Removal of iodate (IO3−) from aqueous solution using LDH technology

Adsorption of iodate (IO3−) from concentrated solutions by LDH materials has been investigated in laboratory scale batch experiments. Very high iodate (IO3−) uptake (close to 100%) was observed in almost all experiments. Adsorption data was compared to the Langmuir and Freundlich adsorption isotherm models as well as the pseudo first and second order kinetic models. The data from the 3:1 Mg/Al LDH thermally activated to 500 °C was best described by the Freundlich isotherm and the pseudo second order model, suggesting that adsorption was a heterogeneous or multilayer process. HPLC data was used in an attempt to identify any conversion of iodate (IO3−) to iodide (I−) during the adsorption process, however, the residual concentration of iodide (I−) was close to or below the limit of detection of the particular analytical technique. This suggests that little or no conversion happened under experimental conditions. •Iodate (IO3−) has been successfully adsorbed from synthetic wastewater solutions using LDHs.•These experiments were carried out in laboratory scale batch experiments.•LDHs thermally activated to 500 °C were best described by the Freundlich isotherm.•This suggests that adsorption was a heterogeneous or multilayer process.•HPLC data suggested that no conversion of iodate (IO3−) to iodide (I−) occurred during adsorption.