Combination of Surfactant Solubilization with Permanganate Oxidation for Groundwater Remediation

Remediation of dense non-aqueous phase liquids (DNAPLs) presents a great challenge to modern remediation science and technology. “Pump-and-treat”, a common practice for removal of DNAPL contamination, is proven ineffective, due to low aqueous solubility of the contaminants. Addition of surfactant to “pump-and-treat” operation increased the solubility of the contaminants and decreased the interfacial tension between water and DNAPL, resulting in an enhanced performance and shortened operation time. However, the water withdrawn from of the “pump-and-treat” operation contains high concentrations of contaminants. Onsite treatment of the contaminated water becomes inevitable. Oxidation of DNAPLs by permanganate is another emerging technology. It has been shown that contaminant degradation rate was extremely fast with a half-life in minutes. In addition, the degradation products and intermediates are environmental innocuous. The proposed research is to combine the superior solubilization and mobilization power of surfactants with the fast contaminant degradation rate of permanganate during “pump-and-treat” operation in order to synchronize contaminant solubilization and degradation in a single step; i.e., to achieve simultaneous “pump-while-treat” for DNAPL remediation, instead of the common “pump-then-treat”. This research will focus on reactivity of permanganate with DNAPLs in the presence of surfactant and the effects of concentrations of surfactants, contaminants, and permanganate on contaminant degradation rate via batch tests. Then a series of column and 2-d tank tests will be deployed to verify the batch test results and to determine parameters for future pilot scale field tests. It is expected that the simultaneous DNAPL solubilization/degradation by the proposed “pump-while-treat” system will greatly shorten the treatment time, reduce the operation cost, and speed up the cleanup of DNAPLs. It is hoped that by optimizing pumping rate with the degradation rate, the onsite treatment of contaminated water can be completely eliminated.