Design of Experiments for the Optimization of Biochemical Treatment of Tannery Wastewater

Almost all tanneries are located on rivers to provide them with process water (30 to 80 m3 for 1 ton of processed raw skins) [1] and for the disposal of their effluents. The effluent from this industry is mainly waterborne [2]. The components of the effluent arise from purification of raw hides and skins before processing as well as from residual chemicals from the production processes. Hence, the tanning industry had been recognized as a major contributor to water pollution problems. Biodegradable organic matter consumes oxygen and nutrients in complex biochemical reactions until rendered inert [3]. This exerts a biochemical oxygen demand as one of the fundamental parameters used to regulate the quality of the effluent [4].