Coordination And Photochemical Transformation Of Environmental Drugs On The Surface Of Iron-containing Particles

In recent years,researchers have found thousands of new drug contaminants in soil,groundwater,surface and seawater.In some cases,levels of antibiotics and anti-inflammatory drugs can reach hundreds of nanograms per liter in terrestrial and aquatic environments.Environmental drugs not only destroy balance of nature,but also cause harmful effects on human health,which has aroused great attention.The degradation technology of antibiotics and anti-inflammatory drugs has also become the research content of more and more scholars.Nalidixic acid（NA）and non-steroidal anti-inflammatory drug acid（NFA）in quinolones were used to degrade NA and NFA in aqueous Iron（II）sulfide.The Iron（II）sulfide is used for safety and economic reasons in practical applications.The coordination and photochemical conversion of NA and NFA on Iron（II）sulfide surfaces in the environment were studied.The relative factors affecting the degradation of NA and NFA（NA concentration,NFA concentration,p H,Iron（II）sulfide dosage）and the determination of free radicals in the reaction system（hydroxyl radical,singlet oxygen,superoxide anion,etc.）were identified,the products of oxidation degradation of NA and NFA in the reaction system were analyzed by LC-MS to infer the degradation process of NA and NFA in the reaction system.According to the experimental results,the following conclusions were obtained:FeS can adsorb NA and NFA in aqueous solution,UV light can enhance the surface adsorption and oxidation,promote the degradation of NA and NFA.The initial concentration of NA and NFA was 10μm,the p H value of the reaction system was 5,the amount of Iron（II）sulfide was 0.5 g L^-1.The degradation of NA and NFA was inhibited by adding ethanol and Disodium phosphate to the reaction system Adding furfuryl alcohol,tetrachloromethane and p-benzoquinone into the reaction system had no obvious inhibition on the degradation of NA and NFA,adding oxygen to the reaction system promoted the degradation of NA and NFA,and adding nitrogen to the reaction system,inhibit the degradation of NA and NFA.In this study,the adsorption and photolysis mechanisms of NA and NFA in single and mixed Iron（II）sulfide systems were elucidated,which may help to determine the conditions under which co-binding of drugs may be prevalent in the environment.Adsorption and photolysis through synergistic drug interaction may also lay the foundation for an emerging mechanism for polluting the environment.To provide a novel and effective method for degrading antibiotics and anti-inflammatory drugs.