Adsorption Behavior and Mechanistic Study of Arsenic Removal from Water Using Lanthanum Cobalt Ferrite Nano Composite Materials

The presence of arsenic in water bodies is one of the most important environmental and public health issues worldwide because of its persistence, toxicity, and cancer-causing properties. Water treatment technologies have been widely used have some drawbacks such as low efficiency, low selectivity, high water treatment cost and the loss of adsorbents. Lanthanum cobalt ferrite (LaCoFe) nanocomposite materials have been at the centre of much recent attention as potentially good adsorbent due to their high surface area, large number of active sites, magnetic separability and the good affinity for arsenic species. The present study is an in-depth study of the behaviour of adsorption and the mechanism of the removal of arsenic from an aquuous system using lanthanum cobalt ferrite nanocomposite material for its secondary research analysis. Literature search in scientific peer-reviewed journal from main scientific databases was conducted systematically to evaluate the effect of most operational parameters like solution pH, contact time, initial concentration of arsenic, adsorbent dosage, temperature, adsorption isotherm, adsorption kinetic and adsorption thermodynamic parameters. All of the studies reviewed demonstrated the good adsorption properties of lanthanum cobalt ferrite nanocomposites with optimization conditions that showed the adsorption mechanism was mainly monolayer adsorption and chemisorption according to the Langmuir isotherm and pseudo-second-order kinetic model. Furthermore, thermodynamic studies reported in the literature showed that the adsorption process is generally endothermic and spontaneous and mechanistic studies showed that the removal of arsenic is mainly attributed to electrostatic interactions, surface complexation, ligand exchange, ion exchange and pore diffusion. The magnetic property of the nanocomposite also supports the efficient separation and regeneration of the composite material and hence it is a potential material for water treatment application. Based on the results obtained, it can be concluded that lanthanum cobalt ferrite nanocomposites can be promising adsorbents for arsenic remediation that are sustainable and efficient. The review contributes to the existing knowledge by highlighting the current advancements in the mechanism of adsorption and suggesting future research directions, including application at the macro-scale, regeneration efficiency of the adsorbents, stability, and environmentally friendly synthesis methods of advanced nanocomposite adsorbents.