Study On Decolourization Of Dye Wastewater By Photosynthetic Bacteria

Applicaton of photosynthetic bacteria on the treatment of simulated dye wastewater was investigated in this dissertation.Firstly PSB was acclimated from sea mud Under selective culture conditions . pure culture of PSB was isolated by means of agar dilution.Secondly, Effect of temperature,pH and salinity on PSB were investigated on the base of pure culture .Then the effects of ocean photosynthetic bacteria on decolourization of five dyes under different conditions such as the choice of the carban source, pH, temperature, C:N of the culture, dye concentration, the dye structure were studied. Results show that ocean photosynthetic bacteria could tolerate high salinities and five different dyes were decolorized by it. The effect of temperature on the dye with different structure is different. The decolourization rate was optimal at temperature 30-35℃, X-3B was degraded well under the condition of PH ranged from 3 to 10. The activity of tamed bacteria was better. X-3B did not inhibit cell growth when its concentration≤100 mg/L.When the carbon source was glucose and nitrogen source was yeast extract, the decolourization rate reduced with the concentration of glucose increasing ; the concentration of the yeast extract affected the decolourizaion obviously and its major role in the medium is a N-balancing compound ; the decolourization rate is optimal when the concentratin of glucose and yeast extract was 0.125 % and 0.3 % respectively . Under the optimal condtion , X-3B was decolourized well when the dye concentration≤500 mg/L and it did not inhibit cell growth; with 500mg/L