Chromium is a major pollutant in wastewaters from some electroplating operation. It can be effectively removed from rinse waters by adsorption on activated carbon, which must be regenerated when saturated with chromium to its upper limit. This study was concerned with the best means of regenerating the carbon under conditions which would return it as closely as possible to its original adsorptive capacity. The tests were conducted (1) on a laboratory scale to determine the effects of basic and acidic media on regeneration of chromium-loaded activated carbon and (2) in a small pilot plant unit on the basis of the best results of the laboratory-scale work. In the latter case, tests were conducted on the unit operation for eight adsorption-desorption cycles. The overall results of this study suggest that a chromium removal unit could be installed in many of the small plating plants, relieving the burden on municipal sewage systems, and bringing the plating plant into compliance with local and Federal regulations.

EPA grant no. S802113; program element no. 1BB036. Report prepared by Battelle Memorial Institute, Columbus Laboratories, Columbus, Ohio. Includes bibliographical references (page 31).