钴修饰炭材料的制备及其对典型PPCPs的降解

发布时间：2018-03-10 17:08

本文选题：有序介孔碳　切入点：活性炭　出处：《武汉工程大学》2015年硕士论文　论文类型：学位论文

【摘要】：药品与个人护理品(Pharmaceuticals and personal care products,PPCPs)作为一种新型有机污染物,近些年被环境学者们广泛关注,并且在水环境中各种PPCPs不断被检出。尽管PPCPs在水环境中检出的浓度较低,但由于其具有“假持续性”和生物累积性等特点,并且可以通过生物富集或食物链传递,对生态系统及人体存在潜在威胁。常规的水处理工艺对这类有机污染物不能很有效的去除,需进行探寻其他工艺对这类物质进行去除。近年来发展起来的以自由基氧化有机物的非均相Fenton氧化这一方法,是一种有效处理该类物质的方法。本文通过对选定的炭材料—活性炭和有序介孔碳进行钴修饰,采用类Fenton氧化法—钴和过硫酸盐体系对沙利度胺和硝酸咪康唑两种典型PPCPs进行降解去除研究,得到如下结论:(1)以软模板法合成的空白有序介孔碳(OMC)为载体,然后利用后浸渍—焙烧法制备出钴修饰有序介孔碳(Co/OMC),通过热重(TGA)、X-射线衍射(XRD)、N2吸附-脱附及透射电镜(TEM)等手段对OMC和Co/OMC进行表征结构特征。结果表明,制备OMC过程中除去模板剂F127在700℃条件下最佳,煅烧Co/OMC在600℃最佳;经过钴修饰后,低添加量的Co/OMC仍然具有良好的有序性和二维孔道结构,随着钴添加量的增加有序性降低;OMC比表面积从676 m2·g-1降低到652 m2·g-1,孔径变化不明显;Co/OMC中的钴粒子以Co2O3的形式存在,且在OMC基体上分散均匀。(2)使用Co/OMC活化过硫酸钠(PDS)对沙利度胺进行降解表明:Co/OMC在常温下能很好的活化PDS降解沙利度胺,随着温度的升高,其降解速率越快;室温25℃下,去除浓度为20 mg/L的沙利度胺溶液,在溶液初始pH值为3.0,PDS和Co/OMC投加量均为100 mg/L,经过120 min后,降解去除率可达97.6%;Co/OMC与PDS这一体系对沙利度胺的降解符合一级动力学模型;Co/OMC材料催化有良好的催化性能,使用三次仍具有较高的催化活性。(3)对预处理后的木质粉末活性炭(AC)进行钴修饰,研究了Co/AC-Cl材料和Co/AC-N材料的结构特点,通过广角XRD和N2吸附-脱附等手段表明,Co/AC-N材料比表面积较大,孔径稍大;而Co/AC-Cl材料中钴粒子会造成AC孔道堵塞;Co/AC-N材料中钴粒子以CoO和Co2O3的形式分布在AC表面,而Co/AC-Cl材料则以粒径较大的Co3O4形式分布。(4)通过使用Co/AC-N和Co/AC-Cl材料活化PDS对硝酸咪康唑进行降解去除,Co/AC-Cl材料降解硝酸咪康唑反应速率更快,但是钴溶出率较高,对环境有害,重复使用效果不佳,而Co/AC-N材料表现出较高的催化活性和较好的重复利用性。通过正交实验对影响Co/AC-N材料活化PDS降解硝酸咪康唑的因素进行了研究,结果表明对降解影响最大的因素是溶液初始pH值,降解去除浓度为50 mg/L硝酸咪康唑的最佳反应条件为:在室温条件下,溶液初始pH值为3.0,Co/AC材料投加量为500 mg/L,PDS投加量为200 mg/L,反应时间120 min后,去除率为97.2%。
[Abstract]:Pharmaceutical and personal care products (Pharmaceuticals and personal care products, PPCPs) as a new type of organic pollutants in recent years, environment by the attention of scholars, and various in water environment PPCPs has been detected. Although the concentration of PPCPs was detected in the water environment is low, but because of its "false persistence" and bioaccumulation etc, and can pass through biological enrichment or the food chain, and the ecological system and human potential threat. The conventional water treatment process on the removal of organic pollutants can not be very effective, need to explore other process for this type of material removal. The free radical oxidation of organic compounds by heterogeneous Fenton oxidation of this a method developed in recent years, is an effective method for treatment of such substances. Based on the selected co modified carbon materials and activated carbon and ordered mesoporous carbon, using Fe Nton oxidation of cobalt sulfate system and Study on removal of two kinds of typical PPCPs thalidomide and miconazole nitrate, we get the following conclusions: (1) the blank soft template method synthesis of ordered mesoporous Kong Tan (OMC) as the carrier, and then use after dipping roasting prepared cobalt modified ordered mesoporous carbon (Co/OMC), thermogravimetry (TGA), X- ray diffraction (XRD), N2 adsorption desorption and transmission electron microscopy (TEM) and characterized the structure characteristics of OMC and Co/OMC. The results showed that the preparation of the template was removed F127 best under the condition of 700 DEG C in the process of OMC, the best calcined Co/OMC at 600 DEG C after modification; cobalt, low amount of Co/OMC still has a good order and two-dimensional pore structure, with the addition of the order of cobalt decreased; OMC surface area from 676 m2 / g-1 reduced to 652 M2 - g-1, the change of pore size is not obvious; cobalt particles in OMC Co/ exists in the form of Co2O3, And on the substrate of OMC dispersion. (2) using Co/OMC (PDS) on activated persulfate degradation showed that Co/OMC thalidomide thalidomide to activate PDS to degrade very well at room temperature, with the increase of temperature, the degradation rate is faster; room temperature of 25 DEG C, removal of thalidomide concentration is 20 mg/L, in solution the initial pH value of 3 PDS and Co/OMC dosage was 100 mg/L, after 120 min, the degradation removal rate was 97.6%; the degradation of Co/OMC and PDS of the system of thalidomide with a kinetic model; Co/OMC material has good catalytic catalytic properties, catalytic activity three times still has high. (3) of powdered activated carbon after pretreatment (AC) was modified with cobalt, structural features of the Co/AC-Cl and Co/AC-N materials, through the wide angle XRD and N2 adsorption desorption method showed that the Co/AC-N material is larger than the surface area, pore size slightly larger; and Co The cobalt particle /AC-Cl material will cause AC pore blockage; cobalt particles in Co/AC-N material with CoO and Co2O3 in the form of distribution on the surface of AC and Co/AC-Cl materials with larger particle size distribution. The form of Co3O4 (4) by using Co/AC-N and Co/AC-Cl materials of activated PDS of miconazole nitrate reducing solution removal, Co/AC-Cl degradation miconazole nitrate faster reaction rate, but cobalt dissolution rate is higher, harmful to the environment, the repeated use of poor results, while the Co/AC-N materials exhibit higher catalytic activity and better reusability. Through orthogonal experiment of activated PDS miconazole nitrate on degradation effect of Co/AC-N materials were studied, the results show that the degradation the biggest factor is the initial pH value of solution, concentration of degradation and removal of the optimum reaction conditions of 50 mg/L miconazole nitrate: at room temperature, the initial pH value of solution was 3, Co/AC dosage was 500 mg/L When the dosage of PDS is 200 mg/L and the reaction time is 120 min, the removal rate is 97.2%.

【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52;TQ127.11

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