给水污泥中硅、铝和铁的回收及其衍生纳米材料的制备

发布时间：2018-04-22 00:28

本文选题：给水污泥 + 废物利用　；参考：《黑龙江大学》2015年硕士论文

【摘要】：给水厂每天都会排放大量的污泥,是沉淀池混凝沉淀产生的污泥,其中混凝剂和有机物对环境影响较大。中国每年大约产生1.5-2.4百万吨干污泥,该副产物一直以来被人们认为是废物,常常不经过任何处理直接排放到污水管道,进入自然环境,对水生生态环境影响较大。为了减少处理给水污泥产生的费用及避免污泥产生的二次危害,对其进行资源化利用已经备受关注。给水污泥的主要成分是黏土、腐殖质以及残存其中的混凝剂等,其中包含大量铁、铝和硅等无机组分。如果能够将这些无机组分回收提纯并加以利用,将会产生较多的环境效益,因此,如何科学合理地回收利用大量的污泥已成为非常受关注的问题。本文对焙烧后的给水污泥进行酸性提取,之后通过调节pH值得到高纯度的铝酸钠溶液,以其作为原料制备介孔氧化铝材料,对提取后产生的污泥废渣进行碱性提取,得到高纯度硅酸钠溶液,以其作为原料制备介孔二氧化硅材料,从而实现对给水污泥中的Si、Al成分进行回收,并制备了纳米铝基和硅基介孔材料。以铝酸钠为原料制备介孔氧化铝,制备得出比表面积为332.9m2/g,孔体积为0.52cm3/g,性质优良的介孔氧化铝。以硅酸钠为原料制备介孔二氧化硅,制备得出比表面积为1241.2m2/g,孔体积为1.2cm3/g,性质优良的介孔硅。以硅酸钠和铝酸钠为原料制备介孔硅铝氧化物,制备得出比表面积为743.4m2/g,孔体积为0.73cm3/g,性质优良的介孔材料。由于这些多孔材料具有丰富的表面官能团和多孔结构,使其可以应用在很多方面,如吸附、载体等。且在提取中产生的大量含铁废物可以进一步进行提取。使用污泥中提取剩余的含铁废物为原料,并利用提取的铁组分制备出磁性Fe3O4和γ-Fe2O3纳米粒子;再利用碱液提取的硅酸钠溶液与磁性纳米粒子混合,制备了分散性良好的Fe3O4@SiO_2和γ-Fe2O3@SiO_2磁性复合材料,二氧化硅层对磁性纳米粒子起到了很好的保护作用,避免磁性纳米粒子被氧化,同时保留磁性纳米粒子的磁响应性。Fe3O4@SiO_2和γ-Fe2O3@SiO_2磁性复合材料在包覆后磁性降低,但是磁性复合材料在液体中仍然可以快速分离。从材料红外表征580cm-1处的Fe-O和1080cm-1处的Si-O-Si吸收峰可见材料被二氧化硅成功包覆了一层20-150nm的保护层,Fe3O4@Si O2和γ-Fe2O3@SiO_2磁性复合材料表面具有多孔结构,具有较高的比表面积和孔体积分别为390.0m2/g(0.80cm3/g)和220.9m2/g(0.31cm3/g)。对Fe3O4@SiO_2和γ-Fe2O3@SiO_2磁性复合材料对活性红X-3B和亚硝酸钠的吸附性能进行研究,可见材料具有良好的吸附性。
[Abstract]:A large amount of sludge is discharged from the water supply plant every day, which is produced by coagulation sedimentation in the sedimentation tank, in which coagulants and organic compounds have a great impact on the environment. About 1.5-2.4 million tons of dry sludge is produced every year in China. This by-product has always been regarded as a waste, which is often discharged directly into the sewage pipe without any treatment and into the natural environment, which has a great impact on the aquatic ecological environment. In order to reduce the cost of sludge treatment and avoid the secondary harm of sludge, the reuse of sludge has been paid more and more attention. The main components of water sludge are clay, humus and residual coagulants, which contain a lot of inorganic components such as iron, aluminum and silicon. If these inorganic components can be recovered and purified and utilized, it will bring more environmental benefits. Therefore, how to recover and utilize a large amount of sludge scientifically and reasonably has become a very important issue. In this paper, acid extraction of feed water sludge after calcination was carried out. After adjusting pH value to high purity sodium aluminate solution, mesoporous alumina material was prepared by adjusting pH value, and alkaline extraction of sludge waste residue was carried out. The high purity sodium silicate solution was used as raw material to prepare mesoporous silica materials, so as to recover Si-Al from feed water sludge and to prepare nano-Al and Si-based mesoporous materials. Mesoporous alumina was prepared by using sodium aluminate as raw material. The specific surface area was 332.9 m2 / g, pore volume was 0.52cm3 / g, and the mesoporous alumina with excellent properties was obtained. Mesoporous silica was prepared by using sodium silicate as raw material. The mesoporous silicon with a specific surface area of 1241.2 m2 / g and pore volume of 1.2 cm 3 / g was obtained. Mesoporous silica-aluminum oxides were prepared by using sodium silicate and sodium aluminate as raw materials. The mesoporous materials with a specific surface area of 743.4 m2 / g and pore volume of 0.73 cm ~ 3 / g were prepared. Because these porous materials have abundant surface functional groups and porous structures, they can be used in many fields, such as adsorption, carrier and so on. And a large amount of iron-containing waste can be extracted further. The magnetic Fe3O4 and 纬 -Fe _ 2O _ 3 nanoparticles were prepared by using the iron components extracted from the sludge as raw materials, then the sodium silicate solution extracted from the alkaline solution was mixed with the magnetic nanoparticles. Fe3O4@SiO_2 and 纬 -Fe _ 2O _ 3 @ Sio _ 2 magnetic composites with good dispersion were prepared. Silica layer has a good protective effect on magnetic nanoparticles and prevents them from being oxidized. At the same time, the magnetic responsivity of magnetic nanoparticles. Fe3O4SiOs2 and 纬 -Fe2O3O3SOSiOst2 magnetic composites were decreased after coating, but the magnetic composites could still be separated rapidly in liquid. The visible materials at Fe-O and 1080cm-1 at 580cm-1 were successfully coated with silicon dioxide with a protective layer of 20-150nm, Fe _ 3O _ 4R _ 2O _ 2 and 纬 -Fe _ 2O _ 3R _ 2O _ 3 Sio _ 2 magnetic composite with porous structure. It has a high specific surface area and pore volume of 390.0 m2 / g 0.80 cm / g and 220.9 m2 / g 0.31 cm / g / g respectively. The adsorption properties of Fe3O4@SiO_2 and 纬 -Fe _ 2O _ 3r Sio _ 2 magnetic composites to active red X-3B and sodium nitrite were studied.
【学位授予单位】：黑龙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;TB383.1

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