Novel approaches to the recovery of chromium from the chrome-containing wastewaters of the leather industry

A leather tanning system combining both vegetable tannins and chromium (semi-chrome process) is indispensable for certain types of leathers. However, the effluent generated from such a process presents a problem of separating chromium from vegetable tannins, as the latter tend to precipitate along with chromium. Environmental legislations on the release of chromium into various water bodies demands its recovery and reuse at every possible stage. This investigation describes the development of suitable methods for separation of vegetable tannins followed by recovery of chromium.