Design and application of thiourea modified D301 resin for the effective removal of toxic heavy metal ions

High adsorption capacity, short adsorption time, and easy regeneration are very important and urgently needed for qualified adsorbents used in removing toxic heavy metals from wastewater. Based on this, a thiourea modified D301 resin (TD301) was designed and prepared via simple grafting polymerization and modification procedure. The TD301 was characterized by the scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The adsorption performances of TD301 towards low concentration of toxic heavy metal ions from aqueous solution were investigated. By virtue of the abundant amine and CS groups, TD301 possesses strong adsorption ability for Hg(II), Pb(II) and Cd(II). The pH and temperature have a great influence on the adsorption capacity. The adsorption capacities of TD301 towards Hg(II), Pb(II) and Cd(II) could reach 454.1, 436.6 and 254.1 mg g−1 at 293 K and pH of 6, respectively. The adsorption process could be well described by the Lagergren-first-order model and was a Langmuir monolayer chemical adsorption. The adsorption thermodynamic experiment indicated that adsorption of TD301 towards Hg(II), Pb(II) and Cd(II) was an endothermic and spontaneous process drived by entropy. In addition, TD301 could be reused almost without any loss in the adsorption capacity.