Advanced Technology Like Reverse Osmosis in Tannery Effluent Treatment to Enhance the Reusing Potential of Treated Effluent at Various Stages of Tanning Process

Reverse Osmosis (RO) treatment has shown to be highly effective in the removal of organic pollutants and salts from tannery effluent providing for high quality water recycling. In the present study, the outlet of Activated carbon filter water contained p^H 6.63, Total Suspended Solids (TSS) 25 mg/L, Total Dissolved Salts(TDS) 2650 mg/L, Chlorides 1490 mg/L, Chemical Oxygen Demand (COD) 110 mg/L, and Biological Oxygen Demand(BOD5) 34 mg/L. This one was reused at Soaking process, Machine cleaning and Place washing. After the Reverse Osmosis process, the treated water collected at RO outlet contained the pH 6.31, TSS Nil mg/L, TDS 560 mg/L, Chlorides 100 mg/L, COD 10 mg/L and BOD₅ 3 mg/L, Due to drastic reduction of Dissolved salt and organic pollutants content, the treated water can be reuse at all stages of semi finished tanning processes and Chrome processes. Recycling gives excellent results without causing any detrimental effects on leather quality. This RO technology shows to be a technical and economical feasible option for effluent treatment and high quality water recycling. An average reduction of 91% COD and 91% BOD5 and a stable membrane performance was achieved. The effluent quality complies with the Tamil Nadu Pollution Control Board discharge consents for tannery effluents.