【作者】 蒋俊；

【导师】 李秀艳；

【作者基本信息】 华东师范大学 ， 环境科学， 2010， 硕士

【摘要】 环境激素被公认为“第三代环境污染物”。而壬基酚(NonylPhenol,简称NP)和双酚A (Bisphenol A,简称BPA),是其中有代表性的环境内分泌干扰物。生物降解是自然环境中消除NP和BPA污染最有效途径之一,因此,开展NP和BPA生物降解的研究具有重要的意义。本文对上海天山污水处理厂氧化沟的活性污泥进行驯化,从中分离纯化并筛选得到能分别以NP和BPA为唯一碳源和能源生长的降解菌株N1、N2、N3和B2,利用紫外分光光度法定量检测NP和BPA的残留率,主要采用正交设计探讨了其降解性能,选用Monod方程作为描述菌株降解动力学的模型。主要研究结果表明：(1)通过摇瓶实验并借助正交试验对菌株的降解条件进行了优化,N1降解NP最佳条件为：35℃,初始pH 5.5,无机盐培养液中NP起始浓度为10 mg／L,降解24 h,降解率达79.64%；N2降解NP最适条件为：30℃,初始pH 7.0,无机盐培养液中NP起始浓度为10 mg／L,降解24 h,降解率达71.04%；N3降解NP最好条件为：35℃,初始pH 5.5,无机盐培养液中NP起始浓度为20 mg／L,降解24 h,降解率达67.55%；B2降解BPA最优条件为：30℃,初始pH 7.0,无机盐培养液中BPA起始浓度为10 mg／L,降解24 h，降解率达78.68%。(2)在上述优化温度和初始pH条件下,分别对N1、N2、N3和B2在不同NP和BPA起始浓度下的降解反应过程进行动力学分析,该降解过程在底物浓度为5～40 mg／L时符合Monod方程,N1、N2、N3和B2的动力学参数Ks依次为4.32、4.66、5.11和8.36,μm依次为0.1778、0.1086、0.1823和0.1119。(3)对降解率最高的N1和B2进行菌种鉴定,根据菌株的16S rDNA序列同源性分析,再结合菌落和菌体形态以及生理生化特征,初步鉴定N1为Citrobacter sp.57(柠檬酸杆菌属一种),B2为Bacillus sp.Al-3(芽孢杆菌属一种)。这两株分别降解壬基酚和双酚A的细菌本研究为首次报道,具有一定的应用价值和推广潜力。更多还原

【Abstract】 Environmental hormone, was generally considered as the third generated environmental pollutants. NP and BPA were two representative EEDs. Biodegradation of NP and BPA was one of the most effective ways to remove NP and BPA in natural environment. Thus, it was an important meaning to conduct the research of biodegradation of NP and BPA. In this paper, bacterial strains designated as N1、N2、N3 and B2 were isolated, purified and sorted from acclimated activated sludge in oxidation ditch of Shanghai Tianshan Wastewater Treatment Plant with NP and BPA as the sole carbon and energy source respectively. The residual rate of NP and BPA was quantitative detected by uv spectrophotometry. The degrading characteristics were mainly discussed by orthogonal design. Monod equation was adopted as the kinetics model. The results mainly showed that:(1) The degrading conditions for strain N1、N2、N3 and B2 were optimized by tests in shaking flasks and orthogonal tests. The results showed that the optimum conditions for strain N1 degrading NP were 35℃, the initial pH 5.5, initial NP concentration 10 mg/L in salt medium, the degradation rate reached 79.64% in 24 h; the optimum conditions for strain N2 degrading NP were 30℃, the initial pH 7.0, initial NP concentration 10 mg/L in salt medium, the degradation rate reached 71.04% in 24 h; the optimum conditions for strain N3 degrading NP were 35℃, the initial pH 5.5, initial NP concentration 20 mg/L in salt medium, the degradation rate reached 67.55% in 24h; the optimum conditions for strain B2 degrading BPA were 30℃, the initial pH 7.0, initial BPA concentration 10 mg/L in salt medium, the degradation rate reached 78.68% in 24 h.(2) Based on the above optimal temperature and initial pH value, the kinetics analysis of strain N1、N2、N3 degrading NP and strain B2 degrading BPA under different initial NP and BPA concentrations respectively showed that the degradation reaction conformed to Monod equation when the initial substrate concentrations were 5～40mg/L and the kinetic parameters of Ks and um from Strain N1、N2、N3 and B2 for the model were 4.32、4.66、5.11、8.36 and 0.1778、0.1086、0.1823、0.1119, respectively.(3) Strain N1 and B2 were identified preliminarily as Citrobacter sp. and Bacillus sp. respectively according to their sequence analysis of 16S rDNA as well as morphological, physiological and biochemical characteristics. Such two strains with certain application value and the potential of extension were first reported.更多还原