Porous Chelating Resin Research Articles

Preparation of 6-Amino-N-hydroxyhexanamide-Modified Porous Chelating Resin for Adsorption of Heavy Metal Ions.

The pollution of water bodies by heavy metal ions has recently become a global concern. In this experiment, a novel chelating resin, D851-6-AHHA, was synthesized by grafting 6-amino-N-hydroxyhexanamide (6-AHHA) onto the (-CH2N-(CH2COOH)2) group of the D851 resin, which contained a hydroxamic acid group, amide group, and some carboxyl groups. This resin was developed for the purpose of removing heavy metal ions, such as Cr(III) and Pb(II), from water. The findings from static adsorption experiments demonstrated the remarkable adsorption effectiveness of D851-6-AHHA resin towards Cr(III) and Pb(II). Specifically, the maximum adsorption capacities for Cr(III) and Pb(II) were determined to be 91.50 mg/g and 611.92 mg/g, respectively. Furthermore, the adsorption kinetics of heavy metal ions by D851-6-AHHA resin followed the quasi-second-order kinetic model, while the adsorption isotherms followed the Langmuir model. These findings suggest that the adsorption process was characterized by monolayer chemisorption. The adsorption mechanism of D851-6-AHHA resin was comprehensively investigated through SEM, XRD, FT-IR, and XPS analyses, revealing a high efficiency of D851-6-AHHA resin in adsorbing Cr(III) and Pb(II). Specifically, the (-C(=O)NHOH) group exhibited a notable affinity for Cr(III) and Pb(II), forming stable multi-elemental ring structures with them. Additionally, dynamic adsorption experiments conducted using fixed-bed setups further validated the effectiveness of D851-6-AHHA resin in removing heavy metal ions from aqueous solutions. In conclusion, the experimental findings underscored the efficacy of D851-6-AHHA resin as a highly efficient adsorbent for remediating water bodies contaminated by heavy metal ions.

Construction of arsenic selective chelating resin with iron precursor for removal of low-concentration arsenic: Breakthrough modeling and field deployment

The presence of exorbitant arsenic contamination in the aquatic environment causes astronomically immense health quandaries affecting millions of people, which may lead to death in the case of prolonged indigestion of arsenic-containing drinking water. Herein, we are reporting porous chelating resin with an iron precursor for the removal of arsenic ions from water. Weak acid cation resin was functionalized under varying experimental conditions to get a suitable resin with high arsenic uptake. The theoretical results revealed that the maximum Langmuir adsorption capacities of 3.27 mg g−1 and 1.13 mg g−1 were achieved for As(V) and As(III), respectively. The kinetics of adsorption followed the pseudo-second-order (PSO) model with a high determination coefficient (R2) of 0.9963 and 0.9895 for As(V) and As(III), respectively. The Adams-Bohart, Thomas, Yoon-Nelson, and Pore diffusion models were used to identify the breakthrough curve in the fixed bed adsorption column. The column performance improved with a larger bed height (55 cm), low concentration of influent (0.25 mg L−1), and low flow rate of influent (80 mL min−1). Under this condition, the breakthrough time and exhaustion time were 314 min and 408 min for As(V) and 124 min and 185 min for As(III), respectively.

Adsorption of lead(II) from aqueous solution by two modified porous chelating resins based on (3-mercaptopropyl) trimethoxysilane

Two novel types of thiol-based chelating resins were fabricated by modifying poly(2-hydroxyethyl methacrylate-co-glycerol dimethacrylate) (P(HEMA-GDMA)) and poly(2-hydroxyethyl methacrylate-co-ethylene glycol dimethacrylate) (P(HEMA-EGDMA)) with (3-mercaptopropyl) trimethoxysilane(MPS), and used to adsorb lead(II) from aqueous solution. The effects of initial lead(II) concentrations, solution pH, coexisting ions on adsorption of lead(II) were investigated. After modifying, the product P(HEMA-GDMA)-SH has excellent adsorption capacity (118.56 mg/g) for lead(II) at initial lead(II) concentration of 200 mg/L. The resins could easily be regenerated and were reused 6 times without significant loss of adsorption capacity. Besides, the presence of coexisting ions did not markedly influence the adsorption capacities of the resins. The results indicate that the functional thiol-based resins are efficient adsorbents for the removal of toxic lead(II) ions in water treatment. Open image in new window

