WASTE REMEDIATION

Electrochemical technology can be used in treating wastes whose toxicity or low chemical and biochemical reactivity enable them to resist biological remediation. Applying electricity induces chemical domposition of the contaminants, making the electrolysis products more amenable to conventional treatment.
Advantages include:
• simple equipment that can treat small-volume wastes if necessary
• possibility of either oxidative or reductive treatment
• cost effective, provided that high "current efficiency"
can be achieved. Current efficiency represents the proportion of the
charge passed through the solution that causes contaminant destruction,
rather than parasitic electrochemical reactions or heat production.

Researchers have focused on chlorinated aromatic compounds, such a chlorinated benzenes, chlorinated phenols, and DDT. They plan to study the following areas:
• explosive leachates and wastes that contain reducible nitro compounds
• liquid hog manure, whose odorous components are oxidizable indole
derivatives

Mining Industry Wastes

Acidification of the runoff from coal mines and base metal mines consititutes a major environmental problem. Research is under way or planned for both treating acidified mine waters and preventing their development.

Treatment Technologies

A U.S. government report explored the possibiity of using electrolysis
to eliminate acidity in mine waters, with hydrogen gas as a byproduct.
Guelph researchers will evaluate this technology for:
• recovery of toxic metals
• choice of complementary anode reaction
• choice of electrode material
• current efficiency

Prevention Technologies

Guelph researchers are investigating an innovative technology to prevent
the oxidation of sulfide ores - in mine tailings, for example - by using
scrap iron to maintain a reductive environment. Sulfide oxidation is a
biological process that causes "acid mine drainage", which increases
acidity and toxic metal loading downstream from the mine site.