Antibiotics have been extensively used in medicine and aquaculture, leading to severe environmental contamination. Among them, chlortetracycline (CTC) has attracted considerable attention due to its large consumption and high residual risk. MIL-125(Ti), as a representative titanium-based metal–organic framework, exhibits good structural stability and tunability; however, its intrinsically weak visible-light response and rapid charge recombination limit further photocatalytic applications. To improve its photocatalytic performance, MIL-125 was first synthesized via a hydrothermal method, and then Fe and S species were introduced through a combination of in situ coprecipitation and mild sulfuration, yielding an Fe/S-modified MIL-125 photocatalyst. The introduction of Na₂S induced defect sites and coordinatively unsaturated centers on the MIL-125 surface, while the cooperative participation of Fe species further regulated the surface electronic structure and active-site distribution, thereby enhancing visible-light absorption and interfacial charge transfer. Under AM 1.5 irradiation, the optimized Fe/S-MIL-125 achieved a CTC degradation efficiency of 98.6% within 120 min at an initial concentration of 40 mg L−1. In addition, the material exhibited broad applicability toward multiple antibiotics, with degradation efficiencies exceeding 87% for ciprofloxacin (CIP) and clindamycin (CLI). Cycling tests demonstrated that the catalyst retained high activity after five successive runs, indicating excellent stability. Radical scavenging experiments and ESR analyses revealed that superoxide radicals (·O²⁻) were the dominant reactive species. Overall, the Fe/S-modified strategy significantly enhanced the photocatalytic performance of MIL-125 through defect engineering and interfacial charge regulation, offering a promising approach for the design of MOF-based materials for antibiotic removal.

Compared with the results of experiments,the effect of PSB on dairy waste water treatment and influencing factors were studied.The experimental results show that the removal efficiency of COD and BOD₅ in dairy wastewater by PSB is much higher than the traditional methods.Under the anaerobic acidification-semi micro oxygen and semi-darkness conditions,the removal efficiency of COD is better than that under anaerobic light-illumination and aerobic darkness conditions. The optimal conditions are that the temperature is controlled between 15°C and 30°C,and the value of pH is 6.5-8.5, and the volume ration of wastewater and bacterial liquid is at 3:1,and DO in system is about 0.1-0.8mg/L.The stable water quality and higher removal efficiency of COD and BOD5 provide the basis for the further treatment of high concentration organic wastwater.

Tetracycline-class antibiotics are persistent contaminants in aquatic environments and are difficult to remove by conventional treatment processes. In this study, a recoverable granular MIL-101(Fe)/γ-Al₂O₃ catalyst was prepared through ligand anchoring followed by secondary Fe-MOF growth on spherical γ-Al₂O₃ and applied to catalytic ozonation of tetracycline (TC) under ordinary-bubble and microbubble-assisted operation. Structural characterization supported the formation of Fe-containing MOF domains on the alumina support, accompanied by an increase in BET surface area from 164.28 to 210.05 m² g⁻¹ and enhanced Lewis-acid-related pyridine-IR signals. Under conventional bubbling ozonation, the optimized catalyst achieved 67.93% apparent UV–Vis-based TC removal during an overall 50 min run consisting of 30 min dark adsorption followed by 20 min ozonation. In a 12 L microbubble reactor, the catalyst-assisted system reached 93.74% apparent UV–Vis-based TC removal at pH 6 with 100 g catalyst and 6 mg min⁻¹ fed ozone, showing higher apparent removal than ordinary ozonation, microbubble ozonation, and ordinary-bubble catalytic ozonation under the tested configuration. Phosphate-blocking and radical-quenching experiments were consistent with the involvement of Lewis-acid-related sites, hydroxyl radicals, and superoxide-related pathways, but these tests are interpreted as indirect mechanistic evidence. LC-MS analysis suggested possible hydroxylation, demethylation, deamidation, ring opening, and low-molecular-weight product formation. The system also transformed chlortetracycline, oxytetracycline, and doxycycline and reduced COD and TOC in a simulated mixed-antibiotic matrix. Because parent-compound HPLC/LC-MS time-series quantification, ozone utilization/off-gas ozone measurement, bubble-size/kLa analysis, and ICP-based Fe loading/leaching data were not available, the present work is positioned as an apparent catalyst–reactor coupling study rather than a complete catalytic, hydrodynamic, or process-level demonstration.