【作者】 周倩倩；

【导师】 蔡伟民；

【作者基本信息】 上海交通大学 ， 环境工程， 2011， 硕士

【摘要】 酚类化合物是原型质高毒类物质,具有三致效应,对一切生命个体都有明显的毒害作用。作为一种常见的工业污染物,苯酚广泛存在于造纸、炼油、炼焦、农药、化工、医药合成等行业的工业废水中,未经处理的含酚废水对人类生存环境造成了严重的威胁。生物法是一种成本低廉、二次污染较小的工业废水处理方法,在含酚工业废水处理中正由传统混合微生物处理技术向纯培养微生物处理技术转型的阶段。在课题组前期研究工作中发现,好氧颗粒污泥对于模拟苯酚废水具有较好的降解特性,为研究其苯酚降解机理进而强化其苯酚降解效能,本文采用分离纯化技术从好氧颗粒污泥中筛选分离得到了两株高活力苯酚降解菌,经23Sr DNA测序鉴定,菌株为热带假丝酵母（Candida tropicalis）属。研究结果表明:菌株A1和A3均有比较高的苯酚耐受能力,在以苯酚为唯一碳源的培养条件下能够耐受1 750 mg/L和2 000 mg/L的苯酚;同时也均有高效的苯酚降解率,在接菌量为3%,温度为30℃、pH值为6.85、装液量为100 mL /250 mL、恒温振荡速度120 r/min的最佳降酚工艺条件下,A1可使初始浓度为1 000 mg/L的苯酚24 h降解率达到95%以上,而A3可达到100%的降解率。葡萄糖对微生物降解苯酚具有协同作用和底物竞争关系,投加量≤1.0 g/L;以硝酸铵为外加氮源,经济有效;虽然配制的模拟废水中本来已含有相当量的无机微量元素,但去除培养基中的微量元素液对苯酚降解亦有较大的影响,这说明微量元素对于微生物来说是必不可少的。同时,在保证充分的溶解氧的情况下,进行热带假丝酵母降解苯酚的本征动力学研究,通过试验数据拟合得到了该菌株的Haldane菌体生长动力学方程参数为:热带假丝酵母A1菌株——最大比生长速率μX, max=0. 409h^-1,苯酚半饱和常数K_S=41.37mg/L,苯酚抑制常数K_i= 387.41mg/L;其相应的苯酚降解动力学参数为:生长相关系数A =0.4387,非生长相关系数, B =0.0003h ^-1;热带假丝酵母A3菌株——最大比生长速率μX, max= 0. 418h^-1,苯酚半饱和常数K_S=74.69mg/L,苯酚抑制常数K_i=432.38mg/L;其相应的苯酚降解动力学参数为:生长相关系数A=0.4872,非生长相关系数B=0.0031h^-1。从而得出该菌株有良好的工程应用价值。更多还原

【Abstract】 Phenol is present in the wastewater of many industries, such as paper making, petroleum refining, coking, pesticide, medicine synthesis and chemical engineering, et al. The phenol-containing wastewater without being treated has caused a serious threat to our environment. Among the common ways of phenol removal treatments, the biological methods are always preferable because of its lower cost and less possibility of a secondary pollution. Presently, the biological treatment technology is undergoing a transition from mixed-culture treatment to pure-culture treatment.In this paper, two kinds of the highly-active phenol degrading bacterial strains were isolated from the aerobic granular sludge through a traditional microorganism breeding technology, and identified as Candida tropicalis according to the 23Sr DNA sequence analysis. While phenol is presented as the sole carbon source, the two bacterial strains （A1 and A3）, which were selected to be the most effective ones, could endure a phenol concentration up to 1 750 mg/L and 2 000 mg/L, respectively. With the inoculum amount 3%,temperature 30℃,pH 6.85,liquid volume in flask 100 mL /250 mL and rate of shaking incubator 120 r/min, the degradation rate of the phenol solution （1 000 mg/L） achieved by A1 and A3 after 24 h could be as high as 95% and 100%, respectively.The kinetics of cell growth of Candida tropicalis at dissolved oxygen condition were investigated. Haldane’s equation was adopted to describe the kinetics at 30℃and pH=6.85: Candida tropicalis A1——μX, max= 0. 409h^-1, K_S=41.37mg/L, K_i=387.41mg/L.Phenol consumption kinetics was associated to the cell growth kinetics as: A=0.4387, B=0.0003h^-1; Candida tropicalis A3——μX, max=0. 418h^-1, K_S=74.69mg/L, K_i=432.38mg/L. Phenol consumption kinetics was associated to the cell growth kinetics as: A=0.4872, B =0.0031h^-1. These showed its high good feasibility and engineering value.更多还原