吸波材料与微波辐射协同降解染料的过程与机制研究

发布时间：2018-01-12 11:10

本文关键词：吸波材料与微波辐射协同降解染料的过程与机制研究　出处：《辽宁大学》2016年硕士论文　论文类型：学位论文

【摘要】：近年来,随着经济的快速发展,人类对环境的重视度越来越高。而在环境污染中,大部分直接与工业和工业产品的污染有关。多数染料及染料中间体都具有致癌、致畸、致突变效应,生物毒性大的特点,对人类的健康和生态系统都造成严重的危害。探索染料的降解方法,已经成为当务之急。本论文研究了自制吸波材料AB204(A=Sr,Ba,Fe,B=Fe,Co)作为催化剂,微波照射协同作用(MW/AB2O4)降解染料废水(结晶紫、甲基紫、孔雀绿)的作用效果,考察了AB204的煅烧温度、染料初始浓度、催化剂加入量、染料溶液的pH值、微波输出功率、微波辐射时间、干扰离子等因素对降解效率的影响,确定了实验的最佳条件,并通过一系列的分析方法对AB204的降解机理进行揭示。采用溶胶-凝胶(sol-gel)法合成磁性铁氧体SrFe2O4,并用XRD,SEM和VSM等方法对所得SrFe2O4进行表征,结果表明制得尖晶石结构的SrFe2O4,并且具有很好的磁性。选择染料污染物-结晶紫和甲基紫为目标污染物,研究MW/SrFe2O4体系对结晶紫和甲基紫的降解效果。MW/SrFe2O4协同降解染料的最佳降解条件为：SrFe2O4的煅烧温度是400℃,加入SrFe2O4的质量分数为0.1%,对50 mL 10 mg L-1的结晶紫和甲基紫溶液在微波输出功率500 W,微波辐射8 min后的降解效率能达到80%以上。降解动力学实验结果表明：MW/SrFe2O4协同降解结晶紫／甲基紫反应符合准一级动力学模型,反应速率常数分别为0.22 min-1和0.17 mmin-1。采用自由基捕获实验和荧光实验的方法得出MW/SrFe2O4协同降解结晶紫和甲基紫的实验过程中,产生的活性物质主要是超氧自由基,空穴和羟自由基。它们能够氧化染料,使染料快速降解成对环境无害的无机离子。采用柠檬酸盐-硝酸盐燃烧法合成磁性铁氧体BaFe2O4,并用XRD,SEM和VSM等方法对所得BaFe2O4进行表征,结果表明制得尖晶石结构的BaFe2O4,并且具有很好的磁性。选择染料污染物-结晶紫为目标污染物,研究MW/BaFe2O4体系对结晶紫的降解效果。MW/BaFe2O4协同降解结晶紫的最佳降解条件为：BaFe2O4的煅烧温度是800℃,加入BaFe2O4的质量分数为0.06%,对50 mL 10mg L-1的结晶紫溶液在微波输出功率500 W,微波辐射8min后的降解效率能达到90%。降解动力学实验结果表明：MW/BaFe2O4协同降解结晶紫反应符合准一级动力学模型,反应速率常数可达到0.44 min-1。采用自由基捕获方法得出MW/BaFe2O4协同降解结晶紫的实验过程中,产生的活性物质主要是超氧自由基和空穴。它们能够氧化染料,使染料快速降解成对环境无害的C02,H20和一些无机离子。采用热分解法合成磁性铁氧体FeCo2O4,并用XRD,SEM和VSM等方法对所得FeCo2O4进行表征,结果表明制得尖晶石结构的FeCo2O4,并且具有很好的磁性。选择染料污染物一孔雀绿为目标污染物,研究MW/FeCo2O4体系对孔雀绿的降解效果。MW/FeCo2O4协同降解孔雀绿的最佳降解条件为：FeCo2O4的煅烧温度是600℃,加入FeCo2O4的质量分数为0.2%,对50 mL 20 mg L-1的孔雀绿溶液在微波输出功率500 W,微波辐射8 min后的降解效率能达到90%。降解动力学实验结果表明：MW/FeCo2O4协同降解结晶紫反应符合准一级动力学模型,反应速率常数可达到0.13 min-1。采用自由基捕获实验得出MW/FeCo2O4协同降解孔雀绿的实验过程中,产生的活性物质主要是超氧自由基和空穴。它们能够氧化染料,使染料快速降解成对环境无害的CO2,H2O和一些无机离子。结果研究表明,MW/AB2O4协同作用降解染料,从传统的几个小时,缩短到现在的几分钟,大大缩短了降解时间,提高了降解速率。此外通过离子色谱、紫外测定结果可知,难降解的染料有机分子已被完全矿化为无机离子等无害物质,几乎没有中间产物产生,不会造成二次污染。同时通过外加磁场可将AB204进行回收利用,而且催化剂的循环利用次数达到四次后的降解效率依然在80%以上,减少了资源的浪费,减少了对生态环境的破坏。
[Abstract]:In recent years, with the rapid development of economy, human beings on the environment are paying more and more attention. In environmental pollution, the most direct and industrial products and industrial pollution. The majority of dyes and dye intermediates are carcinogenic, teratogenic, mutagenic effect, characteristics of biological toxicity, causing serious harm to human the health and ecological system. To explore the degradation methods of dyes, has become a pressing matter of the moment. This paper studies the self-made microwave absorbing materials AB204 (A=Sr, Ba, Fe, B=Fe, Co) as catalyst, microwave irradiation synergy (MW/AB2O4) degradation of dye wastewater (crystal violet, methyl violet, malachite green) effect was investigated the calcination temperature of AB204, initial dye concentration, catalyst dosage, pH value of dye solution, microwave power, microwave radiation time, interfering ions and other factors on the degradation efficiency of the influence, determine the optimal experimental conditions, and through The degradation mechanism analysis of a series of methods of AB204 are revealed. By using sol gel (sol-gel) method for the synthesis of magnetic ferrite SrFe2O4, and XRD, SEM and VSM methods were used to characterize the obtained SrFe2O4, results show that the prepared spinel structure of SrFe2O4, and has a very good choice. The magnetic dye pollutants - crystallization purple and violet as the target pollutant, the optimal degradation conditions of.MW/SrFe2O4 degradation effects of MW/SrFe2O4 system on crystal violet and violet synergistic degradation of dyes as the calcination temperature of SrFe2O4 is 400 DEG C, concentration of SrFe2O4 was 0.1%, 50 mL 10 mg L-1 crystal violet and methyl violet solution in the microwave output power is 500 W, degradation the efficiency of 8 min after microwave radiation