Magnetic cobalt and nickel oxide nanoparticles for excellent arsenic withdrawal from water.

Groundwater arsenic mobilizations through multi-faucet channels pose a threat to living beings. To combat this, a self-reliant auto-combustive preparation route of magnetic cobalt and nickel oxide nanoparticles (CONP and NONP, respectively) was adopted and tested successfully to scavenge arsenic from contaminated water. FESEM-EDX was used to confirm the adsorption whereas the uptake process has been optimized concerning reaction adaptabilities such as contact time, concentration, and pH effects. The maximum adsorption capacity at neutral pH with CONP is 166.67 mg/g whereas NONP enjoys an edge with 200 mg/g. The pseudo-second-order kinetic model (R² = 0.999) and Langmuir isotherm model (R² = 0.999) are the best fit for the uptake process of arsenic. Thermodynamic assessment suggests a spontaneous (∆G = − 9.916 kJ/ mol), endothermic (∆H = − 8.016 kJ/mol) process with limited randomness (∆S = 0.086 J/K.mol) at the solid–solution interface. Regeneration was achieved with dilute sulfuric acid, and the reusability test suggests retention of about 80% efficiency after five cycles. Comparative assessment with other recently reported materials strongly suggests the superiority of the present materials. The process is economically viable, sustainable, clean, and green which provides an alternative to scavenge arsenic better than any contemporary ones. [ABSTRACT FROM AUTHOR]