Heavy metals and organic chemicals that stick to particles of soil could get released into the groundwater. A new procedure developed by Paul Bertsch of the University of Georgia, US, aims at removing these contaminants from the soil. His technique is based on the conventional method of 'pump and treat'.
Polluted water is pumped up, cleaned and then re-injected into the soil. Based on the fact that the contaminants bind with the iron oxide molecules present on the surface of soil particles, large positive ions are injected into the soil to induce the dissociation of oxide molecules from the soil particles.