can reach more than 80%. The experimental results show that the degradation kinetics of MW/SrFe2O4 synergetic degradation of crystal violet / methyl violet was consistent with pseudo first order kinetic model of reaction The rate constants were 0.22 min-1 and 0.17 mmin-1. by free radical trapping experiments and fluorescence experiments that MW/SrFe2O4 co degradation of crystal violet and violet in the main active substance is produced superoxide radical, hydroxyl radical and hole. They can oxidation dyes, inorganic ion dye fast degradation into nontoxic. Using citrate nitrate combustion synthesis of magnetic ferrite and BaFe2O4, XRD, SEM and VSM methods were used to characterize the obtained BaFe2O4, results show that the prepared spinel structure of BaFe2O4, and has a very good choice. The magnetic crystal violet dye pollutants as the target pollutant, the degradation effect of crystal violet on.MW/BaFe2O4 the MW/BaFe2O4 system of the synergistic degradation of crystal violet for optimal degradation conditions: the calcination temperature of BaFe2O4 is 800 DEG C, concentration of BaFe2O4 is 0.06% to 50, mL 10mg Crystal violet solution L-1 in the microwave output power of 500 W, the degradation rate of 8min after microwave radiation can reach the experimental results of 90%. degradation kinetics showed that MW/BaFe2O4 co degradation of crystal violet was consistent with pseudo first order kinetic model, the reaction rate constant can reach 0.44 min-1. by free radical trapping method to obtain the MW/BaFe2O4 synergistic degradation of crystal violet in the course of the experiments. The main active substance is produced superoxide radical and hole. They can make rapid degradation of oxidation dyes, dye into nontoxic C02, H20 and some inorganic ions. The decomposition of magnetic ferrite and FeCo2O4, XRD, SEM and VSM were used to the FeCo2O4, the results show that the as prepared the spinel structure of FeCo2O4, and has a good selection of magnetic. A malachite green dye pollutants as target pollutants, research on the system of MW/FeCo2O4 effect on the degradation of malachite green. The optimal degradation conditions of MW/FeCo2O4 synergetic degradation of malachite green as the calcination temperature of FeCo2O4 is 600 DEG C, concentration of FeCo2O4 was 0.2%, 50 mL 20 mg malachite green solution on L-1 in the microwave output power is 500 W, can reach 90%. degradation dynamics experimental results show that the degradation rate of 8 min after microwave radiation: MW/FeCo2O4 synergistic degradation of Crystal Purple was consistent with pseudo first order kinetic model, the reaction rate constant can reach 0.13 min-1. capture experiment of MW/FeCo2O4 synergetic degradation of malachite green by free radical, the main active substances are produced superoxide radical and hole. They can make rapid degradation of oxidation dyes, dye into nontoxic CO2, H2O and some inorganic ions. The results of study showed that the synergetic effect of MW/AB2O4 degradation, from a few hours to traditional, now shortened to a few minutes, greatly shorten the time of degradation. The high rate of degradation. The results showed that ion chromatography, UV dye, organic molecules refractory has been completely mineralized to inorganic ions and other harmful substances, almost no intermediate products produced, will not cause two pollution. At the same time by the external magnetic field AB204 can be recycled, and the number of recycling catalyst to degrade after four times the efficiency was still above 80%, reduce the waste of resources, reduce the damage to the ecological environment.

【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X788;O643.36

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