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This work investigated the efficiency of CoFe2O4 nanoparticles in removing diclofenac and naproxen drugs from aqueous solutions. At first, the Taguchi method was performed to choose the most important factors among the investigated factors affecting the removal efficacy of these drugs. Afterward, the optimal conditions of the effective factors were investigated and modeled by the central composite design-based response surface method. The results revealed that the maximum drug removal was obtained at pH = 7, temperature of 25 °C, adsorbent dosage of 215 mg, sonication time of 21 min, and diclofenac and naproxen concentrations of 15 mg L−1. The removal efficacy of diclofenac and naproxen under these optimal conditions was 99.42 % and 95.11 %, respectively. Based on the results, it is concluded that CoFe2O4 nanoparticles can be applied as an easy-available and effective adsorbent for removing diclofenac and naproxen from water samples.

Abstract The contamination of the aquatic environment with antibiotics is among the major and developing problems worldwide. The present study investigates the potential of adsorbent magnetite-chitosan nanoparticles (Fe3O4/CS NPs) for removing trimethoprim (TMP) and sulfamethoxazole (SMX). For this purpose, Fe3O4/CS NPs were synthesized by the co-precipitation method, and the adsorbent characteristics were investigated using XRD, SEM, TEM, pHzpc, FTIR, and VSM. The effect of independent variables (pH, sonication time, adsorbent amount, and analyte concentration) on removal performance was modeled and evaluated by Box–Behnken design (BBD). The SEM image of the Fe3O4/CS adsorbent showed that the adsorbent had a rough and irregular surface. The size of Fe3O4/CS crystals was about 70 nm. XRD analysis confirmed the purity and absence of impurities in the adsorbent. TEM image analysis showed that the adsorbent had a porous structure, and the particle size was in the range of nanometers. In VSM, the saturation magnetization of Fe3O4/CS adsorbent was 25 emu g−1 and the magnet could easily separate the adsorbent from the solution. The results revealed that the optimum condition was achieved at a concentration of 22 mg L−1, a sonication time of 15 min, an adsorbent amount of 0.13 g/100 mL, and a pH of 6. Among different solvents (i.e., ethanol, acetone, nitric acid, and acetonitrile), significant desorption of TMP and SMX was achieved using ethanol. Also, results confirmed that Fe3O4/CS NPs can be used for up to six adsorption/desorption cycles. In addition, applying the Fe3O4/CS NPs on real water samples revealed that Fe3O4/CS NPs could remove TMP and SMX in the 91.23–95.95% range with RSD (n = 3)

This study investigates the efficient removal of ciprofloxacin (Cip) and cephalexin (Cep) using magnetic graphene oxide (Fe3O4/GO) as an adsorbent. To this end, the magnetic nanocomposite was synthesized via a co-precipitation method. The surface and properties of the adsorbent were characterized using pHpzc, XRD, FE-SEM, FT-IR, VSM, and TEM techniques. The XRD and FT-IR results were consistent with those of previous results. The FE-SEM and TEM results of the synthesized nanoparticles were less than 30 nm in size and showed a spherical shape. The maximum saturation magnetization of the Fe3O4/GO nanocomposite was 45.97 emu g−1. Also, the pHpzc of the nanocomposite was 6.2. The optimal conditions for independent variables were found to be an antibiotic concentration of 15 mg L−1, pH of 7, a contact time of 33 min, and a nanocomposite amount of 0.55 g. Furthermore, under these optimal conditions, Fe3O4/GO magnetic nanocomposite removed 96.39 % of Cip and 97.69 % of Cep from the water samples. Among different eluents (i.e., acetonitrile, chloroform, methanol, and ammonia), significant desorption of Cip and Cep antibiotics was achieved using methanol. Furthermore, applying the Fe3O4/GO magnetic nanocomposite on real water samples revealed that nanocomposite could remove Cip and Cep antibiotics in the range of 89.96–95.83 %. Considering the high potential of Fe3O4/GO magnetic nanocomposite in removing Cip and Cep antibiotics, it can be considered a suitable candidate for removing antibiotics from contaminated water sources.