Novel zirconia-halloysite nanotube material for arsenite adsorption from water

Abstract

Drinking water contaminated with arsenic for a long time will lead to serious human health problems. In this work, to extract arsenite (As(III)) from water, zirconia (ZrO2) loaded on halloysite nanotubes (ZrO2/HNTs) was prepared. ZrO2 nanoparticles were well dispersed on ZrO2/HNTs, and the ZrO2 in this nanohybrid was present in a monoclinic phase. The nanohybrid demonstrated a strong As(III) adsorption capacity (36.08 mg/g) because of the large number of readily accessible hydroxyl groups and its large surface area. The As(III) adsorption on ZrO2/HNTs matched the pseudo-second-order kinetic model and the Langmuir isotherm model, and it was independent of the solution pH. Applying the Dubinin-Radushkevich isotherm model verified that the As(III) removal processes were chemisorption reactions. Studies utilizing X-ray photoelectron spectrometry and Fourier transform infrared analysis revealed that Zr-OH bonds had a significant role in the removal of As(III). In addition, the ZrO2/HNTs nanohybrid demonstrated sufficient As(III) adsorption selectivity with the majority of common coexisting ions present. This research demonstrated the potential of ZrO2/HNTs as a material for the treatment of water polluted with arsenic.