Adsorption isotherms, kinetic, and desorption studies on removal of toxic metal ions from aqueous solutions by polymeric adsorbent

Abstract

Adsorption of Cd(II), Co(II), and Ni(II) on aminopyridine modified poly(styrene-alt-maleic anhydride) crosslinked by 1,2-diaminoethane as an ion exchange resin has been investigated in aqueous solution. Adsorption behavior of these metal ions on the resin was studied by varying the parameters such as pH (2-6), adsorbent dose (0-4.0 g/L), contact time (0-240 min), and metal ions concentration (20-300 mg/L). Adsorption percentage was increased by increasing each of these parameters. The isotherm models such as: Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich were used to describe adsorption equilibrium. The results showed that the best fit was achieved with the Langmuir isotherm equation, yielding maximum adsorption capacities of 81.30, 49.02, and 76.92 mg/g for Cd(II), Co(II), and Ni(II), respectively. The pseudo-first-order, pseudo-second-order, and intra-particle diffusion kinetics equations were used for modeling of adsorption data and it was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. The intra-particle diffusion study revealed that external diffusion might be involved in this case.

Thiourea modified hyper‐crosslinked polystyrene resin for heavy metal ions removal from aqueous solutions

“…[9][10][11][12] In comparison with the traditional adsorbents, such as activated carbons, zeolites, and clays, synthetic polymeric materials have been explored for the removal of heavy metal ions from aqueous solutions. [12][13][14] A set of novel hyper-crosslinked polystyrene resin (HPS) is an efficient polymeric adsorbent because of its unique structure and extraordinary adsorption properties. 15 It can be synthesized from low crosslinked polystyrene by its self Friedel-Crafts reaction, which exhibits a great increase in the specific surface area, pore volume and enhanced adsorption of the aromatic compounds after the reaction.…”

Preparation and characterization of porous cationic poly[styrene‐co‐(N,N′‐dimethylaminoethyl methacrylate)] nanoparticles and their adsorption of heavy metal ions in water

“…Cu 2+ , Zn 2+ , Pb 2+ and Co 2+ were used in the metal ion purification experiments, and the initial amount of metal salts was kept the same to avoid the effect of ionic strength on the adsorption . As shown in Fig.…”

A Suitable Method for Removing of Heavy Metal Ions from Aqueous Solutions Using Proper Copolymer and its Derivations

“…As shown in Figure 2, after CSMA-M and CSMA-MP and CSMA-MB adsorbing heavy metal ions, the band at 1625 cm -1 piked and shifted to lower frequency (at about 1464 cm -1 ), introducing a stronger copolymer-metal bond has wrought between heavy metal ions and carboxyl oxygen in carboxylate salts. Moreover, a predominant peak was appeared at 3458 cm -1 expressing the N-H stretching vibrations of heavy metal salts of amid [40].…”

“…The model of Temkin adsorption isotherm contains a factor that explicitly takes into account adsorbent-adsorb ate interactions [40]. This model assumes the following: (i) the adsorption heat of all molecules in the layer decreases linearly with coverage due to adsorbent-adsorbate interactions, and that (ii) the adsorption is characterized by a uniform distribution of binding energies, up to some maximum binding energy.…”