Low-concentration antibiotic wastewater is difficult to treat rapidly using conventional photocatalysts. For this reason, this paper simplified the traditional sol–gel method to prepare Fe³⁺-TiO₂/AC composites and characterized the properties of the composites using FT-IR, XRD, SEM, BET, and TEM. The results demonstrated that iron was uniformly dispersed on the surface of the composites, and the activated carbon (AC) was successfully loaded with iron-doped titanium dioxide. Afterward, ciprofloxacin (CIP) was used as the target degradant, and the effects of different activated carbon loadings, iron-doping, pH, initial concentrations, and UV light intensities on the removal of ciprofloxacin were investigated. The repetitive photocatalytic stability of the composites was studied, and the reaction mechanism was explored by using free radical quenching experiments. The results demonstrated that while iron doping reduced the rate at which photogenerated electrons and holes could combine, loading AC increased the usage efficiency of the composites’ adsorption and catalytic active sites. According to the parameter tests, the circumstances that led to the highest CIP degradation efficiency (94.59%) were as follows: 10 mg/L CIP, 0.5 g/L 0.2%Fe³⁺-TiO₂/20%AC, and solution pH of 7 under 40 min of UV light irradiation. In addition, the Fe³⁺-TiO₂/AC composite material has excellent cyclic stability, the degradation rate of CIP can still reach 87.73% at 60 min after four repeated degradation tests under the same conditions. The applicability of this method could be expanded to the treatment of various industrial organic pollutants in water.

Sodium benzenesulfonate was doped into polypyrrole‐modified granular activated carbon (pyrrole‐FeCl₃·(6H₂O)‐sodium benzenesulfonate‐granular activated carbon; PFB‐GAC) with the goal of improving the modified GAC’s ability to adsorb sulfate from aqueous solutions. At a GAC dosage of 2.5 g and a pyrrole concentration of 1 mol L⁻¹, the adsorption capacity of PFB‐GAC prepared using a pyrrole:FeCl₃·(6H₂O):sodium benzenesulfonate ratio of 1000 : 1500 : 1 reached 23.05 mg g⁻¹, which was eight times higher than that for GAC and two times higher than that for polypyrrole‐modified GAC without sodium benzenesulfonate. Adsorption was favored under acidic conditions and high initial sulfate concentrations. Doping with sodium benzenesulfonate facilitated polymerization to give polypyrrole. Sodium benzenesulfonate introduced more imino groups to the polypyrrole coating, and the N⁺ sites improved ion exchange of Cl⁻ and SO₄²⁻ and increased the adsorption capacity of sulfate. Adsorption to the PFB‐GAC followed pseudo‐second‐order kinetics. The adsorption isotherm conformed to the Langmuir model, and adsorption was exothermic. Regeneration using a weak alkali (NH₃·H₂O), which released OH⁻ slowly, caused less damage to the polypyrrole than using a strong alkali (NaOH) as the regeneration reagent. NH₃·H₂O at a concentration of 12 mol L⁻¹ (with the same OH⁻ concentration as 2 mol L⁻¹ NaOH) released 85% of the sorbed sulfate in the first adsorption‐desorption cycle, and the adsorption capacity remained >6 mg g⁻¹after five adsorption‐desorption cycles.