Remediation of ibuprofen and naproxen in water by a green composite material of magnetic carbon nanotube-metal-organic framework

This work adopted a simple and green method for synthesizing a composite of magnetic carboxylic multi-walled carbon nanotube-metal-organic frame (MCNTs-UiO-66-NH2) at room temperature, which was applied to the remediation of ibuprofen (Ibu) and naproxen (Nap) in wastewater. The influencing factors of adsorption were investigated, including adsorbent dosage, pH value, coexisting ions, temperature, and contact time, etc. Various methods were employed for analyzing the structural features and surface characteristics exhibited by MCNTs-UiO-66-NH2. The values of max adsorption quantity about MCNTs-UiO-66-NH2 toward Ibu and Nap reached 143 mg center dot g-1 and 139 mg center dot g-1 at 313 K, respectively. The Langmuir model and Pseudo-second-order model can describe the adsorption process of Ibu and Nap. According to the values of the thermodynamic parameters, both adsorption processes were endothermic, spontaneous and could lead to an increase in entropy. In addition, the composite can be used to capture Ibu and Nap in the pH range of 1-10 and the salinity range of 0-0.2 mol center dot L-1 with an ideal regeneration performance taking 5 mmol center dot L-1 NaHCO3 as eluent. The mechanism of adsorption is including complexation, 7C-7C conjugation, electrostatic action and H-bonding. These properties confirm MCNTs-UiO-66-NH2 as one potential adsorbent for remediation of Ibu and Nap in wastewater.

Automated summary

This study presents a simple and environmentally friendly method to synthesize a new composite material MCNTs-UiO-66-NH2, which was applied for the remediation of ibuprofen and naproxen in wastewater. The structural and surface characteristics of the composite material were analyzed using various methods. The results showed that the composite material exhibited high adsorption capacity and could capture and regenerate the target substances under different conditions. The adsorption mechanism was also revealed.