The Removal Of Tetracycline Antibiotics And Effect On Resistance Genes By Electrode SBR

In recent years,antibiotics have been widely used in the treatment of human and mammalian diseases,and most of the antibiotics can not be absorbed by human and animal metabolism,resulting in a large number of antibiotics into the sewage.Sewage treatment plant as antibiotics into the environment of the last barrier,the existing process can not effectively remove the antibiotics in the sewage,but also lead to the expansion and metastasis of antibiotic resistance gene.Based on the Sequencing Batch Reactor,the bioelectrochemical system(BES)was constructed by applying an electric field.The results showed that the removal of tetracycline antibiotics and antibiotic resistance genes by BES was as follows:(1)Eight kinds of tetracycline antibiotics were established and evaluated.The detection rate of the tetracycline antibiotics was 77.4%～113.3%,the relative standard deviation was less than 10%,the linear correlation coefficient of the standard curve was more than 0.998,and the detection limit was 1.46～12.50 μg·L-1.(2)When the reaction period is 12 h,the voltage is 1.5 V,the influent COD concentration is 1000 mg·L-1,the concentration of each tetracycline antibiotic is 0.5 mg·L-1 and the pH is 7.0,the optimal condition of tetracycline antibiotic removal is reached,the average removal rate was 92.3%.(3)The adsorption and electrolytic effects of tetracycline antibiotics in BES were investigated.The results showed that the removal rate of tetracycline antibiotics was 41.9%under the same conditions,and the removal rate was 41.6%,and the removal rate of tetracycline was only 48%.The electrolysis process conforms to the first order reaction kinetics model.The degradation products and degradation process of tigecycline were analyzed.(4)The microbial communities in SBR and BES were analyzed by high-throughput sequencing.The community structure map showed that the actinomycetes,myostereomes and Bacteroides were the main dominant species.The fungal mesocysts were the only dominant species.Different conditions have different effects on microbial communities.BES has less bacterial diversity than SBR under the same conditions.(5)The detection rate of eight ARGs in the inoculated sludge was 100%and the concentration range was 103.73～105.74 copies·mL-1.With the operation of the process,the concentrations of tetA,tetC,tetG,tetM and tetX were significantly increased,while the concentrations of tetO,tetQ and tetW were significantly decreased.Under the same conditions,the average concentration of tetA,tetC,tetG,tetM and tetX in BES was lower than that of SBR.