Design of Magnetic Nanotechnological Devices to the Removal of Fluoride from Groundwater

V. N. SCHEVERIN; A. V. RUSSO; M.F. HORST; S. E. JACOBO; V. L. LASSALLE

Buenos Aires

Conferencia; 2nd Latin American Conference On Sustainable Development Of Energy, Water and Eviroment Systems; 2020

The presence of fluoride in water resources represents a great riskto public health, because of its excessive intake over a long period may resultin a disease named fluorosis. More than 200 million people in the world areestimated that are exposed to fluoride concentration higher than the value recommendedby WHO in drinking water (1,5 mg/L). The adsorption process is one of the mostpromising technology for the removal of fluoride due to its low cost,simplicity of application and operation. Zeolites are recognized as efficient adsorbentmaterial being of natural origin and low cost. However, its anion removalcapacity is limited because of their extremely negative surface charge atalmost the complete pH range. The aim of this work is to synthesize adsorbentmaterials based on natural zeolite (Z) and magnetite nanoparticles (M). Mcontributes providing suitable separation properties improving their reusabilityperspectives. A surface modification using aluminium and calcium has beenimplemented aiming to enhance the affinity with fluoride in the groundwatermedia.The surface of natural Zeolite (Z), a zeolite with zero valent iron(ZAFe), magnetite nanoparticles (M) and a composite based on zeolite andmagnetite (MZ) were modified with Al and Ca. For thispurpose, each material was dispersed into a solution of potassium aluminumsulfate and calcium sulfate with a w/w ratio of 1:2:0.5 respectively. The suspensionpH was adjusted in a range 7-8 with NaOH and stirred during 3h at r.t. All thematerials were physicochemically characterized. The performance of MZ influoride removal was tested using a model solution of F- with aconcentration of 6 mg/L at pH 8 (±0.2) employing a relation4:1 (adsorbent/ volume of F- solution).The kinetic studies indicated the efficiencyof F- removal reached values over 94% in the first 5 min oftreatment using all Al-Ca modified materials. On the other hand, the samematerials without surface modification resulted inefficient for F- removalunder identical conditions.Results obtained within this work suggest thatthe surface modification resulted relevant to assess rapid and effective fluorideuptake, demonstrating the potential utility of this adsorbents, especially ZMbecause of its properties regarding separation by magnetic field. Additionalstudies are currently in development and include the stability and reusabilityproperties of the prepared materials.