Occurrence Characteristics Of Typical Antibiotics In Surface Water Of Luoma Lake And Adsorption Behavior On Sediments

Luoma Lake,as an important drinking water source in Northern Jiangsu Province,has been increasingly polluted in recent years.In this study,44 sampling sites were set up in the surface water of Luoma Lake and its rivers,39 kinds of antibiotics were tested,and their ecological risk and health risk were assessed.The adsorption characteristics of three quinolones antibiotics（QNs）,norfloxacin（NOR）,ciprofloxacin（CIP）and ofloxacin（OFL）,on the sediments of Luoma Lake were studied.The conclusions are as follows:（1）Three kinds of QNs and eight kinds of sulfa antibiotics（SAs）were detected in Luoma Lake and its rivers.The highest detection concentration of OFL in QNs was 22.79ng/L,the detection rate of SAs entering the lake is significantly higher than that in the lake.The detection rate of chlortetracycline（CTE）in tetracycline antibiotics（TCs）was 100%,and the highest detection concentration was 330.24ng/L.The highest detection concentration of roxithromycin（ROX）in macrolides antibiotics（MLs）was 566.78ng/L,which was the highest in this study.The highest concentrations of clindamycin（CLI）and lincomycin（LIN）were 216.38ng/L and81.34ng/L,respectively.The concentration range of all sampling sites was34.91ng/L-825.93ng/L,and there were significant differences among different sampling sites.On the whole,the concentration of antibiotics in the western part of the lake was higher than that in the eastern part,and the content of antibiotics in the lake<Baimahe,Yihe,Laoyi River,Liutang River<Bulao River,Zhongyun River and Fangting River,indicating that the antibiotic pollution in the rivers entering the lake through Xuzhou City was relatively serious.（2）Antibiotics in Luoma Lake and the rivers entering the lake were no ecological risk and low ecological risk,accounting for 92.58%.QNs in the detected sampling sites were all at a medium level or above,and CIP and OFL were at high ecological risk in the relatively polluted sections of Bulao River,Zhongyun River and Fangting river.The Proportion of high risk antibiotics of Baima River,Yihe River,Laoyi River and Liutang River（5.31%）<in Lake（6.19%）<Bulao River,Zhongyun River and Fangting River（11.97%）.（3）There was no health risk in Luoma Lake,and the proportion of health risk in the rivers entering the lake was 5.42%.Only two antibiotics,ROX and CTE had health risks.CTE was a major health risk for infants aged 0-3 months,but ROX was a health risk at all ages of the Bulao River,Zhongyun River and the Fangting reach.（4）The adsorption of three QNs on Luoma Lake Sediment reached equilibrium in 8h,and the fitting effect of quasi second-order kinetic equation was the best.Langmuir curve could better describe the isothermal adsorption of three QNs.The adsorption capacity of three QNs was the highest at pH=5,but decreased with the increase of pH.The higher the soil water ratio,the lower the adsorption capacity of three QNs.Na⁺had no obvious inhibition on adsorption,Ca²⁺and Mg²⁺had obvious inhibition on adsorption,and Al³⁺promoted adsorption.QNs may have many effects on the sediments of Luoma Lake,such as ion exchange,complexation and flocculation.There are 31 figures,31 tables and 118 references in this paper.