Preparation of new base-aluminum-chloride-loaded fiber as adsorbent for fast removal of arsenic(Ⅴ) from water

A new base-aluminum-chloride-loaded fiber[PET-AA-NN-Al₂（OH）_nCl_6-n]was prepared with polyethylene glycol terephthalate （PET） as adsorbent for fast removal of arsenic（Ⅴ） from water.This new fibrous adsorbent was characterized by using SEM and C NMR spectroscopy.Adsorption kinetic curve indicated that this new fibrous adsorbent could fast remove arsenic（Ⅴ） from water, and adsorption isotherm also indicated that PET-AA-NN-A1₂（OH）_nC1_6-n had high equilibrium adsorption capacity for arsenic（Ⅴ）.     

Preparation of novel chelating sponge as an adsorbent for the removal of Cu~（2＋） from water

The novel chelating sponge modifed with hydroxamic acid groups was prepared by a grafting polymerization followed by a nucleophilic substitution reaction.Elementary analysis,SEM,FT-IR spectroscopy and XPS were used to characterize the spongy adsorbent（PVA-MA-HH）.Adsorption isotherm study indicated that PVA-MA-HH had high equilibrium adsorption capacity for Cu2＋.     

Preparation and application of a novel orotic acid chelating resin for removal of Cu(Ⅱ) in aqueous solutions

A novel chelating resin OABA,capable of removing Cu(Ⅱ) from aqueous solution,was synthesized via the reaction of macroporous chloromethylated PS-DVB copolymer beads with orotic acid.The elemental analysis(EA),Fourier transform infrared spectroscopy(FT-IR),and scanning electron microscopy microscope-energy dispersive X-ray spectroscopy(SEM-EDS) were used in the characterization of the synthesized chelating resin.Multiple,static batch adsorption experiments were conducted at different initial concentrations and temperatures.OABA showed good adsorption capacity for Cu(Ⅱ) and the equilibrium data could be well matched with the Freundlich isotherm model.Coexisting sodium chloride and calcium chloride in solutions favored the Cu(Ⅱ) adsorption.Moreover,the desorption process of Cu(Ⅱ) was tested and over 90%regeneration efficiency for the spent OABA was achieved at ammonia concentrations ranging from 1.0%to 2.0%.The results suggested that OABA would be a potential alternative adsorbent for Cu(Ⅱ),even with other heavy metal ion treatments of wastewater.     

Poly（vinylpyridine） adsorbent for the removal of SIPA from its aqueous solution

Poly(vinylpyridine) WH-225 resin was prepared and characterized.Compared with the commercial hypercrosslinked adsorbent NDA-100 and macroporous adsorbent XAD-4 resins,the newly synthesized poly(vinylpyridine) WH-225 resin exhibited the highest adsorption capacity toward SIPA from aqueous solution.     

Activated carbon cloth as adsorbent and oxidation catalyst for the removal of amitrole from aqueous solution

Removal of amitrole from water was studied by adsorption on an activated carbon cloth and by oxidation with hydrogen peroxide using the same activated carbon cloth as catalyst. Study variables included the solution pH, ionic strength, and temperature in the adsorption process and the solution pH and the surface chemistry of the activated carbon cloth in the oxidation process. Results showed that amitrole adsorption on activated carbon cloth was not adequate to remove amitrole from water due to the high solubility and low aromaticity of the herbicide, which reduced its adsorption on the carbon. A higher amitrole removal rate was obtained with the activated carbon/H₂O₂ system. The best results were obtained on basic activated carbon surfaces at pH 7–10, when hydroxyl radical formation is favored, achieving the removal of 35–45% of the AMT, compared with 20–25% under the best adsorption conditions. Importantly, oxygen fixed on the carbon surface during AMT oxidation must be removed by heat treatment in order to regenerate the surface basicity of the carbon before its reutilization in another oxidation cycle.     

Preparation of magnetite and its decomposition of water

The optimum conditions were studied for the formation of magnetite by the air oxidation of Fe(OH)2 suspensions. The cation-deficient magnetite (Fe3-δO4, δ>0) was obtained by the air (200mL/min) oxidation of Fe(OH)2 suspensions for 8- 25 h at 343 -358 K and NaOH/FeSO4=2.0 (mole ratio). The oxygen-deficient magnetite (Fe3+δO4, δ>0) was prepared through CO gas reduction of the cation-deficient magnetite at 563 K and its stableness at various temperatures and atomspheres was surveyed. The activity of decomposing water into hydrogen gas with oxygen-deficient magnetite at 563 K was studied and its relations to the oxygen-deficient degree and reaction temperature were investigated, respectively. The results show that the longer the time for magnetite being reduced by carbon monoxide, the higher the oxygen-deficient degree, and the more active its dedcomposition of water is. After reaction, oxygen (O2-) was taken away from water by oxygen-deficient magnetite, which converted to the cation-deficient magnetit     

Synthesis of new superabsorbent poly(NIPAAm/AA/N-allylisatin)nanohydrogel for effective removal of As(Ⅴ) and Cd(Ⅱ) toxic metal ions

The present studies highlight the effective removal of As（V） and Cd（II） from aqueous solutions by superabsorbent poly （NIPAAm/AA/N-allylisatin） nanohydrogel. Batch removal studies were performed as a function of treatment time, initial metal ion concentration, pH, and adsorbent dose. TEM micrographs confirm the particle size distribution in the range between 5 nm and 10 rim. The simple and metal ions adsorbed nanohydrogels were characterized by FF-IR, TGA, and EDX analysis. Finally, the equilibrium removal efficiency of the nanohydrogel was analyzed according to the Langmuir and Freundlich adsorption isotherm models which showed the removal of As（V） and Cd（II） metal ions fitted to Freundlich and Langmuir isotherms, respectively. Removal efficiency order of the metal ions is As（V） 〉 Cd（II）.     

