Adsorption and removal of cadmium （ Ⅱ ） from aqueous solutions by bio-formulation

A novel sorbent, bio-formulation（BF）, was prepared and employed for the adsorption of cadmium（Cd） ion from aqueous system. The process of adsorption follows the pseudo second-order kinetic equation and the adsorption behavior is fitted with a Freundlich isotherm. The removal rate of Cd is slightly dependent on the initial pH value over a wide range of 4-11. The addition of Zn^2＋ and Cu^2＋ ions hardly affects the Cd adsorption, whereas the coexisting Pb^2＋ ion greatly interferes with the adsorption. The adsorption mechanism is supposed as a cation-exchange process between Cd^2＋ and calcium and Mg^2＋ present on the surface of BF, and somewhat as adsorption in a hydrolyzed form. The adsorbed Cd ions are desorbed effectively by a 0.1 mol/L HCl solution.     

锂离子吸附剂(H2TiO3)的合成及吸附性能

选取TiO2为钛源、Li2CO3为锂源,采用高温固相法合成锂吸附剂前躯体Li2TiO3,并探讨锂钛比、焙烧温度、焙烧时间等因素对合成Li2TiO3性质的影响.将Li2TiO3用一定浓度的盐酸酸洗脱锂后制得偏钛酸型锂吸附剂H2TiO3,酸洗过程中锂的抽出率达到98.86％,而离子筛中的钛溶损却很小.采用XRD和SEM等分析手段对TiO2、Li2TiO3和H2TiO3及其吸附锂后的样品进行表征.最后应用伪一级和伪二级动力学方程对H2TiO3的吸附性能进行研究,并对吸附过程进行拟合从而计算相应的速率常数.结果表明:H2TiO3对锂离子具有较大的吸附能力,吸附过程符合伪二级动力学方程,表明吸附过程主要为化学吸附:在LiCl溶液中的吸附平衡数据符合Langmuir 等温吸附方程,表明吸附过程为单层吸附.     

Degradation of crystal violet using nanometer TiO2 under the synergistic action of H2O2 and ultrasonic wave

TiO2 nanoparticles with different phases are prepared by hydrolysis of titanium tetrabutoxide in the presence of HCl. The composition and microstructure of the resulting samples are studied by XRD and TEM. These results show that the range of particle size of TiO2 is from 20 to 30 nm. The mechanism of TiO2 photocatalysis reaction has been discuss edextensively. Photocatalyfic activities of nanometer TiO2 are also evaluated by degradation of the crystal violet solution. Experimental results indicate that the synergistic action of H2O2 and ultrasonic wave greatly enhances photo-catalytic reaction of TiO2.     

Adsorption behavior of Pd(Ⅱ) from aqueous solutions by D201 resin

The adsorption and desorption behaviors of Pd(Ⅱ) on D201 resin were investigated. The effects of parameters including HCl concentrations, initial metal ion concentrations, contact time, and temperature on the adsorption of Pd(Ⅱ) were studied by batch method. The HCl concentration for studying the effects was set from 0.01 to 2 mol·L-1 and the optimal adsorption condition is in 0.01 mol·L-1 HCl solution. The adsorption isotherm of Pd(Ⅱ) on D201 resin was determined and the equilibrium data fitted the Langmui...     

Adsorption behavior and mechanism of amino methylene phosphonic acid resin for Ag（ Ⅰ ）

1 Introduction Many efforts have been made on using ion exchange resin to separate and concentrate certain metal cations [1?11]. However, less research for using it to adsorb noble metal Ag(Ⅰ), and much less research for commercializa- tion has been don…     

Adsorption properties of Ag（Ⅰ）, Au（Ⅲ）, Pd（Ⅱ） and Pt（Ⅳ） ions on commercial 717 anion-exchange resin

The adsorption properties of the four precious metal ions (Ag(I), Au(II), Pd(III) and Pt(IV)) on the commercial Cl^?-form 717 strongly basic anion-exchange resin were studied in detail. The effects of the contact time, solution acidity, and concentrations of Cl^? and Pb²⁺ ions on the adsorption properties were studied by the batch method. Then, the column method was conducted under the optimized adsorption conditions (pH=3.0). The effects of the sample loading flow rate and the length-to-diameter ratios of the columns were investigated. The precious metal ions adsorbed could not be eluted completely after the saturated adsorption because the precious metal ions were found to be reduced to their metallic states during the adsorption process. So, it is recommended that the commercial Cl^?-form 717 strongly basic anion-exchange resin should be decomposed directly to recovery the precious metals after the saturated adsorption.     

Photocatalytic reaction kinetics model based on electrical double layer theory Ⅱ.Infrared spectroscopic characterization of methyl orange adsorption on TiO2 surface

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Adsorption of [Au(CN)2]− ions from aqueous solutions on an activated carbon surface

Sorbent capacity and kinetics of the adsorption process on synthetic carbons (FAS grade) and commercial coconut shell activated carbons were studied in the system activated carbon-aqueous solution of sodium dicyanoaurate(I). The effect of progressive activation of carbons on the adsorption value was analyzed. The method of moments was used to calculate the internal diffusion coefficients and show their relation to the structure of activated carbons.     

