Decolorization Of Azo Dye By Salt Tolerant Bacteria-Suaede Salsa Symbiotic System

The purpose of this dissertation was to investigate the decolorization of azo dye AcidRed B by inoculating salt-tolerant bacteria TAS to the rhizosphere of halophyte Suaede salsa.This dissertation mainly deales with wastewater bio-remediation, which was based on therelevant theories of the organic degradation capabilities of microorganism and the charactersof rhizosphere. The interactions between microorganisms and rhizosphere were studies.Especially the decolorization of zao dye by salt tolerant bacteria TAS and the contribution ofSuaeda Salsa were investigated.Firstly, the capability of salt-tolerant TAS to decolorize azo dyes was investigated, andthe factors effect on acid red B degradation, such as pH, temperature, inocula concentrationand medium volume were discussed. Based on the orthogonal design test. the optimizedcondition was 35℃, pH 8, inocula concentration 8%(V/V) and medium volume 50 ml in 150ml flaks. The performance of acid red B decolorization in 50 mg·L^-1 reached 91% in 10 hourstreatment. The infience of different factors was in the following order: inocula concentration＞temperature＞pH＞medium volume.Secondly, halophyte Suaede salsa was introduced to azo dye wastewater treatment, theeffects of salt and dye concentration on germination as well as root's length of Suaede salsawere investigated, results showed that the biggest germination rate for Suaede salsa was75.6% in distilled water, while with the increasing of NaCl concentration, the germinationrate decreased. When the NaCl concentration reached 2.93%, Suaede Salsa seeds got intodormancy state waiting for the optimized condition of regermination. No obvious influence ofof dye concentration on Suaede salsa germination of was obversed. The germination rate was57.8% even when the dye concentration reached 4500 mg·L^-1, but the effect on the root'slength of Suaede salsa was evident, the restraining rate of the root's length was as high as68% in 5000 mg·L^-1 dye concentration.At last, the exudates of Suaede salsa were added to enhance the decolorization effect ofazo dye. Basing on pilot study of the effect of salt-tolerant bacteria and Suaede salsa on azodye decolorization, the salt tolerant bacteria-Suaede salsa symbiotic system was constructed,which showed better performance of Acid red B decoloration. With the influent concentrationof Acid red B 800 mg.L^-1, the optimized decolorization condition of the system was 35℃, pH8, inocula concentration 16% (V/V) and medium volume 75ml in 150ml flasks.