Synthesis and Characterization of Magnetic Xerogel Monolith as an Adsorbent for As(V) Removal from Groundwater

Abstract

Arsenic contamination of groundwater is still a global problem due to the toxicity at low dose on human health confirmed by epidemiological studies. Magnetic xerogel monoliths (MXs) were synthesized by the sol-gel polymerization using resorcinol, formaldehyde, alkaline catalyst and magnetite. The varying molar ratios of magnetite and resorcinol (M/R) in the gel were evaluated for As(V) removal from groundwater. The surface chemistry, structure and morphology of MXs related to arsenic adsorption were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and point of zero charge. Batch adsorption experiments were carried out to investigate the effects of Fe contents, initial pH and adsorbent dose on As(V) removal performance. The MXs with molar ratio of M/R at 0.15 gave the maximum As(V) adsorption capacity and removal with values of 62.8 µg/g and 86.7%, respectively. The adsorption data were well described by the Elovich equation of the kinetic model and the Freundlich isotherm. The thermodynamic studies demonstrated that the adsorption process was endothermic and spontaneous in nature. MXs showed to be a good alternative for As(V) removal from groundwater and achieving the efficient desorption, and thus fulfilled the Mexican standard for drinking water.

Removal of As(V) from aqueous solutions using calcium-alginate microspheres with encapsulated iron nanoparticles

“…It is an effective and efficient method, particularly at low pollutant concentrations, and is relatively simple to implement and operate. In addition, the use of low-cost adsorbents with high removal efficiency makes adsorption a cost-effective process that does not require high energy consumption, does not produce toxic effluents, and does not produce high sludge volumes that would require further treatment (Khamkure et al 2021).…”

Optimizing the performance of As(III) and As(V) adsorption process on magnetic carbon xerogel nanocomposites from aqueous solution and natural groundwater wells

“…The adsorption enthalpy and the effect of temperature were determined using the optimal values resulting from the implemented experimental design and application of groundwater. Most of the investigations of xerogel carbons for water treatment were applied for aqueous solution however few relevant studies used groundwater for the removal of arsenic contamination by using magnetite and magnetite nanoparticle composite of xerogels (Khamkure et al 2021(Khamkure et al , 2022. To our knowledge, this is the rst study to apply magnetite nanoparticles incorporating xerogel carbons with direct sonication for As(III) and As(V) removal from natural groundwater.…”