Innovation: Can't burn or bury it? Zap it]: Transportable linear accelerator is designed to break down toxic waste

NO-ONE wants toxic waste stored in the neighbourhood, or even burned in an incinerator if it is nearby. If such a facility can find a home, no-one wants the waste brought in past homes, schools or hospitals. But the problem of toxic waste is too big to be washed away, so its disposal remains big business.

It has been estimated that it will cost about dollars 750bn ( pounds 490bn) at today's prices just to clean up the hazardous waste that already exists in the US, using today's technology. But scientists at Lawrence Livermore National Laboratory in California are claiming to have discovered a breakthrough technology that converts certain types of extracted toxic waste into harmless water, carbon dioxide and salt - and does it on the spot without the cost and complications of transport.

The process was developed at the laboratory in collaboration with Schonberg Radiation Corporation, which produces small linear accelerators. A Schonberg subsidiary, Zapit Technology, was recently set up with a worldwide exclusive licence to manufacture and market the technology. The principle is comparatively simple, requiring only a transportable electron beam source and a transformation chamber. The source generates high-energy beams of electrons that travel at nearly the speed of light. Organic toxic waste from contaminated soil, air or water is put into the transformation chamber and bombarded with electrons, which break down chemical bonds in the waste material.

The process works for all volatile organic compounds, including such toxins as trichloroethylene (TCE), carbon tetrachloride and vinyl chloride. For example, bombarding TCE (common in the manufacture of computer chips) turns it into water, carbon dioxide and salt. These residues can be pumped into the atmosphere, and the waste is gone forever.

The commercial aim of Zapit technology is to build transportable zappers that can be taken to the site of a spill or a dump of many kinds of organic pollutants. 'The main advantages of Zapit over current technologies are that it will allow toxic waste to be disposed of on site, without high energy. It can be used across a broad range of compounds and involves no road transport, no air pollution, no hazards to the public,' said Rich Chais of Zapit.

Independent consultants are equally enthusiastic. 'I see a definite role for electron beam technology in toxic waste destruction, and Zapit is an exciting development. One of its beauties is that it can destroy mixed waste, whereas a lot of other technologies are directed at one particular toxic substance,' said Dr Steven Gorelick, a professor of earth sciences at Stanford University with 15 years of experience in dealing with hazardous waste.

So far, the technology has been fully designed, and the transportable zappers, each about 4 by 6 by 8 feet, are in the process of being manufactured. Zapit has contracts in place for 'treatabilily studies' at two US Air Force bases in California. It has collected samples from the bases and successfully 'zapped' them in the laboratory. It is expected the zappers will be installed for on-site trials at one base in July and the other later this year. The company is also in discussion with the Environmental Protection Agency and anticipates that the agency will monitor the on-site tests.

Zapit will not disclose the exact cost of building its system, but it expects to rent the transportable zappers for about dollars 250 per day, including fuel and maintenance costs. At that rate, the system would compare favourably with other methods of waste disposal.

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