东江上游典型抗生素污染特征及生态风险评价

摘要

Antibiotics were detected in water in recent years, but there was little research on the contamination of antibiotics in the drinking water source. This article investigated the contamination characteristics and ecological risk of typical antibiotics in the upper reaches of the Dongjiang River by SPE (Solid Phase Extraction) and LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry). The content level of the six typical antibiotics (sulfonamides, quinolones,β-lactams, macrolides, tetracyclines, lincosamides) was measured at temporal and spatial scope and ecological risk was assessed by RQ (risk quotient) method. The results showed that most of the detection rate of the 12 antibiotics detected in the upper reaches of the Dongjiang River was high, the overall mass concentration ranges were from nd (not detected)~69.9 ng·L-1 and the top three of the highest average mass concentration were tetracycline (32.24 ng·L-1), norfloxacin (27.84 ng·L-1), ofloxacin (24.54 ng·L-1). In the spatial and temporal distribution, the concentration of antibiotics in the upper reaches of the Dongjiang River was mainly affected by non-point source pollution caused by surface runoff, and some areas were affected by tributary influx. Compared with the content of the antibiotics in domestic rivers, the concentration of antibiotics was in the medium level or slightly lower in general and the concentration of tetracycline and tylosin is relatively high. The correlation analysis between antibiotics and routine indexes indicated that the concentration of most antibiotics was positively correlated with organic pollution, and the level of antibiotics was influenced by environmental factors. The result of the ecological risk assessment by RQ method indicated that norfloxacin and Penicillin G have high risk. Sulfadiazine, tylosin, doxycycline, oxytetracycline and lincomycin had medium risk and the upper reaches of the Dongjiang River had some ecological risk as a whole.%近年来水体中不断被检出抗生素，但在饮用水源地中对抗生素的污染状况研究很少。为了探讨东江上游水体中典型抗生素的污染特征及潜在的生态风险，利用固相萃取（SPE）及液相色谱-串联质谱（LC-MS/MS）技术，分别在时空尺度上测定了6类典型抗生素（磺胺类、喹诺酮类、β-内酰胺类、大环内酯类、四环素类、林可霉素类）的含量水平，并采用风险商法对其进行生态风险评价。结果表明：东江上游水体中被检测出的12种抗生素中，绝大部分检出率都较高，整体质量浓度范围在nd（未检出）~69.9 ng·L-1，其中平均质量浓度最高的3种抗生素分别是四环素（32.24 ng·L-1）、诺氟沙星（27.84 ng·L-1）、氧氟沙星（24.54 ng·L-1）。在时空分布上，东江上游干流抗生素的浓度主要受地表径流产生的面源污染影响，部分地区受到支流汇入的影响较大。与国内河流中抗生素的含量水平相比，东江上游抗生素浓度整体处于中等偏低水平，其中四环素和泰乐菌素相对偏高。抗生素与常规指标的相关性分析表明，抗生素大部分种类的浓度与有机物污染呈正相关，并且其含量水平受到环境因素的制约和影响。风险商法得出的生态风险评价结果表明，诺氟沙星和青霉素 G 存在较高风险，磺胺嘧啶、泰乐菌素、强力霉素、氧四环素和林可霉素达到了中等风险，整体上存在一定的生态风险。