四氧化三铁基复合材料的制备及其在水处理中的应用研究

发布时间：2018-01-16 06:39

本文关键词：四氧化三铁基复合材料的制备及其在水处理中的应用研究　出处：《青岛科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着人口的增长和工业的发展,污染问题特别是水污染问题已经成为世界性的难题。水污染主要是指废水中污染物的浓度超过一定的浓度,严重影响着生态环境和人体健康。其中最主要的是重金属离子(镉、铬、铜、汞、镍离子等)污染和有机染料(甲基蓝、刚果红和罗丹明B等)的污染。传统的水处理方法有化学沉淀法、离子交换法、膜渗透法和光催化氧化法等,但由于其成本较高和处理效果不理想,因此不适合在工业生产中使用。吸附法因操作简便、高效率和低能耗等优点常用于水处理。传统的吸附剂较多,比如黏土、活性铝,但是吸附速率和吸附能力较低,不是很常用。由于可控孔结构、高的比表面积、大的孔体积和疏水性,活性炭常被应用于水处理中,但由于密度较小,易造成水溶液二次污染。近年来,金属氧化物和金属基复合物被应用于水处理,表现出了良好的吸附性能。本论文研究的是四氧化三铁基复合材料在水处理中的应用。四氧化三铁分别与活性炭、镁铝双层氢氧化物复合,研究了所得产物对水溶液中重金属离子Cr(VI)和有机染料(甲基蓝、刚果红和罗丹明B)的吸附情况。具体研究内容如下:1、本实验通过简单的水热法,运用硬模剂制备了以油酸钠和六水氯化铁(FeCl3×6H2O)为原料的四氧化三铁和碳复合物(Fe_3O_4@C),其中Fe_3O_4颗粒分别有序和无序的嵌入到碳层中,探究此样品对Cr(VI)和有机染料的吸附能力。实验结构表明:温度、pH和表面羟基密度等因素对Cr(VI)的吸附产生影响。由吸附动力曲线知,Fe_3O_4@C对Cr(VI)的初始吸附速率较快,大约为23.88 mg g-1 min-1;由吸附等温曲线知,在308 K,pH在4.8~5.8范围内,Fe_3O_4@C对Cr(VI)的最大吸附可达1100 mg g-1。上述数据比以往报道都要高,说明Fe_3O_4@C对Cr(VI)有很强的吸附能力。但是对于有机染料的吸附,Fe_3O_4@C复合物的吸附能力很差,12小时后吸附初始浓度的1%~5%。2、以苹果皮、香蕉皮和橘子皮为碳源(C),与六水氯化铁混合,通过浸泡-煅烧的方法制备Fe_3O_4@C复合材料,探究了该产物对Cr(VI)和不同有机染料的吸附能力。通过此简便方法制备出的三种不同结构的Fe_3O_4@C磁性复合材料,铁磁性较强(4 emu g-1),对Cr(VI)和有机染料都具有强的吸附能力(达到几百mg g-1),并且具有良好的循环再利用性(85%)。3、以硝酸铝和硝酸镁为前驱体,制备Mg-Al-双层金属氢氧化物(LDH),然后运用水热法制备Fe_3O_4颗粒,最后,在搅拌的作用下将Mg-Al-双层金属氢氧化物和Fe_3O_4复合,取得Fe_3O_4@Mg-Al-LDH复合材料。探究对废水中有机污染物和重金属Cr(VI)的吸附性能。由吸附等温曲线知,Fe_3O_4@LDH对Cr(VI)的最大吸附量大约为900 mg g-1。通过对甲基蓝、刚果红和罗丹明B等有机染料的吸附发现,Fe_3O_4@LDH对有机染料的吸附能力极强,1小时后有机染料溶液可变为无色,吸附量可达90%。
[Abstract]:With the development of population growth and industrial pollution, especially water pollution has become a worldwide problem. Water pollution mainly refers to the concentration of pollutants in wastewater exceeds a certain concentration, serious impact on the ecological environment and human health. The most important is the heavy metals (cadmium, chromium, copper, mercury, nickel ion pollution etc.) and organic dyes (methylene blue, Congo red and Rhodamine B) pollution. Chemical precipitation water treatment of traditional method, ion exchange method, membrane permeation and light catalytic oxidation, but because of its high cost and the treatment effect is not ideal, it is not suitable for use in industrial production in the adsorption method has the advantages of simple operation, high efficiency and low energy consumption etc. commonly used in water treatment. The adsorbent is more, such as the traditional clay, activated aluminum, but the adsorption rate and adsorption capacity is low, is not very common. Because of the controllable pore structure, high specific The surface area, large pore volume and hydrophobicity of activated carbon is often used in water treatment, but because the density is small, easy to cause two pollution water solution. In recent years, metal oxides and metal matrix composite is used in water treatment, showed good adsorption performance. The research of this thesis is the application of Fe3O4 composites in water treatment. The Fe3O4 respectively with activated carbon, magnesium hydroxide composite double, studied the products of heavy metal ions in aqueous solution of Cr (VI) and organic dyes (Jia Jilan, Congo red and Luo Danming B) adsorption. The specific contents are as follows: 1, through this experiment a simple hydrothermal method, were prepared using sodium oleate and six water using ferric chloride (FeCl3 * 6H2O mould agent) and Fe3O4 carbon composite materials (Fe_3O_4@C), in which Fe_3O_4 particles were embedded into the ordered and disordered carbon layer, this kind of inquiry The Cr (VI) and organic dye adsorption capacity. The result shows that the temperature factors, pH and surface hydroxyl density of Cr (VI) affected by adsorption. The dynamic adsorption curve of Cr (Fe_3O_4@C, VI) the initial adsorption rate is fast, about 23.88 mg by g-1 min-1; adsorption isotherm curve, at 308 K, pH in the range of 4.8~5.8, Fe_3O_4@C of Cr (VI) and the maximum adsorption was 1100 mg g-1. the above data are higher than previously reported, Fe_3O_4@C of Cr (VI) has a strong adsorption ability. But for the adsorption of organic dyes, the adsorption capacity of the Fe_3O_4@C complex is very poor 12 hours after the initial concentration, adsorption of 1%~5%.2 in apple peel, banana peel and orange peel as the carbon source (C), mixed with six aqueous ferric chloride, preparation of Fe_3O_4@C composite materials by the method of soaking - calcining system, explores the product of Cr (VI) and different organic dye adsorption ability through this simple. Square Three different structures of Fe_3O_4@C magnetic composite materials were prepared, strong magnetic iron (4 EMU g-1), Cr (VI) and organic dyes have strong adsorption capacity (up to hundreds of Mg g-1), and has the good recycling of (85%).3, using aluminum nitrate and magnesium nitrate the precursor, preparation of Mg-Al- layered double hydroxides (LDH), and then use the hydrothermal synthesis of Fe_3O_4 particles. Finally, under the action of stirring Mg-Al- double metal hydroxide and Fe_3O_4 composite, Fe_3O_4@Mg-Al-LDH composite materials. Research on wastewater organic pollutants and heavy metals Cr (VI) adsorption properties by adsorption isotherm. Curve, Fe_3O_4@LDH of Cr (VI) and the maximum adsorption capacity of about 900 mg g-1. by methylene blue adsorption of Congo red and Luo Danming B and other organic dyes, Fe_3O_4@LDH adsorption capacity of organic dyes is extremely strong, 1 hours after the organic dye solution variable For colorless, the amount of adsorption is up to 90%.

【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;X703

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