【作者】 黄富荣；

【导师】 尹华；

【作者基本信息】 暨南大学 ， 环境科学， 2004， 硕士

【摘要】 利用光合细菌作为生物吸附剂对废水中的铜、铬生物吸附进行了系统的研究。主要包括生物吸附剂的筛选、吸附性能、吸附动力学、脱附与再生、吸附机理及廉价培养等。 首先研究4株光合细菌R-01，R-02，R-03，R-04对Cu²⁺的生物吸附行为。结果表明，3株红螺菌R-01，R-02，R-04对20mg／L的Cu²⁺有较高的吸附率，其中R-04达99.1％，经初步鉴定该菌为红假单胞属（Rhodopseudomonas sp．）。在pH2、浓度为80mg／L Cu²⁺、35℃、微光厌氧吸附45min的最佳吸附条件下，R-04对Cu²⁺吸附率、吸附量分别达94％，48.03mg／g。菌体可以在多种碳、氮源中生长，但在不同的碳、氮源中培养的菌体对铜的吸附是不同的。 R-04对Cu²⁺的吸附动力学符合准二级动力学模型。应用Langmiur吸附模型和Freundlich吸附模型对菌体的吸附量与铜离子平衡浓度之间的关系进行描述，R-04对Cu²⁺的吸附均符合Langmiur吸附模型和Freundlich吸附模型，并且符合Langmiur吸附模型的程度更优。 比较分析了多种脱附剂对R-04菌体的脱附效果，EDTA和柠檬酸是较有效的洗脱剂，脱附率分别为86.4％、66.9％；无机酸及无机盐对菌体的脱附效果很差，脱附率在20％左右。菌体的再生性能不理想，尽管重复使用两次吸附性能下降不是很明显，但第三次之后吸附性能明显下降。 红外光谱表明，羟基峰位红移，吸附Cu²⁺后峰位移动为22cm^-1，吸附Cr⁶⁺后移动28cm^-1，其它峰没有漂移，并且峰形基本保持不变，说明吸附后菌体的主要成分及结构保持完整。原子力成像表明，吸附前胞外聚合物分散分布，吸附后胞外聚合物出现交联，形成一个新的二维网状结构，并且吸附Cu²⁺后的交联程度比吸附Cr⁶⁺高。X-射线衍射分析表明，菌体吸附Cu²⁺后没有形成新晶相，并且菌体部分晶相转变为非晶相。 生物吸附剂廉价培养的研究发现R-04可以在啤酒废水中正常生长，并且菌体去除铜的能力跟实验室培养的菌体相当。更多还原

【Abstract】 In this paper,the biosorption of copper.chromium in the waste water was studied comprehensively by using phytosysthetic bacteria. The research covers selection of biosorbents,capability of sorption,kinetics analysis,desorption and reuse,mechanism of biosorption and biosorbent cheap culture.Biosorption of copper ion by phytosysthetic bacteria was studied in the first place. Four strains of phytosysthetic bacteria were used as biosorbents to deal with Cu2+ in wastewater. It was shown that Rhodospirillum R-OI,R-02,R-04 had high biosorption capacities for copper ion, among which R-04 had the most excellent ability to adsorb copper and its removal rate could reach 99.1%, when the concentration of copper was 20mg/l. The optimal uptake conditions for R-04 were: pH=2,Cu2+80mg/l, 35 C,weak light and anaerobic for 45min.Under these conditions, the removal rate and the biosorption capacity could reach 94%,48.03mg/g,respectively. The bacteria could grow in many kinds of carbon and nitrogen sources, but the adsorption efficiency was different with different culture conditions.The kinetics analysis of copper onto the Rhodospirillum R-04 was investigated. The experimental results showed that the biosorption process followed the pseudo-second-order kinetics model. The sorption process of copper in determinated concentration was in accordance with both Langmuir and Freundlich isotherm, but better complied with Langmuir model.It was found that EDTA and citric acid were the effective eluants for the elution of adsorbed copper by R-04, the elution efficiency wrere 86.4%, 66.9%,respectively. Regeneration of R-04 was not satisfactory, although adsorbing performance did not decrease obviously after reusing twice. Adsorbing performance dropped greatly when it was reused third times.Infrared spectroscopy and atomic force microscopy techniques have been used to study the changes before and after biosorption of heavy metals by R-04. The IR spectrograms indicated that the apex of hydroxyl group(-OH) had a Einstein shift of 22cm-1 after adsorption of Cu2+,and that of Cr6+ was 28cm-1, the others did not shiftand the shapes of apices did not change in essence. All of these indicated that the main components and structure of strain remained integral. The FAM demonstrated that the extracellular biopolymer of R-04 was dispersive before adsorption, but conglutination appeared after adsorption of heavy metals and formed a new double dimensional reticulation structure. At the same time the greater degree of conglutination was observed for sorption of copper than chromium. The analysis of the X-ray diffraction spectra indicated that the bacteria did not form new crystal after the adsorption and some of the crystal of the bacteria had transformed into non-crystal.The research on the cheap substitute of biosorbent culture found that R-04 could grow normally in beer producing waste water and the strain cultured by this way had the same ability to adsorp copper with that which had been obtained in laboratory culture.更多还原