Chromium-containing wastewater treatment by means of using galvanocoagulators

Abstract

In this study, a galvanocoagulator was used for the treatment of chromium-containing wastewater. Its principle of operation is based on the use of processes for reducing Cr(VI) ions to the Cr(III) state using a galvanic pair “copper-iron” without applying an external electric field. In this case, the reduction of hexavalent chromium ions to trivalent occurs due to the oxidation of iron ions, which, when dissolved, pass into the solution. To speed up the process of iron dissolution, compressed air is supplied to the galvanocoagulator. The conversion of Cr(VI) and Cr(III) into insoluble compounds is performed by adding alkali solutions. The resulting suspension is removed from the water by settling and filtering methods. As a result of research, the possibility of effective treatment of chromium-containing wastewater using the method of galvanocoagulation was established; the technological parameters of the galvanocoagulator were determined. The hydraulic size of the suspension formed after processing of chromium-containing effluents in a galvanocoagulator is determined, which allows designing treatment facilities for the removal of heavy metal hydroxides by settling.