Sorption of some rare earth elements from aqueous solutions using copolymer/activated carbon composite: Multivariate optimization approach

Abstract

The present study investigated the sorption of Ce3+, Nd3+ and Gd3+ cations from aqueous solutions via the use of a synthesized poly (acrylamide-acrylic acid)/activated carbon ((P-AM-AA)/AC) prepared by ϒ Radiation-Induced Template polymerization technique. The effect of absorbed ϒ radiation dose rate (kGy/hr) and cross linker concentration on the sorption efficacy of the synthesized composite toward the concerned lanthanides was studied. The structure of the synthesized composite was confirmed by different characterization techniques. Batch sorption studies for Ce3+, Nd3+ and Gd3+ onto (P-AM-AA)/AC were investigated as a function of contact time, pH and cations concentration. The response surface methodology (RSM) was employed to optimize and simulate the sorption of the concerned cations from the solution onto the synthesized material. The studied factors include initial cation concentration, solution pH, contact time and temperature. From the desirability analysis it is found that, the optimal sorption efficacy of the cations onto the synthesized sorbent was determined as 50 mg/l, 3.9 pH, 7 min and 333 K for acquiring percentage sorption more than 98% with optimal desirability of 0.99.