Ozonated graphene oxides as high efficient sorbents for Sr(Ⅱ) and U(Ⅵ) removal from aqueous solutions

Ozone was used to oxidize graphene oxides(GO) to generate ozonated graphene oxides(OGO) with higher oxygen-containing functional groups. The as-prepared OGO was characterized by Fourier transformed infrared spectroscopy(FTIR), scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS). Based on the results of potentiometric acid-base titrations, the total carboxylic acid concentration on OGO surface was calculated to be 3.92 mmol/g, which was much higher than that on GO surface. The results of adsorption experiments indicated that the adsorption capacities of OGO for Sr(II) and U(VI) removal were improved significantly after ozonization.     

Bengal gram seed husk as an adsorbent for the removal of dyes from aqueous solutions – Column studies

A continuous fixed bed (column) study was carried out by using seed husk of Bengal gram (Cicer arietinum) (SHBG) as a biosorbent for the removal of direct dye, Congo red (CR) from aqueous solutions. The effects of important factors, such as the value of initial pH, the flow rate, the influent concentration of CR, bed depth, particle size of SHBG, foreign ions and regeneration of CR were studied. The effect of similar type of direct dyes like direct turquoise blue 86 (DTB) and direct black 38 (DB) on the adsorption of CR in column containing SHBG is also studied by keeping other parameters constant. The studies confirmed that the breakthrough curves were dependent on flow rate, initial dye concentration, size of SHBG, initial pH of solution of CR and bed depth. The bed depth service time analysis (BDST) model was applied at different bed depths to predict the breakthrough curves. The model is found suitable for describing the biosorption process of the dynamic behaviour of the SHBG column and the data were in good agreement with BDST model. When the flow rate was 0.67 mL/min and the influent concentration of CR was mg L⁻¹, the column capacity was 6.572 mg g⁻¹. The removal capacity of SHBG was more in case of CR (6.572 mg g⁻¹) compared to other similar direct dyes of DTB (1.984 mg g⁻¹) and DB (1.612 mg g⁻¹). The removal of CR was enhanced in the presence of foreign ion potassium (8.308 mg g⁻¹) and decreased in the presence of calcium (5.58 mg g⁻¹). 120 ml of acetone is required for the completion of regeneration of the column and the total amount of CR recovered in this case. All the results suggested SHBG as a potential adsorbent for removal of CR from aqueous solution so that the rate of bio-sorption process is rapid.     

A heteropore covalent organic framework for adsorptive removal of Cd(Ⅱ) from aqueous solutions with high efficiency

A heteropore covalent organic framework(COF) integrating tetraphenylethene skeleton and catechol segment is designed and synthesized.It exhibits extremely high stability in water under different pH conditions,which makes it an excellent material for adsorptive removal of Cd(Ⅱ) from aqueous solutions with very fast adsorption kinetics,high uptake capacity,and good recyclability.     

Preparation and X-ray Crystal Structure of Di-chlorobis (p-t-butylphenylbutyl Sulfide)Palladium(Ⅱ)

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In situ Preparation of Tri-Fe(Ⅲ) and Bi-Cu(Ⅱ) Clusters from Benzoyl Peroxide Reacting with Metal Powders

Three crystal architectures, including one organic compound of benzoyl peroxide(1) and two clusters of tri-iron(Ⅲ) and bi-cupper(Ⅱ) with benzoic ligands(2 and 3), were self-assembled by an in situ redox way of benzoyl peroxide oxidants reacting with Mo, Fe and Cu powders, respectively. X-ray crystallographic results show that both the asymmetry tri-iron(Ⅲ) cluster and the benzoylperoxide crystal architecture(2 and 1) with complicated 3D networks were constructed by intermolecular hydrogen-bonding interactio...     

Preparation of forcespun γ-irradiated chitin from shrimp shell wastes and its evaluation as uranyl ion adsorbent

Journal of Radioanalytical and Nuclear Chemistry - Chitosan (CS) was synthesized by gamma irradiation of chitin extracted from shrimp shell wastes. CS nanofibers (CS-NFs) with a diameter of...     

