Zirconium oxide-loaded granular activated carbon (Zr-GAC) was prepared for the adsorption of sulfate ions in aqueous solution. The Zr-GAC was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelecton spectroscopy (XPS), and specific surface area measurement. The results showed that the Zr-GAC had a porous surface with many aggregates, composed of zirconium oxides. XPS analysis confirmed the massive presence of zirconium and hydroxyl groups in the adsorbent surface. The specific surface area of the activated carbon decreased after modification with zirconium oxides. Batch adsorption experiments were conducted to determine the effect of pH on sulfate adsorption, and it was found that better adsorption could be achieved at pH lower than 10. Modeling analysis of the adsorption isotherms showed that the Dubinin-Radushkevich (D-R) equation had better fittings than the Langmuir model, and the maximum adsorption capacity of the Zr-GAC determined by the D-R equation was 70.14 mg/g in neutral water solution, much higher than that of raw GAC (8.9 mg/g). The D-R equation may have a problem in determining the adsorption energy for a solution adsorption, which deserves more research. Kinetic studies show that the adsorption of sulfate on the Zr-GAC is relatively fast, and it follows the pseudo second-order kinetic equation. In addition, an increase of temperature may facilitate the sulfate adsorption, to some extent. The Zr-GAC showed good potential for the adsorption of sulfate ions in aqueous solution. It exhibited approximately twice the adsorption capacity and a much wider applicable range of pH compared with the zirconium-loaded biochar adsorbent.