Cr(VI)-imprinting thiosemicarbazide-functionalized sodium alginate (IIPTSC@SA) microspheres were fabricated to achieve the good selective adsorption for Cr(VI) removal from aqueous solution containing multiple ions. The selective adsorption and reusability of IIPTSC@SA microsphere were intensively investigated. The results showed that the grafting conditions of thiosemicarbazide were optimized at 0.2 g of TSC at 60 °C for 5 h and the ion-imprinting conditions at 100 mL of 2 wt % glutaraldehyde at 60 °C for 6 h. IIPTSC@SA microspheres exhibited the maximum adsorption capacity of 252.5 mg/g and good selectivity to remove Cr(VI) from multi-ion coexisting water. The adsorption process complied with a monolayer adsorption by virtue of chemical interactions together with endothermic spontaneously. After eight adsorption-desorption, the adsorption capacity and selectivity of IIPTSC@SA microspheres remained relatively stable.
Keywords: Functionalization; ion-imprinting; selective adsorption; sodium alginate; thiosemicarbazide.