Preparation of Pt/K_2La_2Ti_3O_(10) and its photo-catalytic activity for hydrogen evolution from methanol water solution

1 Introduction Conventional energy resources, such as coal, petro-leum products, etc., which are fulfilling most of the world’s energy requirement have been depleted to a great extend. The human being is now facing exhaus-tion of fuel resources in a near…     

Preparation and Characterization of Chromium ( Ⅲ )-Containing α-and β-Tungstosilicates( Ⅱ )

Two new compounds of A- type α-and β-K4.5H2.5[SiW9Cr3(OH2)3O37]·xH2O were synthesized. The two kinds of isomers of α-and β-SiW12-xCrx(x=2, 3) were identified by Second-derivative IR spectroscopy and cyclic voltammetry. The numbers of electrons involved in reductions were obtained by controlled potential electrolyses of the isomers.     

Graphene oxide–starch composite as an efficient adsorbent for removing Cu(II): removal performance and adsorption mechanism

Research on Chemical Intermediates - Water pollution caused by heavy metals is a severe environmental issue. In this work, a graphene oxide–starch composite (GO/WS) was facilely prepared via...     

Cetyltrimethylammonium bromide-coated magnetite nanoparticles as highly efficient adsorbent for rapid removal of reactive dyes from the textile companies’ wastewaters

The utilization of modified magnetite nanoparticles (Fe₃O₄ NPs) with a cationic surfactant (cetyltrimethylammonium bromide (CTAB)) as an efficient adsorbent was successfully carried out to remove reactive black 5 (RBBA), reactive red 198 (RRR) and reactive blue 21 (RTB) dyes from aqueous solutions. First, a reactor was designed to be simple, repeatable and efficient in its synthesis of Fe₃O₄ NPs via co-precipitation method. Then, an orthogonal array design (OAD), four factor-four level (4⁴) matrix was applied to assign affecting factors on removing of the dyes from aqueous solutions. The obtained results from ANOVA showed that the amount of CTAB and NaCl% significantly affect the adsorption of RBBA, RRR and RTB dyes. The sorption kinetics of the dyes were best described by a second-order kinetic model, suggesting chemisorptions mechanism. Also, dye adsorption equilibrium state data were fitted well to the Langmuir isotherm rather than Freundlich isotherm. Also, the maximum monolayer capacity, q_max, obtained from the Langmuir was 312.5, 163.9 and 556.2 mg g^-1 for RBBA, RRR and RTB, respectively. The obtained results in the present study indicated that the CTAB-coated Fe₃O₄ NPs can be an efficient adsorbent material for removal of reactive dyes form aqueous solutions.     

Synthesis of carboxymethyl β-cyclodextrin bonded Fe3O4@SiO2–NH2 core-shell magnetic nanocomposite adsorbent for effective removal of Pb(II) from wastewater

Journal of Sol-Gel Science and Technology - In this work, a novel functionalized magnetic Fe3O4@SiO2 core-shell nanoparticles grafted with carboxymethyl β-cyclodextrin (CM-β-CD) is...     

Preparation of γ-Al2O3 sorbents loaded with metal components and removal of thiophene from coking benzene

Series sorbents of Cu, Zn, Ni, Ce and Ag metal components supported on γ-Al₂O₃ carrier for removing thiophene from benzene were prepared by conventional and ultrasound-assisted incipient-wetness impregnation method. The static adsorption experiments were carried out in the thiophene-benzene solution with thiophene concentration of 500?mg/L. The results show that the desulfurization activity of all γ-Al₂O₃ sorbents modified by different metal components obviously increase, among which the sorbent modified by silver nitrate has the best performance. The active components of sorbents from Cu, Zn, Ni, Ce nitrates loaded on γ-Al₂O₃ carrier are their oxides. Besides Ag₂O, the products of silver nitrate thermal decomposition in sorbent prepared still have Ag⁰ and Ag–O–Al species. The assistant ultrasound in the process of sorbent preparation can not only shorten the impregnation time, but also enrich the pore structure of sorbent and improve the size and distribution of the Ag species, which is favorable to the removal of thiophene from benzene. The desulfurization capacity of sorbent changes with the Ag content loaded. The sorbent with 15?% quality content of Ag prepared by ultrasound-assisted impregnation method has the highest desulfurization efficiency. It could reduce the thiophene concentration to 1.7?mg/L from 500?mg/L at room temperature and ambient pressure, with the desulfurization efficiency of more than 99?%, when the ratio of sorbent to solution was 1:4?(g/mL).     

Optimization of polyacrylonitrile-cysteine resin synthesis and its selective removal of Cu(Ⅱ) in aqueous solutions

Polyacrylonitrile beads(PAN) cysteine(CS) was synthesized from polyacrylonitrile beads(PAN) and cysteine(CS).The content of the functional group and the percentage conversion of the functional group of PAN-CS prepared under the optimum condition using response surface methodology(RSM) for the first attempt were 3.22 mmol/g and 35.78%.The structure was characterized by ET-IR and elemental analysis.The adsorption properties of the resin for Cu(Ⅱ) were investigated by batch and column experiments.Batch adsorption results suggested that PAN-CS had higher adsorption capability for Cu(Ⅱ)than other metal ions and maximum saturated adsorption capacity was 184.7 mg/g.The resin and its metal complexes were studied by FT-IR.Furthermore,the resin can be eluted easily using 1 mol/L HC1.PAN-CS can provide a potential application for selective removal of copper from waste solution.