偶氮染料的微波诱导催化反应技术与降解机理

Azo dye containing an azo group is the most important chemical class of dyes and colorants in the textile industry, account for approximately 70% of organic dyes on the market. Azo dyes wastewater has the characteristic of high COD, large color and poor biodegradability. Microwave-induced catalytic technology can be effective in azo dyes wastewater treatment, though several fundamental scientific questions remain unclear. Based on the optimization in preparation method and related preparation conditions, homemade manganese ferrite nanoparticle will be synthesized in this study; microwave thermal effects and non-thermal effects in the Presence of catalysts will be studied to clarify the microwave induced catalysis mechanism; microwave induced catalytic degradationof typical azo dyes selected as model compound will be investigated to study their degradation kinetics and the main influencing factors, and establish the degradation dynamic models of the target compounds; the effect of catalyst, microwave, and other influencing factors on the degradation of the target compounds will be discussed, to obtain the optimal parameters in the catalytic reaction. According to the intermediate and final products identified and the data of reactive free radicals, the degradation pathways can be discussed in this study; the evaluation in catalyst stability and toxicity test before and after reaction will provide evidence for the safety and reliability of this technology. This study can be theoretical guidance and technical support for the practical application of microwave catalytic reaction.

偶氮染料是使用量最大的合成染料，其形成的废水COD值高、色度大、稳定而可生化性差。微波诱导催化技术可有效用于去除此类废水，但还存在一些基础科学问题仍然不清楚。本课题以自制的纳米铁酸锰为催化剂，通过催化剂制备方法的比选确定最优制备方法，研究催化剂的制备因素以优化其制备条件；研究催化剂的微波热效应和非热效应，以阐明微波条件下催化剂的催化作用机制；构建微波诱导催化反应体系，以典型偶氮染料为目标物，研究目标物的降解动力学及其主要影响因素，建立目标化合物的动力学模型；探讨催化剂、微波和其它影响因素对目标化合物的降解影响，获取催化反应技术运行的最佳工艺参数。鉴定目标化合物降解产物，并结合活性中间体研究数据，以探讨目标物的降解途径；通过探讨催化剂的稳定性和测试目标物反应前后毒性变化来评价微波催化反应处技术的安全性和可靠性，为该技术的实际应用提供理论指导与技术支撑。

本项目首先确定了纳米铁氧体(MnFe2O4、MgFe2O4 和CuFe2O4)及及其复合微波诱导催化剂(MnFe2O4-SiC、MgFe2O4-SiC、MnFe2O4-TiO2和MnFe2O4-diatomite和CuFe2O4/GAC)的制备方法；通过考察柠檬酸的含量、煅烧温度、载体的粒径大小、负载量等对催化剂活性的影响优化其制备条件，并对其微观结构和微波吸收能力进行表征；以自制的纳米铁氧体及复合材料为催化剂，建立了一整套微波诱导催化反应体系；研究了微波诱导催化剂对目标化合物的吸附等温曲线，探讨了目标化合物浓度、溶液pH等因素对目标物在催化剂上吸附的影响，建立目标化合物吸附动力模型；确定了目标化合物的反应级数，建立了目标化合物降解反应速率方程，并探讨反应动力学的影响因素；分析了微波的热效应和非热效应，阐明了微波催化的作用机制；通过GC-MS、LCMS和离子色谱，分析了目标化合物降解中间产物与最终产物，结合EPR数据，详细探讨了目标化合物的降解机理；构建了微波诱导降解-臭氧耦合技术，并应用于实际废水的处理研究，通过探讨催化剂的稳定性和测试目标物反应前后毒性变化来评价微波催化反应处技术的安全性和可靠性，为该技术的实际应用提供理论指导与技术支撑。