Synthesis and characterization of a new iminodiacetate chelating resin for removal of toxic heavy metal ions from aqueous solution by batch and fixed bed column methods

New porous chelating resin beads CPN-IDA were prepared by the reaction of poly (acrylonitrile-co-N,N'- methylenebisacrylamide) with etheylenediamine and sodium chloroacetate, respectively. The composition and morphology of the chelating resin was characterized by Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA and DrTGA), scanning electron microscopy (SEM),surface area measurements by N2adsorption (SBET) and water regain (w%). Batch adsorption experiments were employed to study the impact of some factors that control the adsorption of metal ions including solution pH, concentration of metal ions, contact time and the temperature of the solution. Batch sorption results showed that the chelating resin had high affinity towards Cu(II), Cd(II) and Pb(II). The saturated adsorption capacity at 25 oC was 2.43, 1.93 and 1.45mmolg−1 resin for Cu(II), Cd(II) and Pb(II), respectively. Among the empirical isotherm models, the equilibrium adsorption results were obviously fitted with Langmuir model. The kinetics was analyzed using pseudo-first-order, pseudo-second-order, and intra-particle diffusion equations. The adsorption kinetic data were well elucidated with pseudo-second-order kinetic model. Thermodynamic parameters were calculated for the uptake of the metal ions under study and it was found to be a spontaneous process. Moreover, the adsorption of metal ions has been studied using column technique. The regeneration of CPN-IDA was experimentally performed by using nitric acid. The chelating resin was used repeatedly for five times with a little decrease in sorption of metal ions.

Fluidization Effect on Removal and Recovery of Palladium (II) From Wastewater by Chelated Ion Exchange Resin

The sorption of Pd (II) on the macro porous chelating resins Lewatit TP 214 has been investigated by batch and fluidized mode. The optimized parameters in batch process were used in fluidization method. It was observed that the time required for complete removal of palladium is minimized nearly to one hour by fluidization and a large amount of solution can be easily treated for removal by fluidization. The best interpretation for the experimental data by batch mode is given by the Langmuir isotherm and the maximum adsorption capacity is found to be 20 mg/g. Acidified thiourea, sulfuric acid, nitric acid, methane sulphonic acid, perchloric acid and hydrochloric acid at various concentrations have been used for elution of Pd (II). It is observed that the mixture of perchloric acid and hydrochloric acid shows maximum recovery up to 98%. It is also observed that acidified thiourea is also suitable for recovery of palladium. Effect of superficial gas velocity, initial concentration of solution and amount of resin on mass transfer coefficient is also studied for the fluidized mode of resin.

Fluoride removal from water by zirconium (IV) doped chitosan bio-composite

Water containing fluoride above 1.5 mg/L leads to health and environmental harms that creates skeletal and dental fluorosis. Adsorption technique prominently removes fluoride from water and its competence is reliant on development of recyclable, environmentally benign adsorbents. Many reported sorbents for defluoridation below stringent level 1.5 mg/L, displayed low to moderate adsorption capacity at varied concentrations and pH. Besides, viable defluoridation techniques are usually unsuccessful in developing countries. In this novel, cheap and efficient porous chelating resin, chitosan doped 20% zirconium (IV) with control morphologies were synthesized for delfuoridation. This bio-composite was at par with commercial alumina to mitigate water fluoride limit up to 1 to 1.5 mg/L. Effect of parameters namely pH, adsorbent dose, contact time and initial fluoride concentration were studied in batch scale. Kinetic data showed a rapid adsorption, indicated practicable operations in packed column. Findings encourage blending with other polymers as an effective option for defluoridation on a large scale. Key words: Fluorosis, chitosan, zirconium, bio-composite, defluoridation, water

