874:Water Pollutants, Chemical / Q000737:chemistry
D005025:Ethylene Dichlorides; D011136:Polysorbates; D012989:Soil Pollutants; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C024565:ethylene dichloride; D014752:Vinyl Chloride
1,2-Dichloroethane; Chlorinated solvents; Ethylene dichloride (EDC); SEAR; Salting out; Soil and groundwater remediation