(453f) Novel Porous Ternary Mg-Al-Ti Oxide Composite Nano-Adsorbents with Extremely High Arsenic Removal Capacity

Arsenic pollution of groundwater is a menacing issue in various parts of India as well as the entire world due to its toxicity and carcinogenicity. Removal of heavy metals from water by adsorption is one of the most effective approaches for its cost-effectiveness, ease of operation, high efficiency, process simplicity, and easy regeneration of materials. Porous materials are efficient adsorbents as they offer a large surface area for fast mass transfer and more active adsorption sites which result in high adsorption capacity. In this work, porous ternary Mg-Al-Ti oxide composites were synthesized by evaporation induced self-assembly using tri-block copolymer as soft-template. Composites with various elemental compositions were calcined at 400^oC and 900^oC to study performance and morphological differences. The 400^oC calcined Aluminium rich composites showed high As(V) uptake efficiency of 265.6 mg/g, Magnesium-rich composites showed extremely high uptake of 1215 mg/g, and Titanium rich composites showed high uptake of 329 mg/g at pH~8 and 0.5g/L dose. Nanoparticles were characterized by XRD, SEM-EDX, BET surface area, N₂ adsorption isotherm. The BET surface areas were found to be 151.3 m² /g and 74.5 m² /g for 900^oC calcinated Aluminum and Magnesium-rich samples respectively. SEM image and hysteresis loop in N₂ adsorption isotherm proved the porous nature. Detailed characterization and experiments were done to understand the adsorption mechanism and regeneration ability of the composites. The adsorption capacity of Mg-rich composite is significantly higher than the previously reported adsorbents. Due to their porous nature and extremely high adsorption capacity, the composites are promising candidates for arsenic removal through adsorptive and membrane assisted processes.