梅江流域四环素类抗生素的空间分布特征与迁移转化规律
文献类型：学位论文
| 作者 | 郭晓 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 陈求稳 |
| 关键词 | 四环素类抗生素，降解产物，养猪场，沉积物，土壤，梅江流域, Tetracyclines, degradation products, piggeries, sediment, soil, catchment |
| 其他题名 | Spatial distribution, transportation and transformation of Tetracyclines antibiotics in Meijiang River catchment |
| 学位专业 | 环境工程 |
| 中文摘要 | 为研究养殖业中四环素类（Tetracyclines, TCs）抗生素的使用对其周边环境及受纳河流生态环境的影响，选取养殖业发达的江西省梅江流域作为研究区域，进行了养猪场规模及用药情况调查。针对其中四个典型的养猪场，调查了养殖废水向环境中迁移的路径，并沿着不同的迁移路径进行排放口水样采集与沟渠沉积物、污水塘沉积物、农田土壤样品采集。同时，对梅江流域范围内的农田土壤以及小溪流、受纳河流的沉积物进行样品采集。利用固相萃取和超高效液相色谱-串联质谱联用提取、测定样品中 11种 TCs浓度。 研究结果显示，养猪场排放口水样中 TCs浓度在g/L级，该处的沉积物中 TCs浓度差别很大。四环素（Tetracycline, TC）及其降解产物的浓度表现为：污水渠沉积物>污水塘沉积物>混合渠沉积物>水田土壤>旱田土壤。土霉素（Oxytetracycline, OTC）及其降解产物的浓度表现为：污水塘沉积物>污水渠沉积物>水田土壤>混合渠沉积物>旱田土壤。OTC类相比于TC类更容易在相对稳定的水体-沉积物系统（如污水塘、水田土壤）中沉积。TCs沿各自迁移路径总体表现出随距离的增加浓度衰减的特征，且开始时衰减迅速，一段距离后衰减趋于缓慢。各养猪场周围的农田土壤、混合渠沉积物均受到TCs污染，多个样品浓度高于土壤中抗生素生态毒害效应的触发值 100g/kg。 流域土壤中 TCs浓度在g/kg级，大部分 TCs及ΣTCs浓度表现为“红壤”中平均浓度最大，“紫色土”次之，“水稻土”中最小的顺序。每个子流域土壤中 TCs浓度与该子流域的养殖密度并无显著的相关关系。与养猪场周边土壤比较发现，二者平均浓度的高低没有表现出规律性。因此，养猪场排出的 TCs大部分都没有进入流域水稻田土壤中。 梅江流域的小溪流和干流沉积物中的 TCs浓度同样在g/kg级，其种类、浓度高低与养猪场水样中一致。各子流域沉积物中 TCs浓度与相应的养殖密度呈正相关关系。大多数 TCs在小溪流沉积物中的最大浓度高于干流，说明TCs是从养猪场进入小溪流，最终汇入干流中。两条支流（会同河、固厚河）的汇入都使得梅江干流沉积物中TC浓度增加，而梅江干流在没有支流汇入的区段从上至下浓度呈衰减态势。TC和 OTC在迁移过程中主要的降解产物分别为差向四环素( Epitetracycline, ETC)、差向土霉素Epioxytetracycline, EOTC），二者同为差向异构化降解产物。降解产物差向脱水四环素（ Epianhydrotetracycline,EATC）等浓度虽然低于其母体，但由于其环境毒性较大，因此存在的生态风险不容忽视。 对比排放口处水样、沉积物样品、流域中土壤样品及小溪流样品可以推断，降雨径流对土壤冲刷带来的 TCs污染并不是小溪流中 TCs的主要来源，通过沟渠直接排放到小溪流的养殖废水可能是主要来源，因此对规模化养殖场养殖废水排放的管理是梅江流域抗生素控制的关键。 |
| 英文摘要 | This study selected the Meijiang River catchment with intensive poultry farming to investigate the impact and environmental risk of tetracyclines (TCs) use on environment and river ecosystem. First, the investigation of piggery scale and drug usage was conducted. Then,four typical piggeries were selected to reveal the transport paths of the livestock wastewater to the environment. The samples of wastewater outlet, sediments in sewer and sewage pond, and farmland soil were collected along each path.Meanwhile, soil and sediment samples of streams were collected in Meijiang River catchment. Finally, the eleven species of TCs in all samples were extracted by solid phase extraction (SPE), and quantified by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The results showed that TCs concentrations of water samples in piggeries were in g/L level, while concentrations in sediment varied greatly in different piggeries.The concentration of TC and its degradation products had a downside: sewer sediment > sewage pond sediment > confluence channel sediment > paddy soil >upland soil. Compared with TC, OTