Abstract |
The technical feasibility of electro-acoustic soil decontamination process through lab experiments demonstrated the removal/concentration of heavy metals such as cadmium and zinc. Results of the decane contaminated soils were, however, inconclusive. The ESD process is based on the application of a d.c. electric field and acoustic field in the presence of a conventional hydraulic gradient to contaminated soils to enhance the transport of liquid and metal ions through the soils. Electrodes (one or more anodes and a cathode) and an acoustic source were placed in contaminated soils to apply an electric field and an acoustic field to the soil. This process works especially well with clay-type soils having small pores or capillaries, where hydraulic permeability is very low. The development program included a literature review, soil characterization, design and construction of the laboratory ESD unit, and lab scale experiments with soils contaminated with decane, zinc and cadmium. Evaluation of the experimental results indicated that application of the field sources reduced the heavy metals zinc and cadmium more than 90% in the treated cake. Tests yielded 10-20% decane removal. |