NSF Award
9561754
95-61754 Rose This Small Business Innovation Research Phase I project will evaluate a multicompartment electrodialysis cell using a new anion-exchange membrane for the separation and recovery of metals in contaminated wastewater. The initial application will be for chromium recovery from plating and metal finishing baths which is of both environmental and economic concern. Regulatory standards are increasingly stringent and significant savings would result from recovery and recycling of the metal. Use of membranes for filtration and concentration is a promising method to address the problem because they operate at low temperatures, do not generate new waste, and are able to handle large volumes. The proposed cell will permit simultaneous removal of both hexavalent and trivalent chromium from the waste stream. In the Phase I program a new membrane with high chemical resistance will be synthesized that is less expensive than perfluorinated membranes. Its chemical stability and electrical properties will be measured and compared to currently available membranes. The membrane will be incorporated into a three-compartment, laboratory-scale electrodialysis cell to demonstrate effective removal of toxic metal cations and hexavalent chromium. The Phase II program will incorporate the membrane into a multicell electrodialysis system to test with industrial effluents. The electrodialysis cell with the new membrane will permit efficient and complete removal of toxic metals from industrial wastewater and concentrate them for reuse or disposal. Commercial applications include treatment of wastewater rinses from electroplating baths, tanning effluents, and metal finishing processes and recovery of strategic metals.
