The combined electrokinetic and ultrasonic remediation of sand contaminated with heavy metal and organic substance

Abstract

In this study, laboratory experiments involving the simple soil flushing, electrokinetic remediation, ultrasonic remediation, and combined electrokinetic and ultrasonic remediation tests were carried out for analysis of transportation and removal mechanism of heavy metal and organic substance in sand soil. The test setup used in this study was made to combine the electrokinetic remediation processor and the ultrasonic remediation processor. The soil specimens were thoroughly mixed with lead of 500 ppm and ethylene glycol of 500 ppm. The test specimen was then subjected to ultrasonic waves at 30kHz frequency from ultrasonic test setup and to electric power at 1.0V/cm from electrokinetic test setup. It is shown that the electrokinetic technique was the most effective to enhance the removal efficiency of heavy metal such as lead and not effective to enhance the removal efficiency of organic substance such as ethylene glycol from contaminated soil; on the other hand the ultrasonic technique was the most effective to enhance the removal efficiency of organic substance such as ethylene glycol and not effective to enhance the removal efficiency of heavy metal such as lead from contaminated soil. This reinforces the view that the combined new technique of these two techniques can be effectively used in removal of organic substance and heavy metal from contaminated ground at the same time.