Zirconium-silver modified zeolite for fluoride and pathogen removal from drinking water: Synthesis, characterization, and adsorption modelling

Abstract

This study successfully synthesized Zr 4+ /Ag + bimetal oxides modified zeolite for use in fluoride and pathogen removal from drinking water. Calcined bentonite was subjected to ultrasound-assisted alkali dissolution followed by hydrothermal treatment in the presence of 0.5 M and 0.3 M of ZrCl 4 and AgNO 3 , respectively. The obtained material was characterized using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Fourier Transform Infrared (FTIR), and Scanning Electron Microscopy Energy Dispersive Spectroscopy (SEM-EDS). The efficiency of the synthesized zeolite in removing fluoride and pathogens was evaluated through batch fluoride adsorption and well-assay diffusion experiments, respectively. A maximum fluoride removal percentage of ≈50% was achieved under optimal pH conditions of 6 ± 0.5, a contact time of 270 min, an initial fluoride concentration of 6.2 mg/L, and an adsorbent dosage of 0.5 g/100 mL. The synthesized material was successfully regenerated for up to 6 successive regeneration-reuse cycles. Furthermore, the antimicrobial potency results showed a minimum zone of inhibition of 15 mm and 12 mm against the gram-negative E. coli and the gram-positive S. aureus strains, respectively. This study demonstrated that the Zr 4+ /Ag + -modified zeolite has potential for removing fluoride and pathogens from groundwater.