【作者】 郭燕；

【导师】 肖利平；

【作者基本信息】 湘潭大学 ， 环境工程， 2010， 硕士

【摘要】 从造纸厂IC厌氧反应器内的污泥中筛选出一株对直接耐晒黑19（C.I. Direct Black19,简称DB19）有高效降解能力的菌株,通过形态特征、生理生化及16S rDNA序列分析,初步鉴定为荧光假单胞菌（Pseudomonas fluorescens）,命名为Pf-6。采用序批实验,在35±2℃条件下,考察了Fe⁰对Pf-6菌降解DB19、活性艳蓝X-BR（C.I. Reactive Blue4,简称X-BR或RB4）、活性艳红X-3B（C.I. Reactive Red2,简称X-3B或RR2）及混合染料的影响及相关反应动力学;借助UV-vis、FT-IR等手段分析染料降解过程产物,初步探讨了Fe⁰/Pf-6菌联合体系降解3种染料的脱色机理。（1）Fe⁰/Pf-6菌联合体系处理DB19,比纯Pf-6菌、单独Fe⁰体系脱色率显著提高。厌氧条件下,3种体系脱色过程均遵循一级反应动力学,其反应速率常数k₁分别为55.4×10³ h¹、35.7×10³ h¹和14.3×10³ h¹。（2）Fe⁰/Pf-6菌联合体系处理100 mg/L的DB19脱色的适宜条件为:兼氧,初始pH为7.0,Fe⁰投加量为500 mg/L,Pf-6菌液接种量为5%。当DB19的初始浓度由100 mg/L增加到1500 mg/L,脱色速率常数k₁由63.8×10³ h¹减小到22.4×10³ h¹。（3）兼氧Fe⁰/Pf-6菌联合体系处理100 mg/L的X-BR,71 h后可实现约90%的脱色率,比纯Pf-6菌、单独Fe⁰体系分别高30%和40%;而处理100 mg/L的X-3B,55 h后即可实现约90%的脱色率,比其它两种体系脱色率高约60%。X-BR和X-3B在联合体系中的脱色过程均遵循一级反应动力学,其反应速率常数k1分别为31.1×10³ h¹和35.6×10³ h¹。（4）兼氧Fe⁰/Pf-6菌联合体系分别处理DB19、X-BR和X-3B 3种染料脱色后,系统内TTC-脱氢酶活性分别为40.98,37.07,45.26μgTF/（mL·h）,而纯Pf-6菌体系仅为16.53,12.23,19.80μgTF/（mL·h）,说明添加Fe⁰有助于提高兼氧微生物系统的脱氢酶活性,从而促进染料脱色。（5）UV-vis和FT-IR分析表明,在Fe⁰/Pf-6菌联合体系中,DB19、X-3B和X-BR主要通过偶氮键的断裂和蒽醌共轭结构的破坏实现脱色,含萘环和苯环结构等中间产物可得到进一步降解。（6）Fe⁰/Pf-6菌联合体系对三种染料形成的混合废水也有较好的脱色效果。在适宜条件下,当三种染料初始浓度均为40 mg/L,经55 h处理后,DB19、X-BR和X-3B的脱色率分别为88%、80%和75%。更多还原

【Abstract】 One bacterial strain with high degradation capacity for the dye- C.I. Direct Black19 (DB19) was isolated from anaerobic sludge in an Internal Circulation (IC) anaerobic reactor of a paper and pulp wasterwater treatment plant. The bacterium, which is named Pf-6, was primarily identified as Pseudomonas fluorescens through analysis results of its morphological, physiological and biochemical performances and 16S rDNA genetical sequence test. By batch experiments, the effect of zero-valent iron (Fe~0) on the biodegradation of DB19、C.I. Reactive Blue4 (X-BR or RB4)、C.I. Reactive Red2 (X-3B or RR2) and mixed pollutant composed of above three dyes, and kinetics of their decolorization in the Fe~0/Pf-6 combined system were investigated under the condition of mesophilic temperature 35±2℃. The decolorization process and intermediate products of these dyes in the Fe~0/Pf-6 combined system were preliminarily analysed by means of some methods such as UV-vis, FT-IR.(1) Compared with pure Pf-6 and single Fe~0 treatment systems, the decolorization effect of DB19 was significantly improved in the Fe~0/Pf-6 combined system. Under the anaerobic condition, the decolorization process of DB19 obeyed the first-order reaction dynamics in above three treatment systems. The dynamical constants k1 in the Fe~0/Pf-6 combined, pure Pf-6 and single Fe~0 systems were 55.4×10~3 h~1, 35.7×10~3 h~1 and 14.3×10~3 h~1 respectively.(2) When intial DB19 concentration was 100 mg/L, the optimum conditions of oxygen supplied、pH, Fe~0 dosage and Pf-6 inoculation volume for its decolorization in the Fe~0/Pf-6 combined system were facultative anaerobic, 7.0, 500mg/L and 5% respectively. Otherwise, the k1 decreased from 63.8×10~3 h~1 to 22.4×10~3 h~1 with increasing of initial DB19 concentration from 100 mg/L to 1500 mg/L.(3) When initial X-BR concentration and HRT were 100 mg/L and 71 h respectively, its decolorization rate was about 90% in the Fe~0/Pf-6 combined system under the facultative anaerobic condition, which were 30% and 40% higher than that in the pure Pf-6 and single Fe~0 systems respectively. However, the decolorization rate of X-3B in the Fe~0/Pf-6 combined system could also reach about 90% with initial dye concentration and HRT of 100 mg/L and 55 h respectively, which was 60% higher than that in the pure Pf-6 and single Fe~0 systems. Otherwise, both of the decolorization processes of X-BR and X-3B obeyed the first-order reaction dynamics and theirs dynamical constants k1 were 31.1×10~3 h~1 and 35.6×10~3 h~1 respectively in the combined system.(4) After these dyes– DB19, X-BR and X-3B were decolozied under the facultative anaerobic condition, the values of 2,3,5-triphenyl tetrazoliumchloride dehydrogenase activity (TTC-DHA) in the Fe~0/Pf-6 combined system could reach up to 40.98, 37.07, 45.26μgTF/(mL·h) respectively, while they were only 16.53, 12.23, 19.80μgTF/(mL·h) respectively in the pure Pf-6 system. It showed that, Fe~0 could effectively improve dehydrogenase activity under the facultative anaerpbic condition, which was benefit to promote dye decolorization in the Fe~0/Pf-6 combined system.(5) Based on analysis results of UV-vis and FT-IR, it indicated that, in the Fe~0/Pf-6 combined system, the decolorization of DB19, X-3B and X-BR were achieved mainly through fracture of azo bond and damage of anthraquinone conjugate structure respectively. Otherwise, some intermediate products with the structure of naphthalene ring and benzene during these dyes decolorization could also be partially degraded in the combined system.(6) During treatment of mixed dye wasterwater composed of DB19、X-BR and X-3B, certain decolorization effect could be obtained in the Fe~0/Pf-6 combined system. When initial each dye concentration and HRT were 40 mg/L and 55 h respectively, the decolorization rates of DB19, X-BR and X-3B were 80%, 75% and 47% respectively under the optimum conditions.更多还原