Phosphate-adsorbed metal organic framework as a recycled material for catalytic degradation of ceftriaxone sodium via peroxymonosulfate activation.

In this study, the zirconium-based metal organic framework (Zr-MOF) was applied as the adsorbent for phosphorus (P) pollution in water. Then the phosphate-adsorbed metal organic frameworks (MOFs) were used as a recycled raw material and calcined to obtain P-doped MOFs-derived carbon material (ZrP@Zr-BTC). Next, the ZrP@Zr-BTC was used for peroxymonosulfate (PMS) activation for the ceftriaxone sodium degradation. The doping of P species in the MOFs-derived carbon material led to a 31 % increase in the degradation rate compared to the material without P doping (ZrO@Zr-BTC). The characterization results confirmed that ZrP@Zr-BTC contained zirconium phosphate, ZrP and ZrO in addition to inorganic carbon. P doping could affect the morphology of zirconium species and the bonding state of oxygen element in the catalyst. The degradation of ceftriaxone sodium by the ZrP@Zr-BTC/PMS system could reach 96 ± 0.82 %. The ZrP@Zr-BTC material also had strong resistance to water quality interference and reusability. The electron spin resonance spectrometer (ESR) analysis indicated singlet oxygen (O) played an important role and other free radicals (SO•, •OH, O•) were auxiliary. The Fukui function calculated by density functional theory explained the sites susceptible to attack by reactive species, and liquid chromatography-mass spectrometry (LC-MS) results allowed for the inference of the degradation pathway of ceftriaxone sodium. This study not only provides a simple and effective method for the disposal and recycling of waste adsorbents but also offers valuable insights into the role of MOF-derived carbon in activating PMS for pollutant degradation.