Adsorption of nitrophenol onto a novel Fe₃O₄-κ-carrageenan/MIL-125(Ti) composite: process optimization, isotherms, kinetics, and mechanism.

ABSTRACT: Water pollution is a dreadful affair that has incessantly aggravated, exposing our planet to danger. In particular, the persistent nitro aromatic compound like nitrophenols causes anxiety to the researchers due to their hazardous impacts, excessive usage, and removal difficulty. For this purpose, a novel multi-featured composite was constructed based on κ-Carrageenan (κ-Carr), MOF (MIL-125(Ti)), and magnetic Fe₃O₄ for efficient adsorptive removal of o-nitrophenol (o-NP). Interestingly, BET measurements revealed the high surface area of Fe₃O₄-κ-Carr/MIL-125(Ti) of about 163.27 m²/g, while VSM showed its excellent magnetic property (20.34 emu/g). The comparison study pointed out the synergistic effect between Fe₃O₄, κ-Carr, and MIL-125(Ti), forming a composite with an excellent adsorption performance toward o-NP. The adsorption data obeyed pseudo-second-order kinetic model, and Freundlich isotherm model was better fitted than Langmuir and Temkin. Furthermore, Langmuir verified the supreme adsorption capacity of o-NP onto Fe₃O₄-κ-Carr/MIL-125(Ti) since the computed q_max reached 320.26 mg/g at pH 6 and 25 °C. Furthermore, the XPS results postulated that the adsorption mechanism pf o-NP proceeded via H-bonding, π-π interaction, and electron donor-acceptor interactions. Interestingly, Fe₃O₄-κ-Carr/MIL-125(Ti) composite retained good adsorption characteristics after reusing for five cycles, suggesting its viable applicability as an efficient, renewable, and easy-separable adsorbent for removing nitro aromatic pollutants.

SUBMITTER: Abd El-Monaem EM 

PROVIDER: S-EPMC10104928 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature