| In the national “14th Five-Year Plan” proposal,Antibiotic is considered to be a new key pollutant.Antibiotic is not only used in the treatment of various human diseases,but also widely used in poultry and livestock breeding and aquaculture.The abuse of antibiotics has led to the emergence of a large number of antibiotic resistance bacteria(ARB)in the environment,and the root cause of ARB resistance to antibiotics is due to antibiotic resistance genes(ARGs).Wastewater treatment plants,as a common wastewater treatment facility,cannot remove the antibiotics and ARGs completely,and the treated wastewater was directly discharged into nature,makes the microorganisms in the environment gradually develop antibiotic resistance,which in turn harms people’s health.Therefore,it is necessary for us to study the distribution and transformation of antibiotics and ARGs in the wastewater treatment plants.This study took a wastewater treatment plant in Nanjing as the research object.Samples were collected in November 2019 and July 2020.Explored the content levels and changing laws of antibiotics,ARGs and microbial communities,analyzed the relationship between the three.The main research results are as follows:(1)In the wastewater treatment plant inflow,The types of antibiotics in winter were detected 5 categories and 10 species,the concentration range is 1.66-592.68ng/L.The types of antibiotics in summer were detected 4 categories and 21 species,the concentration range is 2.78-405.60 ng/L.In winter,the wastewater treatment plant can be detected three kinds of ARGs: sul 1,sul 3,cml A,and the removal levels were1.81,0.38 and 1.68;In summer,the wastewater treatment plant can be detected eight kinds of ARGs: sul 1,sul 3,tet A,tet B,cml A,qnr B,erm B,erm 36,while the removal levels were 1.27,1.47,0.83,0.81,1.97,0.02,-0.16 and 0.35.(2)In winter,the types of antibiotics in the receiving water(4 categories and 8species)are significantly less than those in summer(4 categories and 22 species).The total concentration of antibiotics in winter ranges from 20.28 to 194.00 ng/L.The total concentration of antibiotics in summer ranges from 559.08-2163.7 ng/L.In the receiving water,the ranges of sul 1,sul 3,cml A in winter were 6.13-6.84,5.41-6.07,5.14-6.09;and the the magnitude ranges of sul 1,sul 3,tet A,tet B,cml A,qnr B,erm B,erm 36 in summer were 6.79-7.56,5.10-6.26,7.35-7.73,5.65-7.13,6.81-8.02,5.99-7.14,6.06-6.84,6.14-6.78.(3)In both winter and summer,Proteobacteria are the most dominant bacterial phyla in wastewater treatment plants and receiving water.According to the correlation analysis,some antibiotics and ARGs in the wastewater treatment plant and its receiving water has a significant impact on the abundance of the phylum. |
