Practices on ecological chromium tanning system

Chromium tanning using less chromium salts at higher initial pH values is one of the approaches offered in recent years in order to overcome environmental problems caused by conventional chromium tanning. However this system couldn't be directly switched to application due to its potential risks. In the present study this ecological approach was investigated at industrial scale. The variables used in the research were: pre-tanning agents, initial pH of tanning and tanning agents. Various wet-end and finishing processes depending on three different types of products were applied according to the company's production line. Chromium contents of the leathers and remaining amounts in effluents were determined for each trial. Also, the physical properties of the leathers were investigated. Along with maintaining similar properties and quality from the produced leathers, chromium remaining in residual baths could be reduced up to 92 and 76% by alternative formulations respectively in 500 kg and 6000 kg batches.