Abstract

Tannery wastewaters taken at the stage of chromium fixation were studied using a treatment by partial freezing. The ice formed shows chromium levels lower than the initial wastewaters. The process can be used for switching from chromium (III) containing wastewaters to practically total reuse. The water obtained by the melting of ice crystals still contains some chromium traces but can be used for hide soaking and washing, or for the preparation of pickling solutions. After basicity correction and the addition of any supplementary chromium needed, the chromium-enriched solution can be used for tanning.