【作者】 李佩悦；

【导师】 雷绍民；

【作者基本信息】 武汉理工大学 ， 矿物加工工程， 2009， 硕士

【摘要】 随着科学技术与工业的发展,受污染的水资源越来越严重地威胁着人类的健康和生存质量。任何单一的废水处理技术都不能满足越来越高的排放要求。多技术综合处理生活废水、工业废水成为当今水处理的主流技术。借助光催化反应技术已成为研究的主要领域之一。传统光催化是在悬浮体系下应用的,具有易失活、难以分离回收并产生二次污染等问题。本研究制备一种密度小于1、化学性质稳定、在水介质中漂浮且不散失的光催化剂载体,在载体上复合TiO₂,制备出新型光催化材料,并用来降解选矿废水及机理探讨是本文的主要目的。研究内容包括:1.选择几种特定物质,以组分A、B、C、D为原料,制备Si-Al-Ca-C结构多孔轻质材料。详细研究了影响多孔轻质材料物化性能的因素。在制备配方探索性研究基础上分别作了单因素条件试验和正交选优实验,筛选出多孔轻质材料最佳制备工艺条件为:组分A含量为10%、组分B含量为40%、组分C含量为10%、组分D含量为40%、粘结剂CMC（工业级CMC-Na）含量为15%（占组分总质量的百分数）、800℃焙烧2h。该多孔轻质基体材料在水介质中漂浮时间为42h,散失率为0.65%,体积密度为0.98kg/m³,比表面积为2.5039m²/g,孔隙率为0.0032mL/g,抗压强度为2.64MPa。材料孔道分布均匀广泛,形状规则,孔径最小约5um,最大约100um,90%的孔径在20～60um之间。2.以含羟肟酸类捕收剂模拟选矿废水为降解对象,主要考察了各种因素对材料基体复合纳米TiO₂晶体膜的光催化性能影响。基体表面与TiO₂溶胶复合5次,键合温度为700℃,焙烧2h后即为Si-Al-Ca-C基体复合纳米TiO₂光催化新材料。在pH=3.0±0.1时,对四种羟肟酸类捕收剂的降解率依次为:N-羟基邻苯二甲酰亚胺（97.06%）＞水杨羟肟酸（86.32%）＞苯甲羟肟酸（84.06%）＞2-羟基-3萘甲羟肟酸（73.58%）。连续使用10次后,基体表面TiO₂负载量只有少量损失、降解率略有下降,与使用一次时进行比较,降解率下降了两个百分点,质量损失了10^-4g。应用研究表明,该材料是一种可高效循环利用的新型光催化材料。3.研究探讨了N-羟基邻苯二甲酰亚胺光催化降解动力学及机理,结果表明该反应符合Langmuir-Hinshelwood动力学方程。降解反应速率常数与N-羟基邻苯二甲酰亚胺废水溶液初始浓度成正比;当初始浓度为为20 mg·L^-1时,反应速率常数k最大,为0.0097 min^-1。研究结果表明:相同降解条件下,降解率高低一方面取决于光催化材料吸附氧化性能,另一方面取决于待降解有机物的分子结构,分子量大小。分子结构越复杂,分子量越大的有机物越难降解。复杂分子结构或大分子量有机物的降解是一个逐步光催化氧化分解,使分子链断开的过程,中间产物的氧化需要更大的能量和更长的氧化时间才能彻底实现矿化。更多还原

【Abstract】 With the development of science and industrial technology, polluted water is much more threatting to human health and quality of life. Any single wastewater treatment technology can not satisfied with the increasing requirement of emissions. More comprehensive treatment technology of domestic wastewater and industrial waste water becomes the mainstream of today’s water treatment technology. The aid of photocatalytic reaction technology becomes one of the major areas of study. There are many disadvantages by use of aqueous suspensions of TiO₂ in practical applications, such as easily deactivated, agglomerated, difficultly separated, and will produce secondary pollution. The main purpose of the paper was to develop a kind of photocatalyst carrier, which density is less than 1, chemical properties are stable and can float in aquatic phase with no dissipate, can compound TiO₂ on the substract and develop a novel photocatalytic materials, and can be used to the degradation of beneficiation wastewater as well. The research contents are as follows:1. A multi-porous lightweight materials of Si-Al-Ca-C structure prepared by chosing representative mass: ingredient A、B、C and D. The influence factors of phychemical properties. of multi-porous lightweight materials has been researched in detail. On the basis of exploratory study of the preparation of the prescription, These condition experiments of single factor and orthogonal were respectively investigated for multi-porous lightweight materials. The results shown that the best formula for making multi-porous lightweight materials are ingredient A 10 percent, B 40 percent, C 10 percent, D 40 percent and adhesives 15 percent calcined in 800℃for 2 hours. This light multi-porous material can floatable in aquatic phase for 42 hours,dissipation rate 0.65 percent and bulk density 0.98kg/m³. the specific surface area of the material 2.5039m²/g, the hole rate 0.0032mL/g and compressive strength 2.64Mpa. The uniformly and extensively distribution rate of pore pathway and regular shape, the minimum aperture for 5um and the maximum for 100um, and range from 20 to 60 um 90 percent for most them . 2. Many factors that effecting the photocatalysis activity have been researched in detail with hydroxamic acid which be used as a floatation collector. composited nano-crystal film of titanium onto surface of the substrate and coated for 5 times calcined temperature 700°C and then will become a novel photocatalytic materials which have Si-Al-Ca-C structure. When pH 3.0±0.1, the degradation rates to four kinds of hydroxamic acid are as follows: N-Hydroxyphthalimide （97.06 percent） > Salicylhydroxamic acid （86.32 percent） > Benzohydroxamic acid （84.06 percent） > 2-hydroxy-3-naphthyl hydroximic acid （73.58 percent）. The loading of TiO₂ of matrix substrate had a small loss and degradation rate declined slightly for recycled 10 times, compared with used once, degradation rate dropped two percentage points and quality loss for 10^-4 g. Research shown that this material is a novel photocatalytic material which can be efficiently recyled.3. The photodegradation reaction kinetics of N-hydroxyphthalimide has been studied. The experiment shown that the reaction accords with the kinetics equation of Langmuir-Hinshelwood. The reaction rate constant is proportional to initial concentration of N-hydroxyphthalimide. when the initial concentration 20 mg·L^-1, the rate constant k for the most 0.0097 min^-1.The investigation result shown: rate of degradation depends on two facts that one is absorbition oxidation capability of photocatalytic material,and another is the structure of molecule and molecular weight of organic matter that will be degraded on the same degradation condition. The more complex structure and heavy weight of organic matter ,the more difficult to be degraded. It is a gradually oxidized process that molecular chain of complex molecular structure or heavy molecular weight’s degradation, as well as much more energy needs and oxidized time to degradated the secondary products of the organics.更多还原