【作者】 潘家胜；

【导师】 孙德智；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2007， 硕士

【摘要】 在工业废水当中,来自印染和纺织工业的印染废水是最难处理的废水之一,这是因为染料是一种合成的、含有复杂的芳环类结构的化合物,很难被生物降解。近年来,全世界染料年产量已超过7×10~5吨,品种达千种以上,其中偶氮染料所占比例最大,约占总染料产量的60%以上。本文是以含偶氮染料活性黑5(RB5)的印染废水为研究对象,分离到在好氧条件下和厌氧条件下有较高脱色能力的菌株各10株,其中16号菌株和19号菌株脱色效果最好,经进一步筛选将16号菌株作为最佳脱色菌。采用常规细菌鉴定方法,依据该菌株的形态、生理生化特征,初步鉴定为沼泽红假单胞菌属(Rhodopseudomonas palustris)。又根据16号菌株的16S rRNA基因序列分析,菌株与已知沼泽红假单胞菌的标准菌株相似度为97%,确定本实验室分离所得的16号菌株为沼泽红假单胞菌,将其命名为沼泽红假单胞菌W1。研究表明菌株W1对活性黑5的脱色是通过微生物共代谢机理实现的。乳酸钠是本研究的最佳外加碳源,氯化铵是最佳氮源,最佳浓度分别为2g/L和1g/L。菌株W1对环境中的pH值和盐度有较大的适应和耐受能力,在光照厌氧pH为5~10、黑暗好氧pH为6~11范围内和高盐度环境中都能够保持较高的脱色降解活性,同时该细菌对于大部分种类染料都有良好的降解效果,然而对COD降解效果较差,采用光合细菌-活性污泥法可以提高COD降解效果。通过紫外-可见光谱、液质联用技术分析可知,活性黑5脱色机理主要是偶氮双键在催化作用下进行的还原裂解反应,同时在脱色过程中伴随产生了中间产物芳香胺类化合物。在光照厌氧条件下,染料初始浓度在50~500mg/L之间变化时,菌株W1对染料活性黑5的脱色过程符合一级动力学方程。降解速率与染料初始浓度之间关系符合Michaelis-Menten方程,反应动力学参数Vmax=80mg/(L.h),K_m=348.20mg/L。更多还原

【Abstract】 Among industrial wastewater, dyeing wastewater from printing and textile industries is one of the most unmanageable wastewater. The reason is that dyes usually have a synthetic origin and complex aromatic molecular structures, which are hard to biodegrade. In recent years, it is reported that there are over 1000 kinds of commercially available dyes with a production of over 7×10~5 ton. Among these kinds of dyes, azo dyes are the most widely used, they account for 60% of dyes known to be manufactured.Considering dyeing wastewater containing Reactive Black 5(RB5) as the subject in the study, which is belong to azo dyes, 10 high-efficient decoloring strains are separated under aerobic condition when the other 10 strains under anaerobic condition. Thereamong, No.16 strain and No.19 strain have higher decolorization capacity. No.16 strain is further screened as the optimal decoloring strain. On the basis of the configuration and physiological and biochemical characteristics of the strain, the strain is primarily identified as Rhodopseudomonas palustris by way of introducing conventional bacterium assessment method. The bacterial 16S rRNA gene sequence analysis of No.16 strain shows that it is most close to the standard strain of Rhodopseudomonas palustris with 97% of identity. Therefore, the No.16 stain is certain to be Rhodopseudomonas palustris, it is named as Rhodopseudomonas palustris W1.The research shows that strain W1 decolorize Reactive Black 5 by means of biological co-metabolism. Sodium lactate is the optimal additional carbon resource of the study, the optimal concentration is 2g/L. Ammonium chloride is the optimal nitrogen resource, the optimal concentration is 1g/L. Strain W1 has a adaptive and resistive capability of pH and salinity in environment. It can keep the higher activeness of decolorization and degradation under light anaerobic circumstance of pH 5~10, dark aerobic circumstance of pH 6~11 and circumstance of high salinity. Most of dyes can be decolorized by the stain. However, COD of wastewater is degraded with worse efficiency by strain W1, we can introduce photosynthetic bacteria/activated sludge process to improve the efficiency of COD degradation.According to the analysis of UV-Vis absorption spectrum and LC-MS spectrum, the decolorization mechanism of Reactive Black 5 is mainly that cracking reaction, which produce aromatic amine as an intermediate product, happen on the azo-bond of dyes. Decoloriztaion of Reactive Black 5 was first order kinetics when initial concentration of dye ranged from 50 to 500mg/L under light anaerobic condition. The correlation between specific decolorization rate and initial concentration of Reactive Black 5 can be interpreted by Michaelis-Menten model. The Michaelis constant Km=348.20mg/L and the maximum specific decolorization rate Vmax=80mg/(L.h).更多还原