Sequential oxic-anoxic bio reactor for the treatment of tannery saline wastewater using halophilic and filamentous bacteria

The present investigation was focused on the removal of dissolved organics and suspended solids from tannery saline wastewater [TSWW]Raw, known as soak liquor, by sequential oxic-anoxic bio reactor (SOAR) using halophilic bacteria 3and filamentous bacteria (FB). The high concentration of Sodium Chloride (NaCl) in tannery wastewater retards biodegradation of dissolved organics. The aim of this study was to cultivate halophilic bacteria and facultative bacteria from tannery soil supported sewage culture using soak liquor nutrient, for the degradation of organics in [TSWW]Raw. SOAR was used for the maximum removal of proteins, 47.4%; carbohydrates, 44.8% and lipids, 70.4% from [TSWW]Raw at optimum HRT of 12 h. The Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and suspended solids were removed by 36.8%, 31.2% and 72.6% respectively from [TSWW]Raw containing total dissolved solids (TDS) concentration of 6-7% (w/v) without the addition of any coagulants. The degradation of proteins (albumin and globulin) in [TSWW]Raw was evaluated and confirmed through circular dichroism (CD) studies. Further, the removal of organic compounds was characterized by UV-vis spectroscopy and fluorescence spectroscopy, TGA-DSC and FT-IR studies. The presence of filamentous bacteria was confirmed through SEM analysis.