纳米四氧化三铁技术去除水中六价铬的研究进展

文章介绍了水体中六价铬的来源与分布,概述了六价铬的吸附技术,着重介绍了纳米四氧化三铁技术去除水体中六价铬的研究进展,并对该技术的研究前景作了展望。     

纳米级四氧化三铁回收水中铅离子实验

采用共沉淀法制备了纳米级四氧化三铁,考察pH值、温度对铅吸附的影响及吸附动力学和吸附等温模型.结果表明,准二级动力学方程能更好地描述纳米级四氧化三铁对铅的吸附动力学过程,反应分为快速吸附阶段、慢速吸附阶段和吸附平衡阶段.pH对四氧化三铁吸附铅的过程有着明显的影响,pH过低会导致四氧化三铁对铅的吸附量降低.温度会影响四氧...     

纳米级四氧化三铁回收水中铅离子实验

采用共沉淀法制备了纳米级四氧化三铁,考察pH值、温度对铅吸附的影响及吸附动力学和吸附等温模型。结果表明,准二级动力学方程能更好地描述纳米级四氧化三铁对铅的吸附动力学过程,反应分为快速吸附阶段、慢速吸附阶段和吸附平衡阶段。pH对四氧化三铁吸附铅的过程有着明显的影响,pH过低会导致四氧化三铁对铅的吸附量降低。温度会影响四氧化三铁对铅的吸附量,温度越高,吸附量越小。Langmuir方程更适合描述四氧化三铁对铅的吸附行为,该过程为化学吸附。     

四氧化三铁/聚丙烯酸甲酯微球吸附金属离子

以二乙烯基苯为交联剂,采用悬浮聚合法制备Fe3O4/ 聚丙烯酸甲酯磁性微球,并经胺基化改性后制得一种新型吸附剂(FADA).采用扫描电镜(SEM),X射线衍射(XRD),红外光谱(IR),热重分析(TGA)等手段分析了它的结构特点,并考察了它对金属离子的吸附性能.实验结果表明,FADA粒径为35～55μm,FADA 中Fe3O4质量分数约为18%.FADA吸附Hg2 ,Cu2 和Ni2 的等温线符合Langmuir模型,且饱和吸附容量分别为为2.3,和1.1 mmol/g,采用Lagergrent方程计算的吸附速率常数分别为0.023, 0.034和0.036 min-1.FADA的再生和重复使用实验表明,该吸附剂具有良好的再生性能和重复使用性能.     

聚苯胺/四氧化三铁/氧化石墨烯核壳纳米复合材料的制备及其吸附性能的研究

采用氧化法在常温下合成聚苯胺/四氧化三铁/氧化石墨烯核壳纳米复合材料,并作为吸附剂吸附Cu2+离子。用XRD和FT-IR进行表征。研究了不同吸附时间、p H和循环使用次数等对复合物吸附容量的影响,在25℃、溶液p H为4.8时最大吸附能力为43.2 mg/g。该复合材料对Cu2+离子吸附过程符合准二级动力学模型,表明吸附过程涉及吸附物与污染物之间的物理和化学相互作用。     

生物炭负载锰掺杂纳米四氧化三铁吸附除锑研究

为提升晶态铁系金属氧化物的吸附容量、提高对印染废水中高溶解度和稳定性的Sb(OH)₆^-去除效果,制备生物炭负载锰掺杂纳米四氧化三铁,探究其吸附效果与联用生物炭负载提升吸附容量的机理。吸附实验表明,在初始pH为7.0±0.5、温度25℃、初始锑浓度200μg/L条件下,吸附剂除锑的最优条件为锰铁比0.3、负载比0.2、投加量0.3 g/L,此时模拟废水中锑含量可降至38μg/L,在更低投加量、更温和pH、室温条件下有更高的吸附容量。且吸附剂的循环使用性能较好,经三个吸附-脱附循环后吸附量仍达86%。吸附容量机理研究发现,生物炭负载提升吸附容量的机理为缓解团聚、提高吸附剂表面带正电强度、增强其对Sb(OH)₆^-的离子交换吸附作用。     

抗坏血酸提高纳米四氧化三铁稳定性研究

利用抗坏血酸对磁性纳米四氧化三铁进行修饰,制备出能对酸性体系稳定的磁性材料,通过傅立叶变换红外光谱和热重分析对制备的Fe_3O_4-AA(抗坏血酸)复合材料进行了表征,实验结果表明抗坏血酸能对纳米Fe_3O_4颗粒有较好的结合能力,从而提高了纳米Fe_3O_4的稳定性,这对于制备耐酸性纳米四氧化三铁具有重要意义。     

