Dewatering and decontamination of artificially contaminated sediments during electrokinetic sedimentation and remediation processes

Sediments contain significant water, clay, colloidal fraction and contaminants, and can result in soft strata with high initial void. Its potential hazards of the sediments are existed in subsurface environments. Electrokinetic technique has been used in sedimentat ion and remediation for volume reduction of slurry tailing wastes and extraction of contaminants from contaminated soils. In this research, the coupled effects of sedimentation and remediation of contaminated sediments are investigated using electrokinetic sedimentation and remediation techniques from experimental aspects. A series of laboratory experiments including variable conditions such as initial solid content of the specimen, concentration level of the contaminant, and magnitude of applied voltage are performed with the contaminated sediment specimens mixed with ethylene glycol. Commercially available high specification Kaolin was used to simulate sediment. From the test results, the quantity of accumulated outflow is increased with increasing voltage applied, otherwise the quantity of accumulated outflow is decreased with increasing solid content and contamination level. The removal speed and time of contaminant was shortened with increasing voltage applied, and with decreasing solid content and contamination level.