HYDROTHERMAL SYNTHESIS OF A HYBRID ADSORBENT Ce:Mn-CARBON FOR FLUORIDE REMOVAL FROM WATER

摘要

Fluorine can be present in drinking water and is considered beneficial human being at levels of around 0.8 to 1.0 mg L~(-1),but it is dangerous if it exceeds 1.5 mg L~(-1),which is the maximum limit recommended by the World Health Organization(WHO).Exposure to high concentrations of fluoride can cause dental and skeletal fluorosis or neurological damage,and in severe cases,increased susceptibility to kidney disease and cancer.Fluoride concentrations of up to 30 mg L~(-1)can be found in groundwater in many parts of the world and are present in at least 25 countries.Due to the above,it is necessary to develop new technologies and highly efficient materials for the fluoride removal from water.In recent years,bimetallic oxides as Ce-Mn;Fe-Ti;Ce-Ti and Al-Mn have had a great interest in the fluoride removal and/or other contaminants.However,these bimetallic oxides have been studied in colloidal or nanoparticles form,which makes their application quite difficult in continuous systems.Therefore,it is desirable to anchor these nanoparticles on a support to allow their application.Activated carbon is a poor adsorbent for fluoride,but this can provide a stable support to achieve a high dispersion of metallic phases that have a high fluoride adsorption capacity.Therefore,the objective of this research is to improve the adsorption capacity of fluorides of granular activated carbon by anchoring Ce-Mn oxyhydroxides on its surface by means of hydrothermal synthesis assisted by a microwave oven.