Optimization of removal of sulfonamide antibiotics by magnetic nanocomposite from water samples using central composite design

The present study aimed to remove sulfonamide antibiotics from water samples using magnetic Fe3O4-bentonite nanocomposite (Fe3O4-Bt) as an adsorbent. The adsorbent has a surface area of 74.27 m(2) g(-1), a pore size of 87.53 nm, and a pore volume of 0.146 cm(3) g(-1). A central composite design (CCD) matrix was employed to model and optimize the process. The optimal conditions for removing sulfonamide antibiotics were determined using Fe3O4-Bt adsorbent at an antibiotic concentration of 20 mg L-1, the amount of nanoparticles of 0.23 g, pH of 6, and ultrasonication time of 17 min. The reusability study of the Fe3O4-Bt adsorbent showed that the Fe3O4-Bt could be used five times in adsorption/desorption processes. Also, applying the Fe3O4-Bt adsorbent on real samples revealed that Fe3O4-Bt adsorbent could remove sulfonamide antibiotics in the range of 86.85-97.47% with RSD (n = 5) < 4.