Adsorption of heavy metal ions by iminodiacetic acid functionalized D301 resin: Kinetics, isotherms and thermodynamics

Abstract

High adsorption capacity, fast adsorption rate, easy regeneration and good reusability were very important for qualified adsorbents used in removing toxic heavy metals from wastewater. Based on this, a novel adsorbent was well designed and synthesized by functionalizing D301 resin with iminodiacetic acid (IDA). The physicochemical characteristics of IDA-functionalized D301 (ID301) were characterized by the scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The adsorption performances of ID301 towards toxic heavy metal ions were systematically performed from kinetics to isotherms and thermodynamics by batch technique. The effects of contact time, initial metal concentration, pH, temperature and adsorbent dosage on adsorption performance were investigated. ID301 possesses strong adsorption ability for Cu(II), Pb(II) and Cd(II). pH and temperature has a great influence on the adsorption capacity. The adsorption capacities of ID301 towards Cu(II), Pb(II) and Cd(II) could reach 4.48, 2.99 and 2.26mmol·g−1 at 293K and pH of 5, respectively. Langmuir isotherm and pseudo-second-order equation could satisfactorily describe the experimental data. The adsorption thermodynamic experiment indicated that adsorption of ID301 towards Cu(II), Pb(II) and Cd(II) was an endothermic and spontaneous chemisorption process driven by entropy. In addition, ID301 could be reused without losing adsorption capacity significantly.