Adsorption onto activated carbon is one of the most feasible techniques for micropollutants removal from water. Nevertheless, the sustainability and economy of this process is strongly limited by the difficult regeneration of the saturated adsorbents, which, in practice, are commonly disposed. This work aims to tackle this challenge by the development of a granular activated carbon (GAC) decorated with magnetite nanoparticles (Fe3O4/GAC), that allows the in-situ regeneration of the saturated solid by H2O2 addition (through heterogeneous Fenton oxidation). Its performance was tested in a fixed-bed column in continuous operation using the pharmaceutical diclofenac (DCF) as target pollutant. The adsorbent was synthesized by the incorporation of 5% wt. iron to commercial granular activated carbon (GAC) by incipient wetness impregnation, followed by calcination and reduction. The immobilization of magnetite nanoparticles did not significantly alter neither the specific surface area (∼1000 m2 g−1) nor the main properties of the solid, which was fully characterized. Accordingly, its adsorption capacity remained practically unchanged (∼400 mg g−1). Remarkably, the addition of H2O2 allowed to restore the adsorption capacity of the adsorbent at 25 ºC using a H2O2 dose of 3 - 6 g L−1 during 20 h. In-situ regeneration was demonstrated in three consecutive adsorption-regeneration runs for the treatment of 100 mg L−1 DCF, obtaining similar breakthrough curves. Notably, iron leaching was practically negligible during operation and was below 2% wt. of the solid along the regeneration treatment. As a proof of concept, the feasibility of the system was finally proved in the treatment of a representative concentration of DCF (500 µg L−1). The adsorbent led to the complete removal of the pollutant along 10 days and was effectively regenerated after saturation in just 3 h.