Management of chromium plating rinsewater using electrochemical ion exchange

The chrome plating industry effluent mainly contains chromium(VI) in dragout and rinsewater whose constituents reflect the plating bath characteristics. Normally dragout/dead tank wash water contains about 1% of the plating bath concentration. As chromium(VI) is soluble in all pH ranges, an efficient treatment is required for recovery of chromium for the reuse of treated water. The present study endeavors to recover the chromium by an electrochemical ion exchange (EIX) method. This combines ion exchange (IX) and electrodialysis (ED) for the removal and concentration of chromate ions from the effluent and recycles the treated water for conservation of water. The maximum chromium removal achieved is 98.82% in the batch recirculation mode of operation of EIX at voltage 12.5 V.