粉煤灰、硅灰制备有序介孔材料及其有机染料去除性能研究

发布时间：2018-01-14 05:32

本文关键词：粉煤灰、硅灰制备有序介孔材料及其有机染料去除性能研究　出处：《中国地质大学》2017年博士论文　论文类型：学位论文

【摘要】：随着染料合成及印染工业的废水排放量和排放种类不断增加,由此引发的环境污染日益显著。介孔二氧化硅因其比表面积大、表面官能团丰富等优点,成为吸附剂和催化剂载体的不二之选。然而,目前受硅源价格影响,制备成本较高,未能实现大规模生产。寻找合适硅源制备廉价介孔材料,在环境治理方向有着广阔的市场前景。另一方面,粉煤灰和硅灰作为工业废弃物,长期得不到合理、有效的利用,造成资源浪费、环境污染等多重问题。本研究综合介孔材料以及粉煤灰、硅灰的行业背景,结合目前我国染料废水污染严重的现状,以粉煤灰和硅灰为廉价原料制备高效吸附剂和催化剂载体,去除印染废水中的有机染料。本论文以燃煤固体废弃物—粉煤灰为原料,在乙酸乙酯催化作用下,一步水热法成功合成球形含铝介孔分子筛Al-MCM-41;以硅铁冶炼副产物—硅灰为原料,采用新工艺设备快速制备三种不同形貌介孔二氧化硅,并探讨其他组成成分,反应温度,反应时间等条件对介孔材料形貌的影响。以阳离子染料亚甲基蓝为吸附对象,研究四种介孔材料吸附性能。除直接用作高效吸附剂,球形硅灰基介孔二氧化硅还可用作催化剂载体,通过负载双金属氧化物得到两种非均相芬顿催化剂,并以亚甲基蓝为降解对象,对合成催化剂的催化性能进行了系统评价。具体设计思路与创新点如下:(1)以燃煤固体废弃物粉煤灰为原料,采用一步水热法合成球形形貌含铝介孔分子筛Al-MCM-41,使介孔分子筛的工业化生产成为可能。所制备介孔分子筛对阳离子染料废水呈现高效吸附性,在染料废水治理领域有较大应用前景。(2)以硅金属或硅铁合金行业产生的工业冶炼副产物硅灰为原料,采用医学用高压灭菌设备为反应器,通过控制催化剂乙酸乙酯添加量,采用水热法快速合成三种不同形貌介孔二氧化硅,合成介孔二氧化硅粒子在微米级别且尺寸可调。(3)选择轻质、多孔、吸附能力强、比表面积大的球形硅灰基介孔二氧化硅为载体,通过负载铁-铜或者锰-铜双金属氧化物,开发了两种新型双组分非均相Fenton催化剂,用于染料废水的处理。对于Fe Cu/SF-S-MCM催化剂,负载的Fe2O3和CuO之间的存在协同效应可加速催化反应的进行。对于MnCu/SF-S-MCM催化剂,负载的Mn和Cu以尖晶石形式存在于CuMn2O4的特殊结构中,使其具有较好的吸附性能和催化性能。本论文主要得到以下结论:(1)以粉煤灰为原料,CTAB为表面活性剂,乙酸乙酯为催化剂,采用一步水热法成功合成具备蜂窝结构特征的球形形貌含铝介孔Al-MCM-41。单因素制备实验显示:乙酸乙酯添加量不仅影响介孔分子筛颗粒尺寸,而且对介孔分子筛结构有一定影响;晶化温度和晶化时间在一定程度上影响着颗粒的分散性和圆球度。通过单因素实验得到球形介孔吸附剂的最佳工艺条件:乙酸乙酯添加量为10 mL,晶化温度为60°C,晶化时间为12 h。(2)以硅灰为原料,CTAB为表面活性剂,采用新的工艺设备,快速合成介孔二氧化硅,将晶化时间由原来的48 h大大缩短至1.5 h。通过控制催化剂乙酸乙酯添加量,得到三种不同形貌介孔二氧化硅,同时研究发现乙酸乙酯添加量不仅影响产品形貌还影响介孔材料有序性。采用单因素实验设计方案考察硅灰/CTAB摩尔比、体系水含量、晶化温度、晶化时间以及外加无机盐五个因素对介孔二氧化硅形貌的影响,通过以上实验因素调节介孔二氧化硅颗粒形貌和尺寸。(3)静态吸附实验讨论了溶液初始pH值,吸附平衡时间,溶液初始浓度以及吸附温度对四种吸附剂的影响。实验结果表明,溶液pH值的升高有利于四种吸附剂对亚甲基蓝的吸附,且均在pH为10.0时达到最大吸附量。在相同浓度下,三种硅灰基介孔二氧化硅在30 min达到吸附平衡,快于Al-MCM-41吸附剂(120 min)。四种吸附剂的吸附量随亚甲基蓝初始浓度的升高而增大,直至趋于吸附平衡。数据模拟表明,四种吸附剂对亚甲基蓝的吸附过程均符合拟二级动力学模型;吸附过程更符合Langmuir模型,为单层吸附;吸附热力学研究表明,吸附反应为自发、放热过程,反应过程中混乱程度减小。(4)以球形硅灰基介孔二氧化硅为载体,负载铁-铜或者锰-铜双金属氧化物,开发两种新型双组分非均相(类)Fenton催化材料。XRD和BET多孔性能测试表明两种新型催化剂均保留了介孔二氧化硅基体材料的MCM-41介观结构。XPS结果显示,FeCu/SF-S-MCM复合催化材料中Fe和Cu元素分别以+3价和+2价的形式存在于Fe2O3和CuO金属氧化物中;而MnCu/SF-S-MCM复合催化材料中Mn和Cu分别以+3价和+2价的形式存在于CuMn2O4尖晶石结构中。通过改变Fe/Cu、Mn/Cu摩尔比例,制备多种不同金属氧化物负载比例的复合催化材料并确定最佳配比。(5)探讨体系反应条件对亚甲基蓝降解效果的影响。降解实验结果表明:同时加入催化剂FeCu/SF-S-MCM和H2O2的体系,在光照反应45 min后,亚甲基蓝降解率可达98.38%;而同时加入MnCu/SF-S-MCM催化剂和H2O2,亚甲基蓝降解率略低,为96.51%。同时对比了相同实验条件下,基体材料SF-S-MCM对亚甲基蓝的降解率仅为50%左右,说明基体材料固载的双金属氧化物可大大提高降解效率。因此,本实验中亚甲基蓝的降解是催化剂、氧化剂(双氧水)以及紫外光照射共同作用的结果。(6)经单因素实验得出亚甲基蓝染料废水降解的最佳工艺条件。以FeCu/SFS-MCM为催化剂,当亚甲基蓝初始浓度为250.0 mg/L,催化剂投加量为0.50 g/L,H2O2投加量为0.3 mL,光照反应45 min后MB降解率可达99.31%,随着亚甲基蓝初始浓度的升高降解率有所降低,FeCu/SF-S-MCM催化剂在pH值为5.0-9.0的范围内均表现出较好的催化性能。对于MnCu/SF-S-MCM催化剂,当亚甲基蓝初始浓度为250.0 mg/L,催化剂投加量为0.50 g/L,H2O2投加量为0.5 m L,反应45min后降解率可达98.22%。随着亚甲基蓝初始浓度的升高,降解率有所降低。MnCu/SF-S-MCM催化剂在pH为3.0-9.0的范围内均表现出较好的催化性能,大大拓宽pH使用范围。
[Abstract]:With the wastewater emissions and emission type synthesis and dyeing increasing, which caused the environmental pollution becomes more and more significant. Mesoporous silica due to its large surface area, abundant surface functional groups has become the choice of adsorbent and catalyst carrier. However, affected by the current price of silicon source, the manufacturing cost is high, failed to achieve large-scale production. To find suitable silicon source for preparing cheap mesoporous materials, has a broad market prospect in environmental governance. On the other hand, fly ash and silica fume as industrial waste, long-term lack of reasonable and effective use, resulting in a waste of resources, multiple problems of environmental pollution. The study of dielectric porous material and fly ash, silica fume, industry background, combined with present situation of dye wastewater pollution in China is serious, with fly ash and silica fume as cheap raw materials for the preparation of highly efficient adsorbent and catalyst carrier, to In addition to organic dyes in dyeing wastewater. The coal solid waste - fly ash as raw materials in ethyl acetate catalyzed by one step