Fast, low-cost electrochemistry filtration process for remediating heavy-metal contaminated soil

Stanford researchers within the Cui Lab have developed a low-cost, recirculating soil washing and filtration system to selectively remove heavy metals including copper, lead, and cadmium, from contaminated soil in a short time while preserving nutrients for agricultural use.

Soil remediation efforts for heavy metal contamination can be costly, energy and time intensive, and can produce secondary toxic products or pollution. By using alternating current instead of a direct current electric field, energy consumption for this technology is greatly reduced compared to conventional electrochemical remediation. This sustainable method achieves high degrees of contaminant removal for heavy metals at initial concentrations varying from 100 to 10,000 ppm, all reaching corresponding regulation levels for residential scenarios after a treatment time between 30 minutes to 6 hours with no resulting secondary toxic pollution.

Figure:

Figure description:
Schematic of an AACE remediation system. EDTA solution is recirculated to wash the contaminated soil. The AACE filter recovers heavy metal cations from the washing effluent and recycles the EDTA solution for repeated use.

Image credit:https://doi.org/10.1038/s41467-019-10472-x

Stage of Development

Stanford News
Stanford develops an experimental process to rinse heavy metals from toxic soils, 06.04.2019