Efficient removal of fluoride ions present in industrial effluents using metal-organic frameworks of UiO-66-NH2

In this last decade, numerous works have been published on the use of metal organic frameworks (MOFs) for applications in adsorption field to remove contaminants from aqueous solutions. However, little is known about MOFs as adsorbents for the removal of fluoride ions from real effluents. In this work, a highly porous MOF, UiO-66-NH2, was used for the final treatment of complex discharge waters containing fluoride ions from a surface treatment plant. Batch experiments showed that MOF exhibited high adsorption capacities towards fluoride ions, leading to concentrations under current regulation values. 70-80 % of the fluoride was removed in 60 min using 100 mg of MOF in 50 mL of effluent without changing the industrial initial pH. At the same time, the treatment also completely eliminated traces of aluminium in the discharge water. All the results showed that adsorption onto a non-conventional material such as UiO-66-NH2 can be an interesting tertiary treatment step to remove more pollutant streams from multi-contaminated industrial discharge waters.