Efficient capture of radioactive iodine by Ag-attached silica gel and its kinetics

•The removal rate of iodine by self-made Ag-attached silica gel is 98.62 % (wt.%). By selecting the intake air flow and humidity, the adsorption effect of silica gel can be changed.•For the design of Ag-attached silica gel adsorption column, selecting a larger inlet flow can improve the utilization rate of adsorption column.•The height of the packing layer in the adsorption column increases the mass transfer resistance, and changing the height can make the adsorption more complete.•Humidity has no effect on the adsorption of gaseous iodine on Ag-attached silica gel.•Yoon Nelson model can better simulate the dynamic adsorption behavior in the adsorption column of this experiment.