A hybrid treatment process for product recycling from tannery process effluent and soak liquor

The sulfate rich saline tannery effluent (SRSTE) was treated effectively using halophilic bacterial pretreatment followed by electrochemical oxidation (hybrid treatment). Aerobic degradation was done using halophilic bacterial consortia isolated from the tannery soak effluent, resulted in 76 % COD removal after 6 days. The remaining COD was reduced by electrochemical oxidation (EO). In electro oxidation process (without aerobic pretreatment), 24 h of electro-oxidation was needed to complete COD removal. The process efficiency was analysed through Fourier transform infrared spectroscopy (FTIR), high performance liquid chromatography (HPLC), total organic carbon (TOC) and chemical oxygen demand (COD). The reduction of sulfate could not be noticed in presence of halophilic bacteria in aerobic treatment. The energy consumption for COD removal was about 0.343 and 0.020 kW h/g(1) in electrochemical oxidation and hybrid treatment process respectively. Besides, chloride loss was also higher in EO when compared to hybrid approach. Hybrid treatment process was proved to be an effective method for treating SRSTE. The mixed salt was recovered and used for dyeing purpose.