Remediation of heavy metal contaminated soil by asymmetrical alternating current electrochemistry

摘要

Soil contamination by heavy metals constitutes an important environmental problem, whereas field applicability of existing remediation technologies has encountered numerous obstacles, such as long operation time, high chemical cost, large energy consumption, secondary pollution, and soil degradation. A design and demonstration of a method is provided which is based on asymmetrical alternating current electrochemistry (AACE) that achieves high degrees of contaminant removal for different heavy metals (Cu, Pb, Cd) at different initial concentrations (from 100 to 10,000 ppm), all reaching corresponding regulation levels for residential scenario after rational treatment time (from 30 min to 6 h). No excessive nutrient loss in treated soil was observed and no secondary toxic product was produced. Long-term experiment and plant assay showed the high sustainability of the method and its feasibility for agricultural use.