Pb(II) Uptake from Polluted Irrigation Water Using Anatase TiO2 Nanoadsorbent

Vasquez-Caballero M.A.; Canchanya-Huaman Y.; Mayta-Armas A.F.; Pomalaya-Velasco J.; Checca-Huaman N.-R.; Bendezú-Roca Y.; Ramos-Guivar J.A. · Molecules (2023) · DOI: 10.3390/molecules28124596

Resumen

The adsorption characteristics of titanium dioxide nanoparticles (nano-TiO2) for the removal of Pb(II) from irrigation water were investigated in this work. To accomplish this, several adsorption factors, such as contact time and pH, were tested to assess adsorption efficiencies and mechanisms. Before and after the adsorption experiments, commercial nano-TiO2 was studied using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The outcomes showed that anatase nano-TiO2 was remarkably efficient in cleaning Pb(II) from water, with a removal efficiency of more than 99% after only one hour of contact time at a pH of 6.5. Adsorption isotherms and kinetic adsorption data matched the Langmuir and Sips models quite well, showing that the adsorption process occurred at homogenous sites on the surface of nano-TiO2 by forming a Pb(II) adsorbate monolayer. The XRD and TEM analysis of nano-TiO2 following the adsorption procedure revealed a non-affected single phase (anatase) with crystallite sizes of 9.9 nm and particle sizes of 22.46 nm, respectively. According to the XPS data and analyzed adsorption data, Pb ions accumulated on the surface of nano-TiO2 through a three-step mechanism involving ion exchange and hydrogen bonding mechanisms. Overall, the findings indicate that nano-TiO2 has the potential to be used as an effective and long-lasting mesoporous adsorbent in the treatment and cleaning of Pb(II) from water bodies.

Instituciones: Universidad Nacional Mayor de San Marcos; Universidad Nacional del Centro del Perú