Structural development Of TMMA and SSQXN‐8 as porous chelating resins

AbstractSuperfast kinetics of Nd+3, Eu+3, and Gd+3 ions were studied on the surfaces of N,N,N\,N\‐tetramethylmalonamide (TMMA) and silsesquioxane (SSQXN‐8) resins. TMMA and SSQXN‐8 were prepared by suspension polymerization and sol–gel routes, respectively. They were identified using elemental analysis, FTIR, H‐NMR, 13C‐NMR, MIP, and BET surface area. Kinetic investigations were performed in batch conditions and different models were used to fit the data; Boyd and Helfferich models were found the best. The diffusion of the ions through the resins were very fast and found to be in the order of 10−16 m2/S. Effective diffusions of the studied ions were found to be 10−15 order of magnitude and directly proportional to the kinetic energy of the transition state. ΔS* values from −166.044 to −179.297 J mol−1 K−1 were estimated as entropy stability factors of the system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Adsorption Behavior of Metal Ions by Amidoxime Chelating Resins

AbstractIn this work, the acrylonitrile (AN) – divinylbenzene (DVB) –methylacrylate (MA) resin was synthesized via suspension polymerization in the presence of toluene as diluent, and benzoylperoxide (BPO) as initiator. The effect of MA, toluene and alkaline treatment on the exchange capacity of the resin were investigated. The results showed that the anion exchange capacity decreased with an increase in the amount of MA, while alkaline treatment had no significant effect. Also, the cation exchange capacity increased with an increase in the amount of hydrophilic agent and reached a maximum point. The sorption equilibrium was achieved relatively fast within 40 mins, and the resin exhibited affinity towards lead (II), copper (II) and in particular uranium (VI). The adsorption of uranium was directly depended up on the pH value. Furthermore, the macroreticular chelating resin, containing amidoxime group had higher adsorption of uranium (VI) in comparison to other metal ions studied. Finally, the alkaline treatment enhanced the potential for much faster adsorption characteristics and the highly porous chelating resin provided a more favorable pore structure for the rapid rate of diffusion of metal ions.

Adsorption properties of amidoxime resins for separation of metal ions from aqueous systems

In this study, the acrylonitrile (AN)–divinylbenzene (DVB)–methylacrylate (MA) resin was synthesized via suspension polymerization in the presence of toluene as diluent, and benzoylperoxide (BPO) as initiator. The effects of MA as a hydrophilic agent and toluene as a diluent on the anion and cation exchange capacity of the synthesized amidoxime resins were investigated before and after alkaline treatment. The results showed that the anion exchange capacity decreased with an increase in the amount of MA while alkaline treatment had no significant effect. Also, the cation exchange capacity increased with an increase in the amount of hydrophilic agent and reached a maximum point. The sorption equilibrium was achieved relatively fast within 40 min, and the resin exhibited affinity towards lead (II), copper (II) and in particular U(VI), and the order of adsorption affinity were UO 2 2 + > Pb 2+ ≫ Co 2+ > Cu 2+ ≫ Cd 2+. The adsorption of uranium was directly depended up on the pH value. Furthermore, the macroreticular chelating resin, containing amidoxime group had higher adsorption of uranium (VI) than other metal ions studied. Finally, the alkaline treatment enhanced the potential for much faster adsorption and the highly porous chelating resin provided a more favorable pore structure for the rapid rate of diffusion of metal ions.

Removal of heavy metal ions by a chelating resin containing glycine as chelating groups

A porous chelating resin, crosslinked poly(glycidyl methacrylate-glycine) (PGLY), was synthesized through an epoxy group reaction of crosslinked poly(glycidyl methacrylate) with glycine for the removal of Cu(II), Ni(II) and Cd(II) from aqueous solutions. The interaction between a metal ion and chelating groups within PGLY was examined using FT-IR analysis. In single-metal ion solutions, all the adsorptions tended toward equilibrium at 40 min and the equilibrium adsorption capacities of PGLY were 1.22, 1.07 and 0.96 mmol/g for Cu(II), Ni(II) and Cd(II), respectively. Except pH > 4.0, as pH of the solution decreased the adsorption capacity of each metal ion decreased. After 15 cycles of adsorption–desorption operations, the re-adsorption capacities could attain 86–93% of initial values of uptake. When the pH of the mixture solutions were 2 or 2.5, the competitive adsorption tests confirmed this resin had good adsorption selectivity for the recovery of Cu(II) from Cu(II)/Ni(II) or Cu(II)/Cd(II) mixture.

