Facile synthesis of CoFeO@MIL-53(Al) nanocomposite for fast dye removal: Adsorption models, optimization and recyclability.

The global occurrence of textile dyes pollution has recently emerged, posing a serious threat to ecological systems. To abate dye contamination, we here developed a novel magnetic porous CoFeO@MIL-53(Al) nanocomposite by incorporating magnetic CoFeO nanoparticles with MIL-53(Al) metal-organic framework. This nanocomposite possessed a surface area of 197.144 m g and a pore volume of 0.413 cm g. The effect of contact time (5-120 min), concentration (5-50 mg L), dosage (0.1-1.0 g L), and pH (2-10) on Congo red adsorption was clarified. CoFeO@MIL-53(Al) could remove 95.85% of Cong red dye from water with an accelerated kinetic rate of 0.6544 min within 10 min. The kinetic and isotherm models showed the predominance of Bangham and Temkin. According to Langmuir, the maximum uptake capacities of CoFeO@MIL-53(Al), CoFeO, and MIL-53(Al) adsorbents were 43.768, 17.982, and 15.295 mg g, respectively. CoFeO@MIL-53(Al) was selected to optimize Cong red treatment using Box-Behnken experimental design. The outcomes showed that CoFeO@MIL-53(Al) achieved the highest experimental uptake capacity of 35.919 mg g at concentration (29.966 mg L), time (14.926 min), and dosage (0.486 g L). CoFeO@MIL-53(Al) could treat dye mixture (methylene blue, methyl orange, Congo red, malachite green, and crystal violet) with an outstanding removal efficiency of 81.24% for 30 min, and could be reused up to five cycles. Therefore, novel recyclable and stable CoFeO@MIL-53(Al) is recommended to integrate well with real dye treatments systems.