Factors Determining the Sorption Capacity and Selectivity of Metal-Substituted Carbon Sorbents for Ligand Sorption from the Gas Phase

We have established that it is feasible to significantly increase the capacity and selectivity of carbon sorbents by modifying them with metal ions during sorption from gas/air mixtures of sulfur dioxides and nitrogen, hydrogen sulfide, carbon disulfide, diethylamine, acetic acid, etc. We have determined the role of surface complexation and other factors affecting sorption; we have determined the routes and principles for creating and using new high-capacity and selective sorbents for these materials based on various carbonaceous materials (activated carbons, carbonaceous cloths, semicokes).     

Sorption of Precious Metals with Carbon Sorbents

Sorption of gold and silver cyanide complexes with carbon sorbents based on composite polymeric materials and its thermodynamic characteristics were studied.     

CO2 Sorbents Based on Spherical Carbon and Photoactive Metal Oxides: Insight into Adsorption Capacity,Selectivity and Regenerability

This work aimed to obtain hybrid composites based on photoactive metal oxide and carbon having adsorption properties. The materials, composed of titanium dioxide or zinc oxide and spherical carbon, were obtained from resorcinol-formaldehyde resin, treated in a solvothermal reactor heated with microwaves and then subjected to carbonization, were received. The functional groups of pure carbon spheres (unsaturated stretching C=C, stretching C−OH and C−H bending vibrations), CS/ZnO and CS/TiO₂ samples were determined by FT-IR analysis. The characteristic bands for ZnO and TiO₂ were observed below 1000 cm⁻¹. The thermal oxidative properties are similar for TiO₂- and ZnO-modified carbon spheres. We have observed that the increased carbon sphere content in nanocomposites results in starting the decomposition process at a lower temperature, therefore, nanocomposites have a broader combustion temperature range. The effect of the oxides’ addition to carbon spheres on their adsorption properties was evaluated in detail by examining CO₂ adsorption from the gas phase. The selectivity of CO₂ over N₂ at a temperature of 25 °C and pressure of 1 bar (a novelty in testing CS-based sorbents) calculated for 3.00 CS/TiO₂ and 4.00 CS/ZnO was 15.09 and 16.95, respectively. These nanocomposites exhibit excellent cyclic stability checked over 10 consecutive adsorption–desorption cycles.     

Synthesis and Sorption Properties of Filled Fibrous Sorbents with Immobilized Hetarylformazan Groups

New sorbents were prepared by immobilization of structurally different sulfur-containing hetarylformazans on nonwoven polyacrylonitrile fiber filled with AV-17 anion exchanger. Sorption of some heavy metals on these materials was studied as influenced by various factors. Sorbents for selective recovery of copper(II) in the presence of nickel(II), zinc(II), and cadmium(II) cations were found.     

Comparison of the Sorption Capacity of Carbon Sorbents for Cleanup of Oil and Oil Products from Water Areas

Russian Journal of General Chemistry - The object of the research was to test the sorption capacity of carbon sorbents for cleanup of oil products from water. The goal of the work was to test...     

Thiocarbamoylation of Chlorosulfonated Polystyrene for Preparing Sorbents for Noble Metal Ions

A new sorbent for noble metal ions, ensuring selective recovery of Au(III) ions from aqueous solutions containing interfering 3d metal ions, was suggested. The new functional derivative, poly(thiocarbamoylsulfostyre ne), was prepared by treatment of poly(chlorosulfostyrene) with thiourea. At the total degree of functionalization with sulfo and thiourea groups of up to 1.0, the degree of thiocarbamoylation can be controlled in the range from 10 to 75%. The composition and structure of the polymer-analogous transformation products were characterized by elemental analysis, Fourier IR spectroscopy, and thermal gravimetric analysis with IR identification of the decomposition products. Evaluation of the sorption activity of poly(thiocarbamoylsulfostyrene) has shown that the sorbent takes up Au(III) ions virtually quantitatively with high selectivity from an aqueous solution containing Co(II), Fe(III), Pd(II), and Ni(II) ions.     

