Exploiting the performance of hyper-cross-linked polystyrene for removal of multi-component heavy metal ions from wastewaters

In this research, Hyper-cross-linked polystyrene was used for simultaneous removal of nickel and lead ions. The necessary number of experiments and optimum values of each factor were determined using response surface methodology (RSM). The optimum value of temperature, nickel, and lead concentrations, and pH was obtained 60 degrees C, 50.715 mg/L, 80 mg/L, and 7 respectively, for Ni(II) adsorption in which the nickel uptake and selectivity were calculated 146.66 mg/g and 0.511, respectively. The optimum value of temperature, nickel, and lead concentrations, and pH was obtained 65 degrees C, 80 mg/L, 40 mg/L, and 7 for Pb(II) adsorption in which the lead uptake and selectivity were calculated 137.272 mg/g and 3.951, respectively. The different isotherm models have been applied for both single and multi-component systems. It was concluded that both single and multicomponent systems obeyed Freundlich isotherm model, which demonstrated the heterogeneous and multilayer of the adsorbent. Besides, thermodynamic parameters such as Delta H degrees,Delta S degrees, and Delta G degrees expressed the exothermic and spontaneous nature of the adsorption of nickel and lead ions. Finally, the value of Delta H degrees for nickel and lead ions was lower than 40 kJ/mol, which implied the process was physical.