ABSTRACT
Low Cost Electron-beam Remediation of Industrial Water and Wastewater
Electron-beam irradiation has been shown to be effective in remediation of both chemical and biological contamination in ground water and wastewater. For organic contaminants of ground water (MTBE, PCE, PCB, TCE), e-beam treatment produces a sequence of reduction and oxidation reactions that are effective in degrading both the contaminant molecule and any byproducts to yield safe end products. For biological contaminants (E. coli, Salmonella, Cryptosporidium), e-beam kills both pathogenic bacteria and spores. A dose of 4 kGy reduces contaminant populations by a factor of >10,000. Treatment is most effective when given in sequential doses. The main impediment in bringing e-beam treatment into practice has been the cost of conventional e-beam technology. For economic use in treating drinking water, a cost of around $1/1000 gal is a limit. For industrial waste streams, a cost of around $2-5/1000 gal may still be attractive. One investigator has invented a stacked-deck transformer (SDT) accelerator that can deliver multiple electron beams with aggregate beam power of about 200 kW, which is four times that in conventional industrial accelerators. The accelerator technology is much simpler and less expensive than conventional systems, and uniquely supports parallel flows and sequential treatments. Its projected process cost for large-volume applications is less than $1/1000 gal.
An industrial wastewater application for e-beam treatment has been identified that presents a very nice opportunity for first use of e-beam treatment in remediating hazardous chemicals from a waste stream. A major petrochemicals refinery on the Houston Ship Channel has a 15 GPM flow of effluent from a process that manufactures a number of chemicals, notably including MTBE. While the effluent flow is relatively modest in volume, it contains high levels of contaminants and must be remediated to EPA-permitted levels before discharge. Currently the company contracts to have the water treated in an aerobic pond system, but the levels of contaminants periodically kill the flora in the ponds and cause a shutdown of the entire treatment plant. Consequently the petrochemical company is being charged a high cost ($50/1000 gal) to treat the stream.
The primary goal for this group will be to develop an effective multi-disciplinary team that becomes the foundation for a research program in e-beam applications to water and wastewater treatment. This will be accomplished by first having each investigator become versed in the aspects of e-beam technology known to the others. Then, meetings will be held to identify the most promising applications of the technology and the most suitable funding sources. A first priority will be treatment of industrial wastewaters contaminated with MTBE. As the research program evolves, others will be added with more specialized expertise.