Heavy Metals from Tannery Waste: Focus on Chromium Pollution and Bioremediation Technologies

Abstract

Human health has been known to be adversely affected by heavy metals (including chromium), while anthropogenic and industrial activities had increased exposure to these metals. This study was aimed to explore the toxicological effects of chromium and other heavy metals from tannery discharge and highlight the role of microorganisms in mitigating these pollutants. Tannery industries has been known to be one of the world's oldest industry in human civilization. In the past, these industries were majorly set up to satisfy the need for leather and musical instruments. Tanneries are essential part of the leather production chain because they use variety of chemical and mechanical processes to turn raw hides and skins into finished leather goods. Chromium derivatives are among the most important chemicals employed by these industries, thereby causing release of heavy metals into the environment through waste discharge. Due to the hazardous, non-biodegradable and poisonous properties of these metals, they usually pose risk to both the environment and living species. In order to remediate these toxic effluents, indigenous (autochthonous) organisms are thus widely employed. Microorganisms including Aspergillus, Bacillus, Brevibacillus, Burkholderia and Pseudomonas species have been found to possess the potential of removing, detoxifying and remediating some of these waste constituents. Bio-augmentation, biostimulation, bioreduction and biosorption are among the routine approaches employed by these organisms in order to create a safe, less toxic and eco-friendly environments. Further explorations by researchers are therefore needed to fully harness the mechanisms employed by microorganisms in the bioremediation of chromium contaminants from tannery discharge.

Keywords: Tannery, Heavy Metals, Microorganisms, Chromium, Bioremediation