Technology to turn toxic waste into energy

Charles Q. Choi

A new technology will remove toxic substances from ore and create electricity at the same time.

Contaminated water from coal and metal mines is a serious source of pollution that threatens clean water and biological health. This water contains toxic metals such as arsenic, lead, copper, iron and cadmium. The purification process of these substances is very difficult and expensive.

Environmental engineers at Pennsylvania State University are developing a new device that addresses the source of pollution and creates a new source of energy. They tested the lab version of the device with the same form of iron-contaminated liquid as the water at the mines. This device attacks dissolved iron and releases electrons from iron. The generated power causes iron to be insoluble and thereby pulls waste out of the water.

The iron chips collected by the device can be used for paints or other products. In principle, this device can handle other metals in wastewater. Researcher Brian Dempsey said: 'We are working on other research projects for arsenic and other contaminants.'

Currently, the device can only produce a modest amount of energy. Researcher Bruce Logan interviewed LiveScience: 'A version the size of a refrigerator will provide enough energy to light a light bulb.' Researchers hope to significantly improve production energy and reduce costs.

The study was published in the December 1 issue of the journal Environmental Science & Technology.