Metal organic framework–derived recyclable magnetic coral Co@Co3O4/C for adsorptive removal of antibiotics from wastewater

Abstract

The menace posed by antibiotic contamination to humanity has increased due to the absence of efficient antibiotic removal processes in the conventional waste water treatment methods from the hospitals, households, animal husbandry, and pharma industry. Importantly, only a few commercially available adsorbents are magnetic, porous, and have the ability to selectively bind and separate various classes of antibiotics from the slurries. Herein, we report the synthesis of a coral-like Co@Co 3 O 4 /C nanohybrid for the remediation of three different classes of antibiotics — quinolone, tetracycline, and sulphonamide. The coral like Co@Co 3 O 4 /C materials are synthesized via a facile room temperature wet chemical method followed by annealing in a controlled atmosphere. The materials demonstrate an attractive porous structure with an excellent surface-to-mass ratio of 554.8 m 2 g −1 alongside superior magnetic responses. A time-varying adsorption study of aqueous nalidixic acid solution on Co@Co 3 O 4 /C nanohybrids indicates that these coral-like Co@Co 3 O 4 /C nanohybrids could achieve a high removal efficiency of 99.98% at pH 6 in 120 min. The adsorption kinetics data of Co@Co 3 O 4 /C nanohybrids follow a pseudo-second-order reaction kinetics suggesting a chemisorption effect. The adsorbent has also shown its merit in reusability for four adsorption-desorption cycles without showing significant change in the removal efficiency. More in-depth studies validate that the excellent adsorption capability of Co@Co 3 O 4 /C adsorbent attributing to the electrostatic and π–π interaction between adsorbent and various antibiotics. Concisely, the adsorbent manifests the potential for the removal of a wide range of antibiotics from the water alongside showing their utility in the hassle-free magnetic separation. Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s11356-023-25846-4.

Valorization of coffee husks for the sustainable removal of pharmaceuticals from aqueous solutions

“…As more adsorbent is added, there are more sites to bind the CIP molecules, increasing removal until saturation is reached (Nazari et al 2016). The subsequent decline in removal percentage at higher dosages likely occurs due to remaining unsaturated sites after adsorption, reducing the total effective surface area (Bhattacharyya et al 2023). In contrast to the removal percentage trend, the adsorption capacity decreased continuously from 91 mg/g at the lowest dosage tested to 0.5 mg/g at the highest dosage.…”

pH-dependent adsorption of the sulfamethoxazole antibiotic on HKUST-1@CNS nanocomposite corroborating efficiency, mechanistic, and kinetic studies

“…The computed adsorption intensity ( n ) value was found to be between 1 and 10, indicating a favorable adsorption process. 64…”

“…Therefore, the aromatic rings in the NAL molecules and the π-electron network of the graphitic carbon present in the HKUST-1@CNS adsorbent were primarily responsible for the π–π interactions, which influence the adsorption of NAL at higher pH leading to its 71.10% removal. 64…”

Co3O4/activated carbon nanocomposites as electrocatalysts for the oxygen evolution reaction

“…These results are consistent with XPS data reported for other Co 3 O 4related systems. [73][74][75] A slight decrease of the binding energy (BE) values for Co 3+ and an increase for Co 2+ cations were observed for the Co 3 O 4 /C10 nanocomposite compared to ZIF-67/C10. In addition, as seen in Fig.…”