锆、铁氧化物改性活性炭纤维的制备及其除磷性能的研究

发布时间：2019-02-12 07:37

【摘要】：磷是一种动植物和人体必需的营养元素,具有十分重要的生理功能。然而,随着工业生产和人类活动日益加剧,过量的磷进入水体将导致藻类等迅速繁殖,造成水体富营养化,对生态环境造成严重威胁。因此,磷污染越来越受到人们的关注。目前,主要的含磷废水处理方法有化学沉淀法、生物法以及吸附法。吸附法是一种在水处理中广泛应用的技术,它具有处理设备简单、运行可靠、不易产生二次污染等优点。选用价格成本低、制备方法简单、吸附容量大以及容易脱吸附再生的吸附剂一直是国内外专家研究的重点。铁氧化物及锆氧化物具有很强的磷吸附能力,且具备性能稳定、价格低廉、环境友好等优点。活性炭纤维(ACF)具有巨大的比表面积,发达的孔隙结构和稳定的化学性质,是一种性能显著的环境友好材料,被广泛应用于水污染处理技术中。本研究拟采用共沉淀法,用锆、铁氧化物对活性炭纤维表面进行改性,制备出一种新型除磷吸附剂(ACF-ZrFe),以实现磷的高效去除。本文综合运用单因素实验与正交实验对ACF-ZrFe的制备条件进行优化,研究了吸附反应条件(吸附剂投加量、初始磷浓度、反应温度、溶液p H、干扰离子)对ACF-ZrFe的除磷性能的影响;考察了影响ACF-ZrFe的再生效率的因素;同时利用环境扫描电镜(ESEM)、傅里叶变换红外光谱分析(FT-IR)以及X射线光电子能谱分析(XPS)对吸附剂表面性质进行了探究。主要结论如下:(1)用共沉淀法合成了锆、铁氧化物的活性炭纤维除磷吸附剂,实验表明ACF-ZrFe具有良好的磷吸附性能。(2)运用正交法优化了ACF-ZrFe的制备条件,该最佳制备条件为:锆铁摩尔比为7:3,浸渍液中锆铁总浓度为0.1 mol/L,超声处理时间为10 min。(3)ACF-ZrFe的静态吸附实验表明:在其他反应条件一定的情况下,ACF-ZrFe的投加量增加、磷初始浓度的增加以及温度的升高均能使其对磷的单位吸附量增加。p H对ACF-ZrFe的磷吸附反应具有重要影响。NO3-、SO42-、F-和Cl-等共存阴离子对ACF-ZrFe吸附磷酸盐有一定抑制作用,其作用的强弱顺序为:F-NO3-Cl-SO42-。(4)ACF-ZrFe的磷吸附反应等温曲线符合Langmuir模型,准二级反应动力学模型可较好描述ACF-ZrFe的磷吸附过程。(5)HNO3、Na OH以及Na Cl这三种溶液对ACF-ZrFe均具有一定的再生效果,当脱吸附时间16 h,脱吸附溶液的浓度为0.1 mol/L时,这三种溶液对ACF-ZrFe再生效果的影响强弱顺序为:Na OHNa ClHNO3。(6)ACF-ZrFe对磷的吸附机制主要是阴离子配位体交换和静电吸附作用。
[Abstract]:Phosphorus is an essential nutrient for animals, plants and human bodies, and has very important physiological functions. However, with the increasing of industrial production and human activities, excessive phosphorus into the water will lead to rapid growth of algae, resulting in eutrophication of water, and pose a serious threat to the ecological environment. Therefore, people pay more and more attention to phosphorus pollution. At present, the main treatment methods of phosphorus-containing wastewater are chemical precipitation method, biological method and adsorption method. Adsorption method is a widely used technology in water treatment. It has the advantages of simple treatment equipment, reliable operation and not easy to produce secondary pollution. The selection of adsorbents with low cost, simple preparation method, large adsorption capacity and easy desorption and regeneration has been the focus of domestic and foreign experts. Iron oxide and zirconium oxide have strong phosphorus adsorption ability, and have the advantages of stable performance, low price, environment friendly and so on. Activated carbon fiber (ACF), with its large specific surface area, developed pore structure and stable chemical properties, is a kind of environment-friendly material with remarkable properties. It is widely used in water pollution treatment technology. In this study, a new phosphorus removal adsorbent (ACF-ZrFe) was prepared by modifying the surface of activated carbon fiber with zirconium and iron oxides by co-precipitation method. In this paper, single factor experiment and orthogonal experiment were used to optimize the preparation conditions of ACF-ZrFe. The adsorption reaction conditions (adsorbent dosage, initial phosphorus concentration, reaction temperature, solution pH) were studied. The influence of interference ions on the phosphorus removal performance of ACF-ZrFe; The factors affecting the regeneration efficiency of ACF-ZrFe were investigated and the surface properties of the adsorbent were investigated by (ESEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The main conclusions are as follows: (1) activated carbon fiber (ACF) with zirconium and iron oxides was synthesized by coprecipitation method. The experimental results show that ACF-ZrFe has good phosphorus adsorption properties. (2) the preparation conditions of ACF-ZrFe were optimized by orthogonal method. The optimum preparation conditions are as follows: the molar ratio of zirconium to iron is 7: 3, the total concentration of iron and zirconium in the impregnation solution is 0.1 mol/L, and the ultrasonic treatment time is 10 min. (3) ACF-ZrFe. The increase of the dosage of ACF-ZrFe, the increase of initial phosphorus concentration and the increase of temperature can increase the unit adsorption amount of phosphorus. P H has an important effect on the phosphorus adsorption of ACF-ZrFe. Co-existing anions such as F- and Cl- can inhibit phosphate adsorption by ACF-ZrFe in the order that F-NO _ 3-Cl-SO _ 42-. (4) the isotherm curves of phosphorus adsorption of F-NO _ 3-Cl-SO _ 42-. (4) ACF-ZrFe accord with Langmuir model. The quasi-second-order reaction kinetic model can better describe the phosphorus adsorption process of ACF-ZrFe. (5) HNO3,Na OH and Na Cl have some regeneration effect on ACF-ZrFe, and the desorption time is 16 h. When the concentration of the desorbed solution was 0.1 mol/L, the effect of the three solutions on the regeneration of ACF-ZrFe was in the order that the adsorption mechanism of phosphorus by: Na OHNa ClHNO3. (6) ACF-ZrFe was mainly anionic ligand exchange and electrostatic adsorption.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;TQ424.1

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