Synergistic Catalytic Degradation Of Oxazolidinone Antibiotics By DBD-Nano Attapulgite/γ-Fe₂O₃ Composites

Oxazolidinone antibiotics is an important class of PPCPs,widely presents in the water environment,which has caused serious pollution to the water environment.Oxazolidinone antibiotic wastewater generally has the characteristics of high pollutant concentration,poor biodegradability and difficulty of conventional biochemical methods.Therefore,it is urgent to find a way to degrade efficiently,rapidly and thoroughly oxazolidinone antibiotics.In this paper,applying DBD-attapulgite/γ-Fe₂O₃catalytic technology to collaborative degrade linezolid,linezolid as the target pollutant is one of oxazolidinone antibiotics which is synthetic.In order to taking full advantage of the active substances（H₂O₂,O₃,OH）,ultraviolet light and acidic conditions in DBD system,the synergistic degradation effect of the system was studied.The prepared composite catalyst was characterized.The effects of initial concentration of linezolid,the amount of compound catalyst and discharge power on the degradation efficiency of linezolid were studied.The concentration of active species produced by the dielectric barrier（DBD）low temperature plasma system was examined.UPLC-MS was used to determine the degradation byproducts of linezolid and provide potential routes of degradation of linezolid.The main results obtained are as follows:（1）The attapulgite/γ-Fe₂O₃ composite catalyst was successfully prepared by hydrothermal method,and was also characterized.The results showed that the shape of attapulgite is still stick-like,and the structure is stable.The composite catalyst still has good adsorption performance and magnetic properties.（2）The degradative effect of linezolid was DBD-attapulgite/γ-Fe₂O₃>DBD>attapulgite.The degradation efficiency of linezolid increased from over 80%to almost100%after adding the catalyst into the dielectric barrier（DBD）low temperature plasma system.After 20 min,the energy utilization increased from 0.007 g/（kW·h）to 0.48g/（kW·h）.（3）The degradation mechanism of the degradation of linezolid by DBD-attapulgite/γ-Fe₂O₃ is that the active substances（H₂O₂,O₃,OH）mainly oxidize the C-O bond,O=CN bond and C-N bond in linezolid,linezolid was further degraded to CO₂,N₂ and H₂O and other small molecules.The results show that DBD-nano-attapulgite/γ-Fe₂O₃ synergistic system is suitable for the degradation of oxazolidinone antibiotics.