Synthesis of MgLaFe MMO Composites and Their Adsorption Properties for Co-removal of Fluoride and Arsenic from Water

Abstract

Fluorine and arsenic co-contamination in groundwater is a common phenomenon in Northwest China, leading to serious health problems when consumed as drinking water due to high levels of both contaminants. It is important to note that the region's highly fluoridated and arsenic groundwater is widely distributed. Achieving efficient adsorption and co-removal of these pollutants is particularly challenging due to their co-pollution and strict drinking water standards. The study achieved the preparation of Mg-La-Fe mixed metal oxide composites through a green and stable synthesis pathway. The composites consist of magnesium and lanthanum hydroxides with a strong affinity for fluoride ions and iron, which can form stable compounds for arsenate and arsenite, enabling efficient co-removal of fluoride and arsenic ions. The material can adsorb up to 30.26 mg∙g-1, 36.96 mg∙g-1, and 133.65 mg∙g-1 of As(III), As(V), and F-, respectively, in solution. Even after four cycles, the adsorption of As(III), As(V), and F- remains at 81.11%, 81.36%, and 80.87%, respectively. This study obtained an efficient adsorption material for the co-removal of fluorine and arsenic, providing a theoretical basis and technical support for ensuring the safety of drinking water in remote areas of Northwest China.