Biotreatment of the Wastewater Containing Insoluble Pigment by Halomonas Strain Gb

Industrial dyeing processes produce a large amount of wastewater that contains many organic compounds such as different type of dyes and pigments, dispersing agents, surfactants which are difficult to treat. Considering that little studies have been done on biodegradation of oilsoluble azo dyes, the lake of this issue is completely felt. In this study, biotreatment of Toluidine Red (TR), an oilsoluble azo dye, was optimized under different environmental conditions. Halomonas strain Gb was capable of decolorizing TR at a pH range of 6.59.5 and temperature range of 2540 °C. The optimum condition was 25 mg/L dye, pH=6.5, temperature 35 °C and 5% (w/v) NaCl. UVVis spectrophotometric method, highperformance liquid chromatography (HPLC) and gas chromatographymass spectrometer (GCMS) analyses confirmed that biodegradation of TR was accrued successfully. According to the results, Halomonas strain Gb can be recommended as practical bacteria for the treatment of industrial wastewaters containing azo dyes with different water solubility.