SLUDGE RECLAMATION USING COUPLED-TRANSPORT MEMBRANES

IN 1980 THE METALS AND ELECTRONICS INDUSTRIES GENERATED OVER SEVEN MILLION TONS OF HAZARDOUS WASTE AT A COST OF $100TO $400/TON. THESE SLUDGES, WHICH CONTAIN SUBSTANTIAL AMOUNTS OF MIXED HEAVY METALS, PRESENT A SERIOUS DISPOSAL PROBLEM AND REPRESENT A WASTE OF NATURAL RESOURCES. THE INTRINSIC VALUE OF METAL SUCH AS NICKEL, CHROMIUM, AND TANTALUM CONTAINED IN THESE SLUDGES IS HIGH, PROVIDING A SIGNIFICANT INCENTIVE FOR THEIR RECOVERY. IT IS THE OBJECTIVE OF THE PROPOSED PROJECT TO DEVELOP AN ECONOMICAL, ENERGY-EFFICIENT PROCESS FOR THE RECOVERY OF CERTAIN METAL VALUES IN A USABLE FORM FROM THESE INDUSTRIAL SLUDGES, THEREBY CONSERVING VALUABLE RESOURCES AND CONTROLLING THE AMOUNT OF WASTE ULTIMATELY GENERATED. SINCE A CLEAN SEPARATION OF THE VARIOUS METALS IS THE CRITICAL STEP IN ACHIEVING THIS OBJECTIVE, THE BULK OF PHASE I RESEARCH WILL BE DIRECTED TOWARD EVALUATING A NEW MEMBRANE-SEPARATION PROCESS KNOWN AS "COUPLED TRANSPORT" FOR THE CONTINUOUS SEPARATION OF METALS FROM WASTE SLUDGES. ONCE EFFECTIVE SEPARATION HAS BEEN DEMONSTRATED, THE COUPLED-TRANSPORT PROCESS CAN BE COMBINED WITH EXISTING, WELL-ESTABLISHED RECOVERY TECHNIQUES TO PRODUCE A COST EFFECTIVE SYSTEM CAPABLE OF CONVERTING CERTAIN WASTE SLUDGES INTO USABLE MATERIALS.