RECOVERY OF SULFURIC-ACID FROM WASTE ALUMINUM SURFACE PROCESSING SOLUTION BY DIFFUSION DIALYSIS

Diffusion dialysis with anionic ion exchange membranes was employed to recover sulfuric acid from the waste acid solution of aluminum surfac e processing plant. Experiments were conducted to examine the dialyzer performances under various operating conditions, including feed flow rates, sulfuric acid concentration in the feed solution, temperature a nd number of pieces of ion exchange membrane. Diffusion dialysis was f ound very efficient for this purpose. Based on the test results, optim um operating conditions of these variables were identified. Preliminar y economic evaluation of the process indicated that diffusion dialysis is highly viable for sulfuric acid recovery due to its short payback period. (C) 1998 Elsevier Science B.V. All rights reserved.