Studies on recovery of heavy metals from tannery wastewater

Abstract

Heavy metal salts are widely used in the tanning process in the form of Chrome alum and Chromium[III] sulfate. It is a highly toxic metal and cannot be degraded thus deposited and incorporated in water, sediment and aquatic ecosystems which poses various respiratory, skin and other health issues to humans and also cause serious issues to microbial, plant and aquatic life. The cost of these heavy metal salts is high due to which the tanners need a lot of investment for the tanning process because of its abundant use. So, to overcome such issues numerous techniques have been developed for the recovery and reuse of these heavy metal salts from the wastewater of the tanneries to reduce the pollution in the wastewater streams and exempt the tanners from the high cost of these salts.

Exploring Tannery Solid Wastes as a Source of Animal Feed

“…Liquid wastes pose significant challenges, both in terms of volume-with 50,000 L required to produce just 1 kg of leather [37], and composition, laden with heavy metals [38], sulfides [39] and organic matter. The tanning stage introduces tanning liquors, the composition of which varies with the tanning technique and includes substances such as tannins and chromium salts [40].…”