A GROWING PROBLEM: OXIDIZED CONTAMINANTS
Applied’s HiPOx andPulseOx technologies are based on oxidation chemistry, essentially the breakdown of solvent and petroleum contaminants by adding oxygen molecules. But some contaminants are already in a highly oxidized state, and advanced oxidation technologies will not be effective in treating them.
Reductive chemistry, or breaking down contaminants into benign materials by subtracting or taking away oxygen molecules, is appropriate for contaminants in a highly oxidized state.Two oxidized contaminants ideally suited for treatment by reductive chemistry are perchlorate (ClO4־) and nitrate (NO3־), both of which are major groundwater contaminants.
Nitrate is an even more ubiquitous contaminant in drinking water supplies across the U.S. Agricultural run-off has been a major cause of elevated nitrate levels in groundwater supplies. Both contaminants have caused many water supply wells to be taken off line by public and private water suppliers.
Conventional treatment technologies such as filtration, carbon adsorption and air stripping are ineffective in removing perchlorate and nitrate from water supplies. Advanced technologies for removing these contaminants include ion exchange and reverse osmosis.
In both cases, the technologies work by actually concentrating the contaminants in a water stream that must be further processed or managed at a waste disposal facility. For large applications, these technologies can generate thousands of gallons per day of concentrated waste. Management of these secondary wastes is a major contributor to the total operating costs of these technologies.
MBfR: A LIGHT AT THE END OF THE TUNNEL
A new reductive technology, the hydrogen-based, membrane biofilm reactor (MBfR), has recently been pioneered by leading scientists at Northwestern University. The MBfR technology has successfully destroyed dissolved-phase recalcitrant groundwater contaminants, including perchlorate and nitrate, by converting (reducing) them to benign materials in numerous laboratory and pilot scale tests. The technology shows tremendous promise for large-scale applications.
Like Applied’s flag ship HiPOx technology, the MBfR is a destructive technology. Instead of concentrating the contaminants for further processing, it destroys the contaminants on-site by converting them to benign materials. Large volumes of secondary waste are avoided and in comparison to conventional technologies, it’s a waste free process.
In a hydrogen-based MBfR, hydrogen gas diffuses through the wall of a composite membrane and an autotrophic biofilm naturally develops on the outside of the membrane where the bacteria’s electron acceptor is an oxidized contaminant (e.g. NO3־ or ClO4־), supplied from the water. Nitrates are reduced to harmless nitrogen gas and perchlorates are reduced to harmless chloride ions.
APPLIED TO CHAMPION MBfR COMMERCIALIZATION
Applied has licensed the MBfR from Northwestern University, will further develop, and fully commercialize this innovative technology. We believe there will be many exciting applications. If you would like to explore whether the MBfR technology is right for your needs, please contact us.
For a copy of Applied's brochure on the MBfR technology, in pdf format: please click here.
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