多功能吸附材料—钛锰复合氧化物的制备及砷、铅吸附行为研究

发布时间：2018-01-25 21:47

本文关键词： 钛锰复合氧化物吸附 As(V) As(III) Pb 去除机理　出处：《中国科学院烟台海岸带研究所》2015年硕士论文　论文类型：学位论文

【摘要】：近几十年,重金属在工业生产中应用越来越广泛。伴随着重金属矿物开采、加工及应用,部分重金属进入水环境中,造成水体污染,严重影响了生态系统及人体健康安全。因此,水体重金属污染去除得到越来越多的关注。砷是一种自然环境中广泛存在的类重金属元素,毒性很大且具致癌性。砷在水溶液中通常以As(V)和As(III)两种形态存在,As(III)比As(V)有更高的毒性,且前者比后者更难以去除。铅是另一种在工业生产中广泛应用的重金属,对人体健康有严重危害,可导致多种疾病发生,特别是影响儿童智力发育。铅在水溶液中主要以二价阳离子形态存在。这两种重金属具有典型的代表性,它们的去除得到更多关注。与其他传统除砷、铅方法相比,吸附法是最有应用前景的一种方法。因为它操作简单、经济高效、无污泥产生且吸附材料可多次循环再生。但现有的吸附材料通常很难同时去除含砷和铅的污水,即很难同时去除含有阴离子型和阳离子型重金属污染物的污水。因此,开发新型、廉价、高效的除重金属吸附材料以降低水处理成本具有非常重要的意义。以研制能同时高效去除砷和铅的吸附材料为目的,本研究将钛氧化物对As(V)的高吸附性能与二氧化锰对Pb的高吸附性能及其对As(III)的氧化性能结合在一起,研制了一种多功能吸附材料——钛锰复合氧化物,并在材料制备、表征、砷和铅吸附性能及其去除机理方面开展了系统研究。通过上述研究,获得了以下主要成果:1.采用氧化还原/共沉淀一步合成法制备了钛锰复合氧化物,该吸附材料具有较大的比表面积(349.5 m2/g),发达的孔结构,含有丰富的表面金属羟基,主要以无定型形式存在。2.钛锰复合氧化物对As(V)和As(III)的吸附容量均很高,对As(III)和As(V)的最大吸附容量分别为107.0 mg/g和87.2 mg/g,表明该吸附材料对As(III)的去除效果更好。钛锰复合氧化物能快速同时去除溶液中As(V)和As(III),且能有效的将As(III)迅速氧化成As(V),可应用的p H范围比较宽,再生性能良好,可在实际生产应用中循环使用。3.As(V)与钛锰复合氧化物形成了内表面配合络合物,而As(III)的去除机理为氧化还原/吸附机制。As(III)被二氧化锰氧化成As(V)的同时,二氧化锰被还原溶解,导致在材料表面生成新的活性吸附位点,这可能是As(III)去除效果显著优于As(V)的主要原因。4.钛锰复合氧化物能快速去除溶液中的Pb,且对Pb有很好的吸附效果,特别是在低浓度条件下,对Pb的最大吸附容量为186.3 mg/g,可应用的p H范围比较宽,对Pb有很强的特异性选择,再生性能较好,具有良好的实用性。5.Pb与钛锰复合氧化物发生了化学吸附,在材料表面上形成了单齿单核或双齿单核的内配位络合物。
[Abstract]:In recent decades, heavy metals are more and more widely used in industrial production. With the mining, processing and application of heavy metal minerals, some heavy metals enter the water environment, resulting in water pollution. Therefore, the removal of heavy metal pollution in water has received more and more attention. Arsenic is a kind of heavy metal element widely existing in natural environment. Arsenic is highly toxic and carcinogenic in aqueous solution. And the former is more difficult to remove than the latter. Lead is another heavy metal widely used in industrial production, which has serious harm to human health and can lead to a variety of diseases. Lead mainly exists in aqueous solution as bivalent cations. These two heavy metals are typical and their removal has been paid more attention. And other traditional arsenic removal. Compared with the lead method, the adsorption method is the most promising method because of its simple operation and economic efficiency. No sludge is produced and adsorption materials can be recycled many times. However, it is often difficult for existing adsorption materials to remove arsenic and lead in wastewater at the same time. That is, it is difficult to remove both anionic and cationic heavy metal pollutants. It is very important to reduce the cost of water treatment by high efficiency adsorbents for removing heavy metals. The purpose is to develop adsorbents which can remove arsenic and lead efficiently at the same time. In this study, the high adsorption properties of titanium oxides for Aso V and manganese dioxide for Pb and oxidation properties for Aso II I) were combined. A kind of multifunctional adsorbent material, titanomanganese complex oxide, was developed, and the preparation, characterization, adsorption properties and removal mechanism of arsenic and lead were systematically studied. The main results are as follows: 1. Ti-Mn composite oxides were prepared by redox / coprecipitation one-step synthesis. The adsorption material has a large specific surface area of 349.5 m2 / g). Developed pore structure, rich surface metal hydroxyl groups, mainly in the form of amorphous form. 2. The adsorption capacity of titanium and manganese composite oxides for ASV) and As-III) are very high. The maximum adsorption capacities of As#en0# III and ASV) were 107.0 mg/g and 87.2 mg/g, respectively. The results show that the adsorption material has better removal efficiency of As-III, and the titanium-manganese complex oxides can rapidly remove both As-V and As-III from the solution at the same time. It can be used to oxidize AsN II I rapidly to AsHV, which can be used in a wide range of pH and has good regeneration performance. The complex complex on the inner surface is formed by using the compound oxides of titanium-manganese in the form of the compound oxides of titanium-manganese, which can be reused in practical production. However, the removal mechanism of Aso III is that of redox / sorption mechanism. Asao III) is oxidized to ASV by manganese dioxide), and manganese dioxide is reduced to dissolve at the same time. A new active adsorption site was formed on the surface of the material, which may be the main reason that the removal efficiency of As-III is significantly better than that of As-V) .4. Ti-Mn complex oxides can rapidly remove Pb from the solution. In particular, the maximum adsorption capacity of Pb is 186.3 mg / g at low concentration, and the pH range is relatively wide. It has strong selectivity for Pb, good regeneration performance and good practicability. 5. Chemical adsorption of Pb and Ti-Mn complex oxides has taken place. Monodentate mononuclear or didentate mononuclear internal coordination complexes are formed on the surface of the material.
【学位授予单位】：中国科学院烟台海岸带研究所
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ424;X703

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