Preparation of porous chelating resin containing linear polymer ligand and the adsorption characteristics for harmful metal ions

A linear copolymer consisting of maleic anhydride and methylvinylether has been immobilized on the interior surface of porous polymer beads. The modified polymer beads thus obtained have formed the starting material for the preparation of metal selective chelating resins by the reaction of the maleic anhydride moiety with appropriate ligands. Cysteamine has been grafted as the pendant ligand and the resulting chelating resin (cysteamine resin) maintains a high porosity and large specific surface area. On the basis of scanning electron microscopy (SEM) and electron dispersion X-ray (EDX) analyses, the linear polymer is distributed from the outer layer to the inner pores of the resin beads. The adsorption characteristics of the cysteamine resin for Cd 2+ and Pb 2+ have been examined with respect to the percentage extraction, adsorption isotherm and reproducibility upon adsorption–regeneration cycles. The chelating resin shows a remarkably high adsorption rate, which has been attributed to the porous nature of the resin and geometrical flexibility of the ligand. Quantitative removal of Cd 2+ and Pb 2+ from aqueous solution has been demonstrated by the column procedure packed with the cysteamine resin.

Porous Chelating Resins from Poly(Acrylonitrile-co-Ethyl Acrylate-co-Divinylbenzene)

Abstract Porous chelating resins have been prepared from acrylonitrile–ethyl acrylate–divinylbenzene copolymers by suspension polymerization with inert diluent followed by reaction with hydroxylamine. The porous structure was characterized by scanning electron microscope and varied greatly with the monomer composition and the amount of diluent. The metal binding properties of the chelating resins containing amidoxime and hydroxamic acid ligands derived from the terpolymers were examined with an atomic absorption spectrometer and an inductively coupled plasma spectrometer. This type of chelating resin has some advantages, e.g., ease of preparation (macroreticular) and particular selectivity for metal ions.

Recovery of uranium from seawater. XII. Preparation and characterization of lightly crosslinked highly porous chelating resins containing amidoxime groups

AbstractA number of lightly cross‐linked poly(acrylonitrile‐co‐divinylbenzene) beads (RN‐5) have been synthesized by suspension polymerization. The use of solvating diluents such as chloroform, dichloroethane, and tetrachloroethane resulted in copolymer beads having highly porous structures. The chelating resins containing amidoxime as a functional group (RNH‐5) have been prepared by the reaction of copolymer beads with 3% hydroxylamine in methanol. A detailed analysis is made of the pore structure of lightly cross‐linked copolymers of acrylonitrile–divinylbenzene and their amidoxime derivatives in the anhydrous state including pore‐size distribution, specific surface area, and pore structure in the aqueous media by means of gel permeation chromatography (GPC). A set of experiments have been performed to ascertain the potential of the resins for the adsorption of uranium from seawater. Because of their modified pore structures, the chelating resins exhibited a marked adsorption rate for uranium in seawater as high as 23 μg of U/cm3 of resin/day without alkaline treatment.

Low-crosslinked Porous Chelating Resins Containing Amidoxime Groups

Low-crosslinked Porous Chelating Resins Containing Amidoxime Groups

放射線グラフト重合法によるウラン吸着用中空糸状アミドオキシム樹脂の合成

中空糸状の多孔性ポリエチレン樹脂を基材とし,放射線グラフト重合法によりシアノ基を導入しグラフト率が79%から127%の4種類のアクリロニトリル樹脂を得た。それぞれをヒドロキシルアミン溶液と反応させてアミドオキシム型キレート樹脂を合成した。元素分析によりアミドキシム化反応における窒素導入量を求めたところ19基材あたり4.3mmo1から8.5mmolであった。導入された窒素の大部分はアミドオキシム基になっていると考えられる。基材において広範囲に分布する細孔半径は,グのラフト反応により分布が狭くなり1000Åあたりに集中した。19樹脂あたりの細孔容積は,2.5cm3/gからおよそ半分に減少したが,1g基材あたりの細孔容積はグラフト率とともに増大し,グラフト率が127%のとき4.5cm3/g-基材となった。比表面積は基材の場合30m2/gであるがグラフト率の増大にともなって減少し,グラフト率が127%のとき15m2/gとなった。アミドキシム化反応における窒素導入量に対し,塩酸および銅はいずれも1.5倍の吸着量を示した。IR測定の結果をも考慮して副反応による酸アミド,ヒドロキサム酸の生成を推定した。導入窒素1原子に対しウラン吸着量は0.64原子の割合であった。