High-Performance Chelation Chromatography of Metal Ions on Sorbents with Grafted Iminodiacetic Acid

The chromatographic behavior of some alkaline-earth, transition, heavy, and rare-earth metals on a number of complexing sorbents containing surface iminodiacetic acid (IDA) functional groups is studied. The conditions under which metal retention is determined by complexation on the sorbent surface were established, and the main principles of a new variant of the liquid chromatography, i.e., high-performance chelation ion chromatography (HPCIC), are formulated. The efficiency and selectivity of separation of the metal ions are considered depending on the type of the IDA bonding, the sorbent matrix parameters, the eluent composition, and the temeprature of the chromatographic column. Under optimal conditions, the metal retention is shown to linearly correlate with the stability constants of the respective complexes in the double-logarithmic scale. The application of HPCIC to the analysis of multicomponent systems is considered.     

多壁碳纳米管的纯化及其表面含氧基团的表征

用兼具酸性和氧化性的HNO3水溶液可方便地除去残留在原生态多壁碳纳米管(CNT)上的Ni-MgO催化剂组分,同时在其表面产生某些含氧官能团,使原生态多壁碳纳米管的疏水性表面变为亲水性表面.采用Boehm中和滴定法以及X射线衍射(XRD)、热脱附谱(TPD)、傅里叶变换红外(FTIR)光谱和X射线光电子能谱(XPS)等技术对HNO3处理过的多壁碳纳米管的相组成和表面含氧官能团进行测量和表征.结果表明:所生成表面含氧官能团的总量以经7.0mol·L-1硝酸378K处理24h的CNT为最高;3种主要表面含氧官能团的含量高低顺序为,羧基内酯型羧基酚型羟基.     

Sorption of Metal Ions by Chitosan Copolymers with Vinyl Monomers

Russian Journal of Applied Chemistry - Chitosan copolymers with vinyl monomers: 4-N-vinylpyridine, acrylamide, and acrylic acid, were synthesized and these sorption properties were investigated....     

Agar-immobilized Metal Sulfides and Their Sorption Power with Respect to Ag(I) Ions

Russian Journal of General Chemistry -     

Peculiarities of the Sorption of Amino Acids and Their Metabolites by Medicinal Carbon Sorbents

Theoretical and Experimental Chemistry - A comparative study was made of the sorption capacity and sorption kinetics of amino acids (tryptophan, arginine) and their metabolites (indole, creatinine)...     

Recovery of Metal Ions by Chitosan: Sorption Mechanisms and Influence of Metal Speciation

Chitosan is characterized by a high affinity for metal ions due to its high content of amine groups. The sorption mechanism depends on both the protonation of these amine groups and the speciation of metal ions. Metal cations may be adsorbed at pH close to neutrality by chelation mechanism while metal anions can be adsorbed in acidic solutions through ionic interactions with protonated amine groups. Several examples are considered. The first example focuses on Cd sorption, which proceeds by a chelation mechanism on free non‐protonated amine groups in neutral media. In acidic solutions the protonation of amine groups limits the ability of amine groups to complex Cd. The cross‐linking of chitosan with glutaraldehyde also results in a dramatic decrease of sorption properties due to the decrease in the density of complexation sites available for sorption. The sorption of vanadium(V) and molybdenum(VI) illustrates the high capacity of chitosan for the sorption of oxo‐anions. They are very efficiently sorbed in acidic solutions by ionic interactions. The correlation of sorption capacities with the distribution of metal species shows that the sorbent has a greater affinity for highly charged anionic species. The sorption of complex anionic species such as chloro‐complexes of Pd and Pt; and that of copper complexed with organic ligands have also been studied. The optimum conditions for sorption are obtained when anionic complexes predominate in the solution. The chemical modification of chitosan, obtained by grafting of sulfur compounds, allows modifying the sorption mechanism: the ion‐exchange polymer is transformed to a dual ion‐exchange and chelating polymer.

Copper sorption isotherm in presence of sodium citrate (0.004 M ) (? RNH: fraction of protonated amine groups; ACuC: total fraction of anionic copper complexes; Cu‐FAL: total fraction of copper‐free anionic ligands).     