hydrothermal synthesis of spherical aluminum containing Al-MCM-41 mesoporous molecular sieve; in ferrosilicon smelting by-product of wollastonite as raw materials, using new technology and equipment of three different morphologies of mesoporous silica quickly preparing, and discuss other components, reaction temperature, reaction time and other factors to influence the morphology of mesoporous materials. The cationic dye methylene blue adsorption research object, four kinds of mesoporous materials. The adsorption performance is directly used as high efficiency adsorbent, spherical silica based mesoporous silica can be used as a catalyst carrier, two a heterogeneous catalyst by Fenton supported bimetallic oxides, and methylene blue as the degradation object, the catalytic performance of the catalysts for the synthesis of a systematic evaluation of specific design ideas and innovation. Points are as follows: (1) coal solid waste fly ash as raw materials, synthesis of spherical morphology containing mesoporous molecular sieve Al-MCM-41 by one-step hydrothermal method, the mesoporous molecular sieve production possible. The preparation of mesoporous molecular sieve, adsorption of cationic dye wastewater has great application prospect in dye the wastewater treatment field. (2) produced by metal or silicon ferrosilicon alloy industry smelting by-product silica as raw materials, using medical autoclave reactor, by controlling the adding amount of ethyl acetate catalyst, the rapid synthesis of three different morphologies of mesoporous silica hydrothermal synthesis of mesoporous silica particles can be adjusted in micron level and size. (3) choose light, porous, strong adsorption capacity, large surface area of spherical silica based mesoporous silica as the carrier, through the load of iron - copper or copper - manganese double metal oxide, development Two novel two-component heterogeneous Fenton catalyst for dye wastewater treatment. The Fe Cu/SF-S-MCM catalyst, the synergetic effect between Fe2O3 and CuO load can accelerate the reaction. For the MnCu/SF-S-MCM catalyst, the special structure of Mn and Cu load with spinel form in CuMn2O4, which has adsorption performance and good catalytic performance. This paper obtained the following conclusions: (1) using fly ash as raw materials, CTAB as surfactant, ethyl acetate as catalyst by one-step hydrothermal method successfully synthesized with cellular morphology of aluminum spherical mesoporous Al-MCM-41. structure characteristics of the single factor experiment showed that the preparation of ethyl acetate amount not only affects the mesoporous molecular sieve particle size, but also has a certain influence on the structure of mesoporous molecular sieve; crystallization temperature and time have some influence on the particle dispersion and ball Degrees. Through the single factor experiment, the optimum process conditions of spherical mesoporous adsorbent obtained: ethyl acetate was added to 10 mL, the crystallization temperature of 60 C, the crystallization time was 12 h. (2) with wollastonite as raw material, CTAB as surfactant, using new technology equipment, rapid synthesis of mesoporous oxide two silicon, the time of crystallization from the original 48 h greatly shortened to 1.5 h. by controlling the added amount of ethyl acetate catalyst, obtained three different morphologies of mesoporous silica, the study also found that ethyl acetate addition products not only affect the morphology also affected the ordered mesoporous material. The influences of /CTAB molar ratio of silica fume by single factor experimental design, crystallization temperature the water content of the system, and influence the crystallization time and adding inorganic salts of five factors on the morphology of mesoporous silica particles, adjusting the size and morphology of mesoporous