Adsorption of Cu²⁺ and Ni²⁺ from Aqueous Solution by Arabinoxylan Hydrogel: Equilibrium, Kinetic, Competitive Adsorption

Abstract

In this work, arabinoxylan-graft-acrylic acid (AX-g-AA) hydrogel was prepared and used as an adsorbent to remove and recover Cu 2þ and Ni 2þ from aqueous solutions. The influences of pH, ligand content on the adsorption capacity of the hydrogel, adsorption equilibrium, and kinetic were studied in detail. The competitive adsorption and recovery of heavy metal ions, regeneration and reusability of the hydrogel were present. Furthermore, the relationship between the physiochemical properties of the adsorbent and its adsorption performance was also studied. The results showed that a more expanded network favored the diffusion and adsorption of metal ions. Cu 2þ and Ni 2þ uptake by this hydrogel was pH and concentration dependent with the maximum loading of 330.1 mg/g for Cu 2þ and 248.7 mg/g for Ni 2þ . The pseudo-second-order kinetics suggested that the ion exchange process was chemisorptioncontrolled. The Langmuir equation could well describe the isotherm data. Cu 2þ and Ni 2þ adsorbed on the hydrogel could be effectively recovered in a diluted HNO 3 solution (0.01 M) in 30 min. AX-g-AA hydrogel also exhibited highly efficient reusability, and thus could be used repeatedly.

Design of renewable poly(amidoamine)/hemicellulose hydrogels for heavy metal adsorption

“…A higher adsorption of Cu 2+ compared with Pb 2+ was in agreement with the behavior of a hemicellulose hydrogel based on arabinoxylan and cross‐linked with acrylic acid . The adsorption capacity of the arabinoxylan hydrogels was generally higher than those of the MBAGD‐ and MBAMP‐based hydrogels and could be controlled by varying the ratio of acrylic acid showing the important contribution of carboxyl functionalities to the hydrogel behavior …”

“…A xylan hydrogel designed to adsorb heavy metals was prepared by copolymerization with acrylic acid and shown to efficiently adsorb Cd 2+ , Pb 2+ , and Zn 2+ from aqueous solution . Similarly, but to a lesser extent, a hydrogel prepared from arabinoxylan and acrylic acid adsorbed Cu 2+ and Ni 2+ . AcGGM functionalized and cross‐linked with glycidyl methacrylate and [2‐(methacryloyloxy)ethyl]trimethylammonium chloride was prepared for the adsorption of Cr 6+ and As 5+ …”

Removal of heavy metal ions from aqueous solution by superabsorbent poly (NIPAAm/DAPB/AA) amphoteric nanohydrogel

“…(2015) [1][2][3][4][5][6][7][8][9][10][11][12][13][14] www.deswater.com doi: 10.1080/19443994.2015.1060171 amine, carboxylic acid, and sulfonic acid groups of hydrophilic polymers, which may be cross-linked by chemical or physical interactions. Such hydrophilic polymers, which can absorb, swell, and retain aqueous solutions up to hundred times to their own weight, are able to expand in volume with respect to changes in external parameters, such as pH, temperature, and ionic strength [11].…”

“…Entire removal study and characterization were performed on nanohydrogel V-03 as it has maximum percentage swelling. Removal study was carried out by taking specified amount (0.025 g) of adsorbent in 50 mL of metal ions solution at various initial concentrations (100-500 ppm), pH values (pH range [2][3][4][5][6][7][8][9][10][11][12][13][14], and adsorption doses (10-50 mg). After equilibrium, concentration of metal ions remaining in the solution was determined with a UV-visible spectrophotometer after 8 h. Maximum adsorption capacity and/or % removal efficiency (RE %) of nanohydrogels were calculated using the following Eqs.…”

“…Recently, adsorption is the most promising process due to its high efficiency, ease of operation, and costeffectiveness [6,7]. In this respect, researchers are interested to work with superabsorbent hydrogels as the selective adsorbent material for the removal of such heavy metal ions from wastewater [8][9][10].…”