Combined ultrasonication and electrokinetic remediation for persistent organic removal from contaminated kaolin

Electrokinetics alone (EK) and ultrasonically enhanced electrokinetics (EK-US) tests were studied to compare and examine the combining effects of these two methods on the removal of the three persistent organic pollutants (POPs): hexachlorobenzene (HCB), phenanthrene (PHE) and fluoranthene (FLU) from kaolin. Two pair tests were conducted into two experiments with different initial low (100 mg/kg) and high (500 mg/kg) contaminant concentrations. Results from the experiments show that, generally, EK-US tests have higher electroosmotic flow, higher current and better performance than EK alone tests. However, ultrasonic enhancement can increase the removal rate only up to about 10% more. Among the three POPs, HCB is the most difficult to treat because of its very stable structure while the other two PAHs are easier to remove.