合成纳米TiO2／不饱和聚酯树脂（TiO2／UPR）的研究

将纳米TiO2粉加入到不饱和聚酯中进行同时增韧增强改性时，发现用简支梁冲击强度表征纳米TiO2／UPR的韧性时，树脂有明显的脆韧转变现象，脆-韧转变点为TiO2含量是6％。纳米TiO2／UPR弯曲强度和冲击强度较UPR分别提高了55％和46％。利用扫描电子显微镜观测纳米TiO2/UPR的冲击断口形貌时，发现在脆-韧转变点左右的纳米TiO2／UPR的微观形态发生了从脆性断裂到韧性断裂的形貌特征。     

泡沫镍负载TiO2和TiO2/3Al2O3·2SiO2薄膜的光催化性能

以泡沫镍为载体,3Al2O3·2SiO2作为过渡中间层,用溶胶-凝胶法在泡沫镍上负载锐钛矿相的TiO2薄膜,制成泡沫金属基的TiO2和TiO2/3Al2O2·2SiO2光催化材料,利用TG-DSC、XRD和FE-SEM等测试手段对其进行表征,用乙醛气体的光催化降解测试其光催化活性.研究表明泡沫镍负载的TiO2和TiO2/3Al2O3·2SiO2薄膜均具有良好的光催化活性,其中,由于负载的3Al2O3·2SiO2过渡中间层增大了载体的比表面积,使负载光催化剂的活性位大大增加,因此,TiO2/3Al2O3·2SiO2薄膜的光催化活性较单一的TiO2薄膜有非常显著的提高.     

MgCl_2改性柑橘皮对水溶液中重金属离子的吸附性能

以柑橘皮(OP)为原料,通过MgCl2进行改性制备新型柑橘皮生物吸附剂MgOP。考察溶液pH值、温度、固液比、吸附时间和金属离子浓度对MgOP从单组分溶液中吸附Cu2+、Cd2+、Pb2+、Zn2+和Ni2+的吸附性能的影响。结果表明,pH值和固液比对吸附率的影响较明显;温度对吸附率的影响较小;所有吸附过程可在20 min内达到吸附平衡,对5种金属离子的吸附动力学均符合准二级动力学方程;与原始柑橘皮相比,MgOP对5种金属离子的最大吸附量显著提高;MgOP可重复使用10次以上;共存金属离子对吸附率影响很小。     

采用锰矿从水溶液中吸附铅和镉离子(英文)

采用低成本的本地可得的天然锰矿作为吸附剂,研究吸附工艺从水溶液中脱除铅离子和镉离子。利用伪一级、伪二级动力学和颗粒内扩散模型检验动力学吸附数据,计算和比较这些动力学模型的吸附速率常数,发现用伪二级动力学模型能最佳地描述吸附动力学。将 Langmuir 和 Freundlich 等温吸附模型用来拟合不同温度下的平衡数据,发现实验数据与 Langmuir 模型拟合得更好。采用 Langmuir 等温吸附模型计算出锰矿吸附铅离子和镉离子的最大容量分别为 98 和 6.8 mg/g。计算了热力学参数,如吸附吉布斯自由能的变化、焓变与熵变。结果表明,锰矿作为吸附剂对铅和镉的吸附反应是自发的吸热反应。因此,锰矿作为一种天然的矿物吸附剂,可以替代现有的吸附剂来脱除水溶液中的铅离子和镉离子。     

H2在Mo(001)表面吸附的第一原理研究

采用第一原理的密度泛函理论(DFT)计算了H2分子在Mo(001)表面的吸附,得到了吸附构型的各种参数,并且计算了H2分子在Mo(001)表面3个位置(顶位,桥位,穴位)吸附后的能量,结果表明在穴位吸附能最高。分析了H原子与Mo原子最临近距离dH-Mo与H2分子的键长在吸附前后的变化;通过对H2分子及在Mo(001)表面吸附的态密度图的分析,最后得出吸附主要原因是由于H2分子的1s轨道与Mo的4d轨道发生相互作用。     

Photoelectric properties of thin Eu3+-doped TiO2 films sensitized by cis-RuL2(SCN)2·2H2O

Thin nanocrystalline TiO2 films doped by europium ions (Eu3+) were obtained by the sol-gel method. The photoelectric properties of Eu3+-doped TiO2 film electrode sensitized by cis-RuL2(SCN)2·2H2O(L=cis-2,2'-bipyridine-4,4'-dicarboxlic acid) ruthenium complex were studied. The thin filmswere characterized by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. Effect of doping Eu3+ on microscopic structure and photoelectrical properties were discussed. The result shows that doping europium ions makes specific surface area of these films larger, which contributes toimproving the photoelectric properties. It is found that an optimal compositiondoped with 0.2 mol.% Eu3+ exhibits the highest photoelectric properties. I sc is 0.37 mA·cm-2 , which is 0.17mA·cm-2 bigger than that of un-doped films;Voc is 405 mV, which is 50 mV bigger than thatof un-doped films.