酵母基复合型微球的制备及其废水处理应用

发布时间：2018-12-10 14:40

【摘要】：随着现代工业的迅速发展,生产过程中排出的有害重金属离子废水和生物难降解的印染废水日益增加。寻找较为廉价的废水净化材料,对其中有害重金属离子和染料分子的有效处理已成为环境保护中亟待解决的问题。目前废水的处理方式主要以催化和吸附为主,但是单一的方式无法达到低成本,高效率同时无二次污染等。因此,本文致力于针对废水处理开发一类经济、高效、环境友好型新材料,并运用多种测试方法和表征手段对其物理化学性能等进行探讨和研究。(1)水热法合成可控结构的Ti O2@酵母菌复合光催化剂。FE-SEM和EDS表明复合催化剂具很好的分散性且其核壳或草莓型结构可通过调节钛酸正丁酯的量来控制,XRD结果表明水热合成的Ti O2@酵母催化剂Ti O2为锐钛矿相。FT-IR结果表明催化剂的形成与酵母细胞表面化学官能团有关。沉降性能测试表明该复合物具有好的沉淀性能,有利于催化剂的分离回收。在光催化还原Cr(VI)水溶液中,Ti O2@酵母光催化剂表现出了较高的光催化活性,经过5次循环实验,可知Ti O2@酵母光催化剂有很好的可重复利用性能。(2)水热法合成Fe3O4,再通过静电自组装方法成功制备Fe3O4@酵母复合催化剂。各种表征分析方法表明:该复合催化剂保持了酵母原有的型貌特征,单分散性好,易分离。Fe3O4@酵母复合催化剂的形成机理与酵母表面的官能团有关。所合成催化剂应用于在固定床系统中处理阳离子染料亚甲基蓝。考察了染料初始浓度、流速、床层高度和p H对固定床吸附亚甲基蓝的影响,并对其进行了响应面分析,结果表明响应面法建立的模型可准确描述吸附过程,且浓度、流速、p H、浓度和p H的交互项、流速和p H的交互项、p H的平方效应显著。此外,对吸附过程进行了Thomas和Yoon-Nelson模型分析。结果表明,在初始浓度为100 mg/L、流速为5 m L/min、床层高度为3 cm、p H为11时吸附性能最好,Yoon-Nelson模型能更好的描述吸附过程。进行了再生实验,并探讨了再生机理,表明该铁系非均相Fenton氧化可有效实现Fe3O4@酵母复合微球的再生重复利用。本文制备的两种新型复合微球在材料设计中实现了将生物吸附性能和催化材料的催化性能进行整合,制备过程具有绿色环保、操作简单、反应温和、成本低廉等优点,所制备的复合催化剂可以较好地处理废水。
[Abstract]:With the rapid development of modern industry, the harmful heavy metal ion wastewater and the biodegradable printing and dyeing wastewater are increasing day by day. It has become an urgent problem to solve the problem of environmental protection to find cheap waste water purification materials and to deal with harmful heavy metal ions and dyestuffs effectively. At present, the main treatment methods of wastewater are catalysis and adsorption, but the single way can not achieve low cost, high efficiency and no secondary pollution. Therefore, this paper is devoted to the development of a new class of economic, efficient and environment-friendly materials for wastewater treatment. The physical and chemical properties of Ti O _ 2 @ yeast were studied by various test methods and characterization methods. (1) the controllable structure of Ti O _ 2 @ yeast composite photocatalyst was synthesized by hydrothermal method. FE-SEM and EDS showed that the composite catalyst had good properties. Good dispersion and its core-shell or strawberry structure can be controlled by adjusting the amount of n-butyl titanate, XRD results showed that the hydrothermal synthesis of Ti O _ 2 @ yeast catalyst Ti O _ 2 was anatase phase, and the FT-IR result showed that the formation of the catalyst was related to the chemical functional groups on the surface of yeast cells. The sedimentation property test shows that the composite has good precipitation performance and is beneficial to the separation and recovery of the catalyst. In photocatalytic reduction of Cr (VI) aqueous solution, Ti O 2 @ yeast photocatalyst exhibited high photocatalytic activity. The results showed that Ti O _ 2 @ yeast photocatalyst had good reusability. (2) Fe3O4, was synthesized by hydrothermal method and then successfully prepared by electrostatic self-assembly method. All kinds of characterization and analysis methods showed that the compound catalyst maintained the original form and appearance of yeast, had good monodispersity and was easy to be separated. The formation mechanism of Fe3O4@ yeast composite catalyst was related to the functional groups on the surface of yeast. The synthesized catalyst was applied to the treatment of cationic dye methylene blue in a fixed bed system. The effects of initial dye concentration, flow rate, bed height and pH on the adsorption of methylene blue in a fixed bed were investigated. The results showed that the model established by the response surface method could accurately describe the adsorption process, and the concentration and flow rate. The square effect of the interaction terms of pH, concentration and pH, the velocity of flow and the interaction term of pH, p H are significant. In addition, the adsorption process was analyzed by Thomas and Yoon-Nelson models. The results show that when the initial concentration is 100 mg/L, the flow rate is 5 mL / min, the bed height is 3 cm,p H and 11:00, the adsorption performance is the best, and the Yoon-Nelson model can better describe the adsorption process. The regeneration experiments were carried out and the regeneration mechanism was discussed. It was shown that the heterogeneous Fenton oxidation of the iron system could effectively realize the regeneration and reuse of Fe3O4@ yeast composite microspheres. In this paper, two new composite microspheres have been designed to integrate the biosorption properties with the catalytic properties of the catalytic materials. The preparation process has the advantages of green environmental protection, simple operation, mild reaction, low cost and so on. The prepared composite catalyst can better treat wastewater.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ426;X703

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