【作者】 张婷婷；

【导师】 张蕾；

【作者基本信息】 辽宁大学 ， 分析化学， 2016， 硕士

【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。更多还原

【Abstract】 With the rapid development of economy, the human values more and more high about environment, such as environmental pollution, the most direct and polluting industries and related industrial products. Most dyes and dye intermediates are carcinogenic, teratogenic, mutagenic, toxic biological characteristics, human health and ecosystems are causing serious harm. Exploring dye degradation method has become a top priority.We studied the absorbing materials AB2O4 (A=Sr, Ba, Fe, B=Fe, Co) as a catalyst, microwave irradiation degradation dye wastewater (crystal violet, methyl violet, malachite green) was studied. The influence of calcination temperature of AB2O4, initial dye concentration, the amount of catalyst, pH value of the dye solution, the microwave power, microwave irradiation time, interfering ions and other factors on the degradation efficiency were studied. Through a series of analytical methods for degradation mechanism AB2O4 would be revealed.Magnetic ferrite SrFe2O4 is synthesized by sol-gel method and is used XRD, SEM and VSM methods to characterize. The results showed prepared SrFe2O4 has spinel structure, and with good magnetic properties. Crystal violet and methyl violet are as the target pollutants to judge the catalytic property of SrFe2O4. Optimum degradation conditions is:the calcination temperature of SrFe2O4 is 400℃, added SrFe2O4 mass fraction of 0.1%, and 50 mL 10mg L-1 crystal violet and methyl violet solution in a microwave reactor with output power 500 W, the degradation efficiency of the microwave radiation for 8 min could reach more than 80%. The reaction kinetics of CV/MV obeyed the apparent pseudo-first-order model. The reaction rate was 0.22 min-1 and 0.17 min-1, respectively. Radicals trapping studies revealed the holes (h+), hydroxyl radicals (·OH) and superoxide radical (·O2-) were involved as the main active species in the reaction.Magnetic ferrite BaFe2O4 is synthesized by citrate-nitrate combustion method and use XRD, SEM and VSM methods to characterize. The results showed prepared has spinel structure, and with good magnetic properties. Crystal violet is as the target pollutants to judge the catalytic property of BaFe2O4. Optimum degradation conditions is:the calcination temperature of BaFe2O4 is 800℃, added BaFe2O4 mass fraction of 0.06%, and 50 mL 10 mg L’1 crystal violet solution in a microwave reactor with output power 500 W, the degradation efficiency of the microwave radiation for 8 min could reach 90%. The reaction kinetics obeyed the apparent pseudo-first-order model. The reaction rate was 0.44min-1. Radicals trapping studies revealed the holes (h+) and superoxide radical (·O2-) were involved as the main active species in the reaction.Magnetic ferrite FeCo2O4 is synthesized by thermal decomposition method and use XRD, SEM and VSM methods to characterize. The results showed prepared FeCo2O4 has spinel structure, and with good magnetic properties. Malachite green is as the target pollutants to judge the catalytic property of FeCo2O4. Optimum degradation conditions is:the calcination temperature of FeCo2O4 is 600℃, added FeCo2O4 mass fraction of 0.2%, and 50 mL 20 mg L"1 malachite green solution in a microwave reactor with output power 500 W, the degradation efficiency of the microwave radiation for 8 min could reach 90%. The reaction kinetics obeyed the apparent pseudo-first-order model. The reaction rate was 0.13min-1. Radicals trapping studies revealed the holes (h+) and superoxide radical (·O2-) were involved as the main active species in the reaction.The results show that, MW/AB2O4 system applied to the degradation of dye can greatly reduce the degradation time and increase the rate of degradation. Also by ion chromatography and UV measurement results, the refractory organic dye molecules have been completely mineralized to inorganic ions and other harmless substances. The MW/AB2O4 system will not cause secondary pollution. The degradation efficiency is still above 80% after four times, reducing the waste of resources and damage to the ecological environment.更多还原