Description
Tanning is a set of processes that turns animal hides into leather appropriate for making a range of consumer products. Tannery processes treat raw animal hides to remove hair and leftover animal parts, stabilize the hides so they do not decompose and then dye or treat them to create a finished product. Products include belts, shoes, clothing, pocketbooks and additional consumer items. These processes are done in many steps using many different types of chemical and mechanical means.[1] Sulfides are used to break down the hair and chlorides are used in the pickling or preservation process. Of particular concern is the use of chromate salts in the stabilization process, because, unless well-controlled, hazardous chromium wastes and chromium-contaminated wastewater can be released. In addition to these chemicals, massive amounts of water are used in the process.[2] Up to 30 or 40 cubic meters of wastewater is created per ton of raw material processed.[3]....