Coordination Compounds of Alkali Metal Ions with Ligands Containing Phosphoryl Groups

Abstract

Ligands containing phosphoryl groups form coordination compounds with different metals. The coordination compounds of such ligands with alkali metal ions are considered. The effective charge of phosphorus atom in phosphoryl group is approximately + 1, and oxygen atom effective charge is approximately -1. Phosphorus and oxygen atoms effective charges depend on the nature of the substituents at phosphorus.     

Synthesis and Sorption Performance of Novel Sorbents for Selective Solid-Phase Extraction of Eu(III) Ions from Aqueous Solutions

Russian Journal of Applied Chemistry - Magnesium-cadmium hydroxyapatite [(Mg-Cd)HAP] and novel multi-wall carbon nanotubes Mg-Cd hydroxyapatite (CNTs/(Mg-Cd)HAP) composites were synthesized by a...     

羧基淀粉接枝聚合物对重金属离子的吸附速率方程

以Ｃｅ＾４＋为引发剂，将丙烯腈接枝到高交联淀粉上，接枝产物再经皂化水解制得水不溶性羧基淀粉接枝聚合物（简称羧基淀粉）。研究了羧基淀粉吸附重金属离子的动力学行为。实验结果表明，羧基淀粉吸附速率快，吸附平衡时间短，吸附量随时间的变化规律遵从Ｑ／Ｑ∞＝ａｔ（１＋ａｔ）方程。     

Solvation Numbers of Divalent Metal Salts and Ions in Some Non-aqueous Solvents

The few data available so far for the solvation numbers of divalent metal salts in non-aqueous solvents at infinite dilution are augmented by values in methanol, acetonitrile, N,N-dimethylformamide, and dimethylsulfoxide for alkaline earth and first row transition metal salts at 298.15 K. These were obtained from the isothermal compressibilities and the molar electrostriction volumes, as appropriate, with good agreement where comparable. Solvation numbers were evaluated for the individual ions, where possible. The intrinsic volume of the triflate anion was evaluated for this purpose.     

聚苯胺及其复合物对重金属离子的高效吸附性能

基于国外最新文献,系统总结了近年来聚苯胺及其复合物的制备方法及其重金属离子吸附性能,重点分析了吸附性能特征,指出聚苯胺及其复合物具有吸附下限浓度低、达到吸附平衡快以及解吸附性能优异等特点.填充有聚苯胺颗粒的吸附柱在动态处理初始浓度为83 ng/L的汞离子溶液时,经一次吸附与解吸循环操作后,汞离子的富集倍数可达120倍.应用于冷原子吸收光谱的待测样品的浓缩与富集,可以将汞的测试下限拓展到0.05 ng/L.聚苯胺及其复合物在痕量重金属离子的高效富集与灵敏探测等方面展示了广阔的应用前景.     

不同商品炭的表面性质对重金属离子的吸附性能的影响

采用多种商品炭如活性炭(CA)、煤粉(PC)、木质2.0生物炭(L2B)、椰壳生物炭(CSB)、稻壳生物炭(RHB)、硬炭毡(HCF)、软炭毡(SCF)、果壳生物炭(SB)等作为代表,通过各项表征手段检测不同商品炭的表面性质。利用扫描电镜(SEM)观察各商品炭的表面形貌,以傅里叶变换红外光谱(FT-IR)和Boehm滴定法分别定性和定量分析不同商品炭表面官能团的种类和数量,通过对商品炭的形貌结构、表面含有官能团和晶体结构的分析,发现商品炭对重金属离子吸附的主要影响因素是酸性表面官能团,而商品炭形貌及孔隙度影响较小。     

两性淀粉螯合剂吸附性能的研究

采用玉米或红薯淀粉，经环氧氯丙烷交联、醚化剂阴、阳离子化，制得两性淀粉。研究了离子化的方式 、条件与产品螯合容量的关，制得了向种络合容量相当高的两性淀粉，并研究了它们的使用条件及反复利用的可能性能，试验表明两性淀粉螯合剂是一种高效的污水处理剂。