Bioremediation of Tannery Wastewater

Abstract

Tannery effluent is a serious environmental threat due to its high chemical levels which include salinity, organic load (chemical oxygen load or demand, biological oxygen demand), inorganic matter, dissolved and suspended solids, ammonia, total Kjeldahl nitrogen, sulfide, chromium, chloride, sodium and other salt residues, heavy metals, etc. These components present in the effluent affect agriculture, human beings and livestock. Exposure to chromium and other pollutants in tannery effluent increases the risk of dermatitis, ulcer, nasal septum perforation and lung cancer. The environmental protection regulations stipulate that industries are not allowed to emit sulfide and chromium in the wastewater. Thus, removal of these high-strength toxic chemicals from the wastewater is very important. Treatment of tannery wastewater is carried out by physical, chemical, biological, or combination of these methods. Biological treatment of wastewater is more favorable and cost effective as compared to other physiochemical methods. A number of bioremediation strategies have been reported in the recent past showing their potential in the treatment of tannery effluent. The present review summarizes the recent advances in bioremediation of tannery effluent.