Cross-Linked and Functionalized Acrylic Polymers: Efficient and Reusable Sorbents for Zn(II) Ions in Solution

Abstract

The efficiency of the three types of cross-linked and functionalized with triethylenetetramine (As30 and As32) and acylate diethylenediamine (Cm26) acrylic polymers towards zinc ions from synthetic wastewaters has been investigated under different experimental conditions. The sorption and reusability of metal ions on three types of polymer were studied by the static and dynamic method. The effects of contact time, the initial metal ion concentration, pH, sorbent mass and temperature on the adsorption capacity of the three types of cross-linked and functionalized acrylic polymers were investigated. The thermodynamic parameters associated with the adsorption process were evaluated, and obtained values suggested an exothermic process. The experimental data confirm much better to the Langmuir isotherm than the Freundlich, Temkin, Dubinin–Radushkevich, Sips and Flory–Huggins isotherms. The obtained values for the separation factor, RL were less than 1 one which shows that the adsorption process was favorable. The obtained results indicated that the Cm26 has a higher sorption capacity (1135.77 43 mg g−1) towards zinc ions than As32 (1059.47 43 mg g−1) and As 30 (857.77 43 mg g−1) at 293 K. The adsorption capacity sorbents towards Zn2+ ions after five consecutive sorption/desorption cycles, with 0.1 M Na2CO3 aqueous solution as eluent, decreased with about 5% of the initial sorption capacity and this fact recommended the potential of these functionalized polymers in the removal of Zn(II) ions from residual waters.