This study aims to present an effective solution for pollutant treatment after adsorption onto modified bentonite. Modified bentonite has been taken as a medium to divide the treatment process of Congo red (CR) dye by a photo-Fenton process into two different processes (separation of CR from wastewater by adsorption and degradation of CR on the surface of the adsorbent by the photo-Fenton process). The adsorbent was characterized by scanning electronic microscopy, zeta potential, and diffuse reflectance spectroscopy techniques. Batch adsorption experiments were carried out to study the effect of the contact time on the adsorption properties of the dye. Kinetics study and isotherm analysis were conducted. The photo-Fenton regeneration of the adsorbent was investigated under different experimental conditions. The results show the success of the regeneration and the total mineralization of the dye.