The present investigation attempts to recover the cerium(III) ions from aqueous environment using a novel biohydrogel modified by sporopollenin (SP) and xylan (XY). Optimization of various parameters viz., pH (2.0-10.0), contact time (20-160 min), biohydrogel dosage (1.0-5.0 g/L) and initial Ce(III) concentration (50-450 mg/L) was done. Maximum Ce(III) uptake was noted to be 278.2 mg/g in case of SP- biohydrogel and 180.4 mg/g in case of XY- biohydrogel under optimized conditions. The process was found to follow homogeneous chemical mode of adsorption in case of SP- biohydrogel, whereas heterogeneity and chemical mode of adsorption was noted in case of XY- biohydrogel. This was further confirmed by SEM analysis. Intra-particle diffusion and Boyd plot suggested two phase diffusion in case of both the biohydrogels. Thermodynamic studies showed that the process was endothermic and spontaneous in nature. FT-IR analysis showed the involvement of functional groups viz., aldehydes, esters and hydroxyl groups in case of SP- biohydrogel and amides, alkenes and xylan spectrum for XY- biohydrogel during Ce(III) biosorption. The effects of co- ions in binary and ternary system was studied during Ce(III) biosorption. Maximum adsorption efficiency and recovery of Ce(III) from electronic industrial effluent using SP- biohydrogel were noted as 88.4% and 86.8% which were obtained in column mode at a flow rate of 1 ml/min, bed height of 12 cm and 0% dilution. Regeneration studies suggested that SP- biohydrogel could be reused upto 5 cycles and could serve as a cost effective alternative for the recovery of cerium from waste water.
