The coupled effect of electrokinetic and ultrasonic remediation for the treatment of contaminated sediments

This paper presents a study on an electrokinetic and ultrasonic remediation for treatment of contaminated sediments. The quantity of contaminated sediments such as river and harbor sediments, mineral wastes, mining wastes, and dredging wastes is increasing significantly. These sediments contain significant colloidal fraction and contaminants. Its potential hazards of these sediments in subsurface environments are existed. In these cases, it is needed to remediate and treat the contaminated sediments for pollutant extraction. A series of laboratory experiments including variable remediation methods such as simple soil flushing, electrokinetic remediation, ultrasonic remediation, and electrokinetic with ultrasonic remediation were performed with the contaminated sediment specimens. The electrokinetic experimental apparatus consisted of electrokinetic remediation and ultrasonic remediation units with direct current power supply and acoustic wave. From the test results, a significant investigation is derived for the mechanisms associated with sediments contaminated with heavy metal and organic substance in which simultaneous remediation processes are involved by electrokinetics and ultrasonics. The coupled effects of electrokinetic and ultrasonic remediation and contaminant transport are analysed.