silica through the above experimental factors. (3) the static adsorption experiment is discussed. The initial pH value of solution, adsorption time, initial concentration of solution and the effect of temperature on the adsorption of four kinds of adsorbent. The experimental results show that the pH value of the solution increased to four kinds of adsorbents on the adsorption of Ya Jiaji blue, and when the pH is 10 the maximum absorption capacity. At the same concentration, three kinds of silica fume based on mesoporous silica reached adsorption equilibrium in 30 min, faster than the Al-MCM-41 adsorbent (120 min). Four increase of adsorption amount increased with the initial concentration of Ya Jiaji blue, to reach adsorption equilibrium data. Simulation results show that four kinds of adsorbents on the adsorption process of Ya Jiaji blue are in line with the quasi two level dynamic model; the adsorption process is more accord with the Langmuir model for monolayer adsorption; adsorption thermodynamics research showed that the adsorption reaction is exothermic, spontaneous process, the degree of confusion in the reaction process decreases. (4) with spherical silica based mesoporous silica as the carrier two, loaded with iron Copper or copper - manganese - double metal oxides, the development of two novel two-component heterogeneous (class) Fenton catalyst.XRD and BET porous performance test showed that two new catalysts were retained.XPS MCM-41 mesoscopic structure of mesoporous silica matrix material. The results show that Fe and Cu elements in FeCu/SF-S-MCM composite catalytic materials respectively. In Fe2O3 and CuO metal oxides to the +3 price and +2 price form; while Mn and Cu MnCu/SF-S-MCM composite catalytic materials were performed with a +3 price and +2 price exists in the form of CuMn2O4 spinel structure. By changing the molar ratio of Fe/Cu, Mn/Cu, catalytic composite material preparation of different metal oxides and to determine the proportion of the load the best proportion (5). To investigate the effects of reaction conditions on the system of methylene blue degradation. The degradation experiment results show that the addition of catalyst FeCu/SF-S-MCM and H2O2 system, in the light of the reaction after 45 min sub The degradation rate of methyl blue was 98.38%; while adding MnCu/SF-S-MCM and H2O2 catalyst, the degradation rate of Ya Jiaji blue is slightly lower, as compared to those of 96.51%. under the same experimental conditions, SF-S-MCM matrix materials on the degradation rate of Ya Jiaji blue is only about 50%, indicating that the dual metal oxide matrix materials supported can greatly improve the degradation efficiency. Therefore, degradation Ya Jiaji blue in this experiment is the catalyst, oxidant (hydrogen peroxide) as well as the result of joint action of UV irradiation. (6) the optimum conditions of single factor experiments of Ya Jiaji blue dye wastewater degradation. With FeCu/SFS-MCM as catalyst, when Ya Jiaji blue initial concentration was 250 mg/L, adding 0.50 g/L catalyst, H2O2 the quantity is 0.3 mL, MB light degradation rate is up to 99.31% after 45 min reaction, with Ya Jiaji blue initial concentration increased the degradation rate decreased, FeCu/SF-S-MCM catalyst in the pH value of 5.0-9. 0 the range showed good catalytic performance for MnCu/SF-S-MCM catalyst, when the initial concentration of methylene blue was 250 mg/L, adding 0.50 g/L catalyst, the dosage of H2O2 is 0.5 m L, after reaction of 45min degradation rate was up to 98.22%. with increasing the initial concentration of methylene blue, the degradation rate decreased in.MnCu/SF-S-MCM catalyst pH is in the range of 3.0-9.0 showed good catalytic performance, greatly broaden the application range of pH.

【学位授予单位】：中国地质大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X703;O643.36;TB383.4

【相似文献】