Synthesis and applications of novel attapulgite-supported Co(II)-imprinted polymers for selective solid-phase extraction of cobalt(II) from aqueous solutions

A simple and reliable approach using surface imprinting technique combined with chitosan incorporated sol-gel process was established to synthesise a novel Co(II)-imprinted polymer (Co-IIP) with attapulgite as the support material. Then the prepared polymer was characterised by using fourier tranmission infrared spectra (FT-IR) and scanning electron microscopy (SEM), and the imprinting mechanism of Co-IIP was proposed. Batch experiments studies were performed to evaluate the adsorption kinetics, selective recognition, adsorption isotherm, desorption and regeneration characters of Co-IIP. Results showed that Co-IIP offered fast kinetics for the adsorption and desortion Co2+ under the optimum conditions. The adsorption and selective recognition Co2+ were both followed the order Co-IIP>attapulgite>NIP. Moreover, Langmuir adsorption isotherm fitted well for the experimental equilibrium data of Co-IIP, and the maximum adsorption capacity of Co-IIP was 31.5 mg g(-1). Furthermore, Co-IIP could be reused four times with only about 13.42 similar to 16.17% regeneration loss, and the enrichment factor was more than 10.0. The developed method was also successfully applied to the determination of trace Co2+ in river sediments with satisfactory results. The relative standard deviation of the method (RSD) and the detection limit (3 sigma) were 1.35% and 0.0263, respectively.