The addition of a new plating line posedeconomical and environmental Opportunities for a hard chromeplating facility. A new wastewater treatment system designeliminates discharge to the sewer via rinse water recycling andchromium recovery and purification. Objectives includedexceeding environmental regulations and reducing costsassociated with plating bath disposal and replacement. Technicalissues to be overcome includes: Balancing the volume of wateradded to the system for rinsing with evaporation water loss;determining the contaminant build rate to establish the chromepurification process rate; and establishing a cleaner replacementrate to provide clean parts without excessive disposal costs. Thefinal design provides multiple operational benefits: Recoveredchromium from rinses is returned to plating tanks for reuse;chromium plating baths are purified, eliminating bath disposal;ion exchange recycles rinse water and provides DI water forrinses; and evaporation further concentrates liquid wastes fordisposal. The only discharge to the city sewer are the dissolvedsolids that enter the plant with the city water. Nearly all thechromium in the rinse water is recovered and returned to the plating bath.
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