Adsorptive performances of magnetic graphene oxide adsorbent for the removal of fluoroquinolones in the Langat River Basin, Malaysia

The presence of pharmaceuticals in aquatic systems is a matter of great concern. As a result of their high solubility and low volatility, their removal has been very challenging. In this work, the synthesis, characterisation and adsorption study of graphene oxide-based magnetic nanoparticles (GO@Fe3O4) were explored for the removal of fluoroquinolones (FQs). GO@Fe3O4 adsorbent was synthesised by a one-step co-precipitation method using ammonium ferrous sulphate ((NH4)(2)FeSO4) and ferric chloride hexahydrate (FeCl3 center dot 6H(2)O) as iron sources and ammonium solution as precipitant. The removal of four FQs (ofloxacin, enrofloxacin, sparfloxacin. and gemifloxacin) by GO@Fe3O4 adsorbent was explored. The effect of contact time, initial pH of the solution, initial FQs concentration on the removal efficiency, and reusability were investigated. The pseudo-second-order kinetic model represented the adsorption process for GO@Fe3O4 adsorbent. The Freundlich isotherm model was a better fit with adsorption capacities of 44.4, 40.8, 64.0, and 51.8 mg/g for ofloxacin, enrofloxacin, sparfloxacin, and gemifloxacin, respectively. Under optimised conditions, GO@Fe3O4 adsorbent was successfully applied for the removal of FQs in water samples from the Langat River basin. The results showed enhanced sorption capacity and high removal efficiency towards for FQs removal from an aqueous solution and has the potential to be an alternative adsorbent.