Electrokinetic Removal of PAHs Using Facilitating Agents

93 ELECTROKINETIC REMOVAL OF PAHs USING FACILITATING AGENTS 

laboratory studies on the electrokinetic removal of PAHs are discussed according to the types of solubility-enhancing agents used and the effects of electrokinetic variables on contaminant removal efficiency. 

According to the Helmholtz-Smoluchowski (H-S) theory, electroosmotic flow is directly proportional to the dielectric constant of the fluid, the zeta potential, and the voltage gradient, and inversely proportional to fluid viscosity. In general, the surfactant solution and the cosolvent have lower dielectric constants than water, and the surfactant solution may even have a much higher viscosity than that of water. Therefore, the addition of facilitating agents results in a reduction of electroosmotic flow as well as an increase in PAH solubility. 

When 3% of Tween 80, a nonionic surfactant commonly used in soil-flushing processes, was applied to an electrokinetic system used to remove phenanthrene from kaolin and glacial tiU, significant desorption, solubilization, and migration of the pollutant occurred near the anode. The phenanthrene concentrations in the 

Brij 30, SDS Kaolin Phenanthrene APG 5g/l— the highest removal ( 75%) Brij30 5g/l—removal was enhanced by acetate buffer ( 71%) SDS 5g/l—44-57% removal (Park et al, 2007) 

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