electroremediation

Electroremediation is a set of remediation technologies that use an externally applied electric field to mobilize, immobilize, or extract contaminants from soil, sediment, or groundwater. It can be implemented in place (in situ) or by removing material for treatment (ex situ), and is often used in challenging, low-permeability media.

The approach combines electrokinetic and electrochemical processes. Electrokinetic remediation uses electroosmosis, electrophoresis, and electromigration to move charged species, while electrodes induce redox reactions that transform or immobilize contaminants. Local pH changes near the electrodes can enhance dissolution or precipitation and influence contaminant mobility.

Configurations include electrokinetic remediation (EKR) for metals and some organics, and electrochemical remediation (ECR) that relies on oxidation or reduction at electrodes. Hybrid approaches with soil washing or permeable reactive barriers are used in some projects. Electrode materials include graphite, carbon-based materials, and iron or other metal alloys.

Typical targets are heavy metals (arsenic, lead, cadmium, chromium), radionuclides (uranium, cesium), and certain organics responsive to oxidation or reduction. Effectiveness depends on soil conductivity, moisture, and heterogeneity. Energy consumption, treatment duration, and pH control are important design considerations.

Since the 1990s, electroremediation has progressed from laboratory studies to field pilots. It offers in situ treatment with limited soil disruption and multi-contaminant capability, but remains limited by cost, site conditions, and longer remediation times. Ongoing research seeks to improve efficiency, materials, and integration with other methods.