Leather tanning consumes a huge quantity of water which ultimately goes to the environment as wastewater and degrades the environment. The study deals with the utilization of spent tea leaves as the adsorbent for the reduction of Biochemical Oxygen Demand (BOD) from tannery wastewater. The characteristics of raw effluent like initial COD, BOD, pH, and EC were measured. The experiments were carried out in the batch process for simplicity. The maximum percentage of BOD reduction was found 85.88 at 05 mg/l dose of adsorbent. The results of BOD reduction follow the Langmuir and Freundlich adsorption isotherm.

Treatment of tannery wastewater by electrocoagulation (EC) process was investigated in this study. Treatment of the wastewater was carried out by an electrochemical batch reactor equipped with aluminum electrodes, which were connected parallel to each other. The optimum operating conditions were determined and applied to the process. The maximum obtained values for COD, color and turbidity removal efficiencies were 100%, 84%, and 85%, respectively, for an operating time of 21 minutes.The obtained results indicate that EC reactor is the applicable option to treat tannery industry wastewater in terms of removal efficiency and operating cost.

Leather tanning industry, considered one of the polluting industries, poses various environmental threats to its every sphere. It produces various types of solid wastes as well as liquid wastes. Among the solid wastes, untanned raw trimmings contribute for about 5-7% of the total quantity of raw materials processed. If suitably utilized, these by-products of tanning industry could be a useful resource for various applications. This research work deals with utilization of raw trimmings of tannery solid waste to protein hydrolysate by acetic acid with varying acid concentration, acid solution, temperature and time. The maximum about 76% protein hydrolysate was obtained at 1.5M acid concentration and 80ºC.