Electrochemical treatment and associated chemical modifications of clayey soils: a review

Electrochemical treatment of soil, ECT is the technique of deploying an external electric potential for introducing stabilizing chemicals into the intended zone of soil improvement. The current flow modifies the basic soil-electrolyte chemistry, reflected mostly in the form of soil pH. In view of this, the manuscript reviews the alterations in clay fabric and ionic-species interactions instigated with the modifications in surface charge due to soil pH alterations. The derived consequences of system chemistry changes are discussed concerning its impact on the migration mechanisms during ECT viz. electro-osmosis and electro-migration. Though ECT is familiar to the research fraternity for decades, the attempts made hitherto for compiling the available literature on ECT are limited. Given this, by depicting the pioneering developments over time, the present study also provides a concise review of the research carried out in the area of ECT by highlighting the impact of electrochemical modifications upon the treatment efficiency.