【作者】 周新革；

【导师】 长山；

【作者基本信息】 内蒙古师范大学 ， 材料物理与化学， 2010， 硕士

【摘要】 能源的枯竭、环境污染的不断加剧是我们全人类所面临的重大问题。目前国内外学者对废水处理方法做了大量的研究工作,在众多处理方法中,吸附法由于处理量大,反应时间短,无毒害物质生成,是目前较为理想的废水脱色方法。近年来,介孔TiO2由于具有优良的光学、电学、以及光催化性能,使其在水处理、空气净化、太阳能电池、催化剂载体、生物材料等方面表现出广阔的应用前景而备受瞩目。另外,由于介孔TiO2具有较大的比表面积、介孔孔容等特点,可以作为一种很好的吸附材料,然而在废水处理中将介孔TiO2作为吸附剂却未见报道。本论文围绕介孔TiO2材料的制备与应用展开了研究。在合成出介孔材料并加以表征之后,也研究了其对一些主要环境污染物的吸附性能,以期能在环境治理方面能得以应用,为环境的可持续发展做出贡献。本论文以十六烷基三甲基溴化铵(CTAB)为模板剂,采用水热法制备了具有优良可见光光催化活性和吸附性能的介孔TiO2材料,研究了制备条件对介孔TiO2光催化活性的影响,并首次探究了其对六价铬离子、染料甲基橙、氟离子的吸附性能,结果表明:所制备的介孔TiO2为不规则的球状形貌,其最可几孔径为5.2 nm,孔容为0.33 cm3·g-1,比表面积为161.2 m2·g-1。介孔TiO2对Cr(Ⅵ)的吸附性能比非介孔TiO2明显优越,且其吸附速率符合Bangham吸附速率方程;随着Cr(Ⅵ)浓度的增大,介孔TiO2对Cr(Ⅵ)的吸附量增大并逐渐趋于饱和;其最大吸附量为33.9 mg·g-1。介孔TiO2对甲基橙的吸附性能明显优于非介孔的TiO2,其极限吸附量为454.5 mg·g-1,属于放热吸附。吸附量也随着甲基橙溶液pH值的升高而降低,但降低的幅度不明显。甲基橙在介孔TiO2上的吸附可用Langmuir和Freundlich等温方程来描述。介孔TiO2对甲基橙的吸附主要是由介孔TiO2和甲基橙界面的静电力和氢键同时作用引起的。介孔TiO2对F-表现出了很好的去除效果,其最大吸附量为27.0 mg·g-1。当氟初始浓度为10 mg·L-1时,吸附率达90%,处理后的水F-含量符合饮用水的水质标准。更多还原

【Abstract】 Both energy depletion and environment pollution problems are becoming more and more serious to people in the world. Up to now, extensive studies have been performed for the treatment of wastewater, and many kinds of water treatment methods have been developed. Among these methods, adsorption is an ideal method for the treatment of wastewater due to its large removal ability, short reaction time, easy operation,and low cost. In recent years, due to its versatility in optical, electrical, and photochemical properties, TiO2 has been used in many different applications, including photocatalysts, sensors, photovoltaics, biomaterials, photocatalysts, solar cells, etc. In addition,mesoporous TiO2 is a promising adsorbent for its high surface area and large pore volume. On the other hand, extensive studies on the adsorption properties of mesoporous TiO2 have not been performed so far.In this paper, mesoporous TiO2 was synthesized and its adsorption capacities for several pollutants in industrial wastewater were investigated, so as to provide a more reliable theoretical data for the treatment of wastewaters.Mesoporous TiO2 was synthesized by hydrothermal method using cationic surfactant cetyltrimethylammonium bromide (CTAB) as the template with Ti(SO4)2 as Ti precursor, effects of different reaction conditions on the photocatalytic performance for methyl orange of the samples were discussed and its adsorption capacities for Cr(Ⅵ), and F- were investigated for the first time. The as-prepared mesoporous TiO2 are non-regular spherical particles and they possess a mesoporous structure with a pore diameter of 5.2 nm, pore volume of 0.33 cm3·g-1, and a surface area of 161.2 m2·g-1. When calcined at 400°C, the sample shows a surface area of 134.4 m2·g-1 and a pore diameter of 4.5 nm, and possess the best photocatalytic activity.The adsorption capacity of mesoporous TiO2 for Cr(Ⅵ) is considerably higher than that of non-mesoporous TiO2; the adsorption rate of Cr(Ⅵ) on the mesoporous TiO2 fits well with the Bangham equation. In the low concentration region, the adsorption capacity for Cr(VI) linearly increases with the increase of initial concentration of Cr(VI); and then the increase is retarded in the high concentration region. The maximum adsorption capacity of the mesoporous TiO2 for Cr(VI) is determined to be 33.9 mg·g-1.The adsorption ability of mesoporous TiO2 for is obviously superior to non-mesoporous TiO2. The adsorption capacity for methyl orange decreases with temperature incresment, showing that the adsorption of methyl orange on mesoporous TiO2 is exothermic. However, the adsorption for methyl orange is slightly influenced by pH of the solutions. The methyl orange adsorption data can be well depicted using Langmuir and Freundlich isotherms and the maximum adsorption capacity is estimated to be 454.5 mg·g-1 from Langmuir isotherm. The study on adsorption mechanism suggests that methyl orange is adsorbed on mesoporous TiO2 via electrostatic attraction and hydrogen bond formation.Compared to non-mesoporous TiO2, the mesoporous TiO2 exhibits better removal ability for F- with the maximum adsorption capacity of 27.0 mg·g-1. When the initial concentration of F- is 10 mg·L-1, the adsorption percentage of F- reaches as high as 90%, and the concentration of F- in treated water decreases to a value that is quite lower than the standard for drinking water.更多还原