渭河关中段表层水中抗生素污染特征与风险

Contamination characteristic and ecological risk of antibiotics in surface water of the Weihe Guanzhong section

采用HPLC/MS/MS方法对渭河关中段(咸阳至西安)表层水体中的抗生素进行了检测分析.水样中共检测出5类15种抗生素,检出率在12.5%~100%,检出浓度nd^270.60ng/L.与国内外其他水域相比,渭河关中段表层水体中抗生素检出浓度处于中等水平.检测出的所有抗生素中,磺胺类(包含磺胺增效剂)7种,平均浓度113.68ng/L;大环内酯类3种,平均浓度111.79ng/L;喹诺酮类3种,平均浓度20.55ng/L;林可酰胺类和四环素类各1种,平均浓度分别为23.81和25.66ng/L.磺胺类和大环内酯类为渭河关中段水体中的主要抗生素.磺胺类抗生素的分布呈现上游>中游>下游,大环内酯类呈现中游>下游>上游.来源分析表明禽畜养殖和水产养殖是大环内酯类中游浓度较高的主要原因.而磺胺类残留则在于生活污水和医疗废水排放及禽类养殖.抗生素浓度与渭河同步水污染指标进行相关性分析,水体中ρ(ETM)(红霉素)与ρ(TN)、ρ(CFX)(环丙沙星)和ρ(CTM)(克拉霉素)与ρ(NH3-N)呈显著相关,其他抗生素没有明显的相关关系.通过风险商值RQs对渭河关中段的抗生素残留进行评价,环丙沙星(CFX)、氧氟沙星(OFX)和磺胺甲噁唑(SMX)的RQs≥1,对相应物种表现为高风险;诺氟沙星(NFX)、土霉素(OTC)、罗红霉素(RTM)的0.1≤RQS<1,对相应物种则表现为中等风险.

The antibiotics in surface water sample from Guanzhong section of Weihe River were analyzed by HPLC/MS/MS.Fifteen antibiotics belonging to five categories were detected with the detection rates of12.5%~100%,and the concentrationlevels varied between nd and270.60ng/L.The detected fifteen antibiotics included7sulfonamides(SAs),3macrolides(MLs),3quinolones(QNs),1lincosamides(LIN),and1tetracyclines(TCs).The average concentrations of SAs,MLs,QNs,LIN,andTCs were found to be113.68,111.79,20.55,23.81and25.66ng/L,respectively.Compared with that in other water bodies inChina,antibiotics in Weihe River was in the middle contaminated level.And SAs and MLs were the predominant antibiotics.The distribution of SAs in Weihe River showed upstream>midstream>downstream,while the MLs decreased in the order ofmidstream,downstream and upstream.The source apportionment indicated that livestock farming and aquaculture were mainlyresponsible for the higher MLs residue,while the domestic sewage and medical wastewater were contributed to SAs residue toa certain extent.The correlation analysis between antibiotic residues and water pollution factors showed that there weresignificant correlations between ETM(erythromycin)and total nitrogen(TN),(CFX)(ciprofloxacin)and(CTM)(clarithromycin)with ammonia nitrogen(NH3-N).In addition,risk quotient(RQ)indicated that CFX,OFX and SMX posedhigher risk to corresponding species,while NFX,OTC,and RTM presented a moderate risk.