碳／四氧化三铁纳米复合材料合成研究

为提高四氧化三铁纳米粒子的催化活性和稳定性,采用均匀沉淀方法制备了活性炭/四氧化三铁(AC/ Fe3O4)粒子和碳纳米管/四氧化三铁(CNTs/Fe3O4)粒子两种复合材料,利用扫描电子显微镜(SEM)、X射线衍射分析(XRD)以及热重分析(TGA)对复合粒子进行了表征,并测定了它们的电化学性能.研究结果表明:采用该方法制备的四氧化三铁粒子纯度高、大小均匀,粒径在40～100 nm;CNTs/Fe3O4中的四氧化三铁粒子粒径较AC/Fe3O4中的更小;经过超声波作用后CNTs/Fe3O4的稳定性较好,而AC/Fe3O4的稳定性很差;两种复合材料均能改善镧镁镍合金的放电比容量和稳定性.     

水热体系中四氧化三铁与氧化石墨烯复合纳米颗粒的合成

在200℃自气压水热条件下制备了四氧化三铁与氧化石墨烯复合纳米颗粒。使用透射电子显微镜(TEM)、X射线粉末衍射仪(XRD)、扫描电子显微镜(SEM)等一系列仪器进行表征,结果表明四氧化三铁与氧化石墨烯复合纳米颗粒由粒径大约20 nm的四氧化三铁纳米颗粒与氧化石墨烯复合而成,数据分析表明氧化石墨烯对于四氧化三铁纳米颗粒的形成和进一步演化起到了一定的作用。     

合成碳羟基磷灰石对水中苯酚的吸附

利用废弃蛋壳为原料、尿素为添加剂,合成了碳羟基磷灰石(CHAP),用于吸附水中苯酚. 利用红外光谱、扫描电镜、X射线能谱测试技术对CHAP样品表面化学进行了表征,同时考察了环境pH值、吸附时间、苯酚初始浓度及温度对苯酚吸附的影响. 结果表明,在酸性(pH=3~5)和碱性(pH=9~10)条件下,CHAP对苯酚的吸附效果较好,吸附过程符合Langmuir和Freundlich等温式,同时也符合准二级动力学模型.     

砷对离子交换法吸附硫酸锌溶液中氯离子的影响

对某企业提供的含Cl－1．55 g／L、含砷2．24 g／L、含Zn2＋145 g／L的硫酸锌溶液,采用大孔阴离子交换树脂吸附Cl－。结果表明,达到稳定平衡后,离子交换树脂对Cl－的吸附容量为21．2 mg／g,与无砷硫酸锌溶液比较,对Cl－的吸附容量下降19％。     

水溶液条件下膨润土对葡萄糖分子的吸附作用(英文)

采用X射线衍射谱和红外吸收光谱分析膨润土对于葡萄糖分子的吸附特性,研究了膨润土的吸附等温线。同时,探究了膨润土与葡萄糖溶液的接触时间及溶液的初始pH值等对于膨润土吸附作用的影响。以Freundlich模型为基础对等温线数据进行拟合和分析。结果表明:在水溶液条件下,膨润土中的主要成分为蒙脱石,在其层间能够吸附葡萄糖分子;随着初始溶液pH值的增加,膨润土对于葡萄糖分子的吸附能力逐渐增强,吸附效率逐渐提高。     

磷酸铁对砷吸附性能的研究

采用实验室自制磷酸铁,从溶液的p H值、砷初始浓度、温度、搅拌速度等方面探讨磷酸铁对砷的吸附作用。得到磷酸铁吸附砷的最佳工艺条件为：砷初始浓度为0.000 1 mol/L、p H=7、搅拌速度为600 r/min、反应体系温度为80℃和反应时间为1 h,该条件下磷酸铁对砷的吸附效率达到99.6%。为解决饮用水或土壤中砷污染的问题提供一定的参考意义。     

Adsorption of Zn on Synthetic Hydroxyapatite from Aqueous Solution

The aim of this paper was to discuss the changes in the double electrical layer at the hydroxyapatite /electrolyte solution interface during zinc ions adsorption. The second aim was establishing the relations between time and adsorption on this material. Hydroxyapatite of a determined specific surface area was prepared by the wet method, characterized by XRD methods, scanning and atomic microscopes. Moreover, the specific surface area was characterized and the grain sizes were determined. Studies of adsorption were carried out using ⁶⁵Zn isotopes and ionic solutions containing this ion depending on concentration and pH of the solution. Zn adsorption isotherms on hydroxyapatite were determined. The effect of the presence of zinc ions on grain sizes surface charge density and zeta potential was discussed.     

Experimental and Numerical Modeling Studies of Arsenic Removal with Wood Ash from Aqueous Streams

Most of the arsenic removal processes are not cost‐effective and/or not efficient in removing As (III). In this research, it was found that Maple wood ash has the potential to adsorb both As (III) and As (V) from contaminated aqueous streams at low concentration levels without any chemical treatment. Static tests showed up to 80% arsenic removal and in various dynamic column tests the arsenic concentration was reduced from 500 ppb to lower than 5ppb. Finally, the ash column was modeled using the surface excess theory. The identified model significantly facilitates practical design of arsenic adsorption system.     

高炉渣对碱性品蓝吸附性能的研究

本试验研究了高炉渣对碱性品蓝的吸附性能,借助电镜扫描(SEM)技术对吸附剂进行了表征,探讨了碱性品蓝的初始浓度、吸附时间、吸附剂投加量、吸附温度、离子强度和废水pH等因素对碱性品蓝去除率的影响,并从动力学和等温吸附模型探讨了吸附作用机理.实验结果表明:当吸附温度为室温(25℃)、吸附剂加入量为0.4g、吸附时间为120 min、废水pH为8、初始碱性品蓝浓度为100 mg/L、离子强度为0 mol/L时,碱性品蓝去除率达78.31％;高炉渣对碱性品蓝的吸附符合伪二级动力学方程和Freundlich等温吸附模型,并且吸附是容易发生的.     

Adsorption of Lignosulfonate Compound from Aqueous Solution onto Chitosan-Silica Beads

The main objective of this study is to investigate the possibility of crosslinked chitosan-tetraethoxy orthosilane (TEOS) (chitosan-silica) beads to be used as an adsorbent material to adsorb the lignosulfonate compound in solution. Different parameters affecting the adsorption capacity such as contact time, adsorbent dosage, initial concentration, pH, ionic strength, and temperature have been investigated. Adsorption isotherms of lignosulfonates onto chitosan-silica beads were also studied. Batch adsorption experiments were carried out and the optimum lignosulfonate adsorption onto chitosan-silica beads occurred at contact time of 30 minutes, the adsorbent dosage of 40 g/L, initial concentration of 50 mg/L, pH 5, and a temperature of 45°C. Adsorption isotherms studied through the use of graphical methods revealed that the adsorption of lignosulfonates onto chitosan-silica beads follows the Langmuir model, with the maximum adsorption capacity being 238.3 mg/g at pH 7. Adsorption is dependent on the ionic strength. The adsorption of lignosulfonate on chitosan-silica beads was best described with the pseudo-second-order kinetic model with a rate constant of 0.32 g · mg^?1 · min^?1, while intra-particle-diffusion was the main rate-determining step in the lignosulfonate adsorption process. The chitosan-silica beads investigated in this study were thus exhibited as a high potential adsorbent for the removal of lignosulfonate from solution.     

蒲草根对阴离子染料刚果红的吸附及其机理研究

文章探讨了水生植物废弃物蒲草根对阴离子染料刚果红的吸附及其作用机理。考察了蒲草根剂量、接触时间、颗粒粒径大小和环境温度等因素对吸附的影响,并对吸附过程进行热力学和动力学分析。结果表明,蒲草根对刚果红染料的吸附是一个自发和散热的过程,并且该过程符合Langmuir等温线方程（R2〉0．98）,最高去除率达98．4％。     

Adsorption of Pyridine from Aqueous Solution by Surface Treated Carbon Nanotubes

Abstract

The surface treatment of multi‐walled carbon nanotubes (MWCNTs) with acid, heat, ultrasonic, and polyvinyl alcohol has been examined. The original CNTs and four treated CNTs were first used as adsorbents to remove pyridine from water and the adsorption isotherms of pyridine on CNTs were studied. At the same time, the effect of pH, temperature, and the adsorption kinetics on the adsorption of pyridine were also evaluated. The experiments show that the adsorption of pyridine on different CNTs is mainly a physical process and the data fit the Freundlich adsorption isotherm well. The short time needed to reach equilibrium as well as the high adsorption capacity of pyridine suggests that CNTs possess highly potential applications for pyridine removal from water.