Characterization of diatomite and its application for the retention of radiocobalt: role of environmental parameters

► The sorption of Co(II) was strongly dependent on ionic strength at low pH, but independent of ionic strength at high pH. ► A positive effect of HA/FA on Co(II) sorption was found at low pH, whereas a negative effect was observed at high pH. ► Co(II) sorption was a spontaneous and endothermic process. ► The results are quite important for the application of diatomite in Co(II) pollution management.