Quick Dips

Zapping Toxic Waste

The same electron beam technology used to bombard cancer cells can be harnessed to treat toxic waste, such as the PCB compounds planned for shipment to France, according to a company planning to use the technology in New Zealand.

Commercial Technology Consultancy Associates (Comtech) is investigating the use of a prototype electron beam device to decontaminate pesticides, oil spills and PCBs and PCPs.

Technology expert Dr Steve Matthews, of the Lawrence Livermore National Laboratory, has been using the technology to reduce contaminated water sources from concentrations of thousands of parts per billion to below one ppb. The tests have involved contamination from leaking gasoline storage tanks, explosives, PCBs and other chemicals.

The process starts with drilling holes at a waste site. Steam is then used to flush the contaminants into a storage well, where vacuum pumps suck up the contaminated ground water in vapour form. The vapour is then piped to a mobile unit where the electron beam breaks apart the heavy molecules of the toxic waste into water, carbon dioxide and salts. The equipment used is portable enough to fit on a tractor-trailer rig, and is relatively simple to set up.

Matthews says he has never directly treated contaminated soil in this way, but he believes that such a treatment is feasible. If this is so, the process could also be applied to old timber treatment sites where soil contamination has become a serious hazard.