Study On The Occurrence And Environmental Behavior Of Antibiotics In The Mid Route Of The South-to-north Water Transfer Project

As an emerging environmental pollutant,antibiotics can spread through environmental media and the food chain to cause the widespread spread of microbial antibiotic substitution(AMR)and resistance genes(ARGs)in the environment,affecting the ecosystem and threatening human health.Supplementary detection of antibiotics in the water-gas solid environment,research on the occurrence of antibiotics in the environment,environmental behavior,ecological risks and health risks,etc.,in order to determine the priority control types of antibiotics and control the resistance cost The research is based on ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS/MS),and uses solid-phase extraction(SPE),ultrasonic-assisted extraction and other separation technologies for the surface water and deposited antibiotics of the main canal water source project of the South-to-North Water Transfer Project.High-performance liquid chromatography-mass spectrometry(UHPLC-MS/MS)combined multi-substance simultaneous detection method for surface water and sedimentary sedimentary sulfonamides(MLs),quinolones(QNs),and tetracyclines(TCs)in the main channel of the South-to-North Water Transfer Project.The content,distribution characteristics and influencing factors of 83 antibiotics in 7 categories of β-lactams(β-Ls),lincosamides(LMs)and polyethers(PEs)are analyzed and studied,and the risk entropy method is used to evaluate them on the ecological risks of different aquatic species and the health risks of people at different ages,the following results have been obtained:(1)Use SPE-UHPLC to detect 83 kinds of antibiotics in water bodies and sediments.Under the conditions of flow rates of 0.2 m L/min and 0.25 m L/min,injection volume of5.0 μL,and methanol and 0.1%(v:v)formic acid aqueous solution as mobile phases,the peak extraction and separation effects are good,and the standard curve is linear Good,with a wide linear range(1～400 ppb),and the linear coefficients R2 are all greater than0.99.The recovery rates of standard addition are 79.3%～115%(water)and 67.2%～129%(sediment),and the detection limits of the method are 0.001～0.35 ng/L(water)and0.001～0.14 ng/g(sediment).,Meet the requirements of quantitative analysis.(2)A total of 31 antibiotics were detected in the water bodies and sediments of the middle route of the South-to-North Water Transfer Project,involving 6 categories;among them,β-Ls was not detected.The concentration of a single antibiotic in the water sample ranges from nd to 18.8 ng/L,and the detected concentration of monomer antibiotics in the sediment is nd to 43 ng/L.Compared with other water sources in China,the concentration of antibiotics in the main canal of the South-to-North Water Diversion Project is nd～43ng/L.Both are low.In terms of seasonal differences,the content of antibiotics in the water body in spring was significantly higher than that in summer;there was no obvious seasonal difference in sediments.From the spatial distribution point of view,the total concentration of antibiotics in the water body shows an increasing trend along the way.The average antibiotic content in each canal section is: Danjiangkou Reservoir,Nanyang Section<Henan Section<Hebei Section<Tianjin and Beijing Section.(3)Through the analysis of composition differences,it is found that the main polluted canal sections of MLs,LMs and PEs are the Henan section,with Zhaozhuang Southeast(ZZDN)and Houxiaotunxi(HXTX)being the most significant,which requires attention;in sediments,There are the most types of antibiotics in the sediments of the Henan section.In autumn,Yaoying(YY)is the main source of MLs in the sediments.These points may be contaminated by antibiotics for a long time,so attention should be paid.(3)The more hydrophilic LMs(log Kow = 0.56～2.16)the loading arrow points to the water sample,and the MLs(log Kow = 1.63～4.34),PEs(log Kow = 5.43～8.53),QNs that are more easily distributed in the sediments(Log Kow =-1.03～2.50)and TCs(log Kow =-1.30～2.24)The loading arrows point to the sediment samples,indicating that the composition of water and sediment is significantly different,which is mainly related to the distribution behavior of various antibiotics between the two phases.(4)Through PCA-MLR analysis of the pollution sources of antibiotics in the water bodies of the two seasons,it is found that the main sources of antibiotic pollution in the surface waters of the main canal are as follows:1)Pollution from livestock and poultry farms;2)Man-made pollution or direct discharge pollution;3)Soil pollution on agricultural land and 4)Pollution from aquaculture.(5)Select three models of aquatic organisms,green algae,large fleas and fish,and use the risk entropy method to evaluate the ecological risks of antibiotics in the water.The results show that all the detected antibiotics have no ecological risk to green algae,large fleas and fish(RQ <0.01),and the calculation of the joint risk entropy value RQsum found that there is a low ecological risk to large fleas in some sections(such as Xinfeng)(0.01<RQsum<0.1).The risk entropy method was used to evaluate the ecological risk of sediment to the most unfavorable organisms in the sediment,and it was found that SGD may have a potentially low risk in the sediment(0.01<RQ<0.1).The antibiotic health risk assessment results showed that the accumulated RQ value of antibiotics in the surface waters of the main canal of the South-to-North Water Diversion is far below 1,indicating that there is no potential health risk for antibiotics in the main canal of the South-to-North Water Diversion.However,ENR in the southern section of the main canal has a higher risk for infants from 0 to 3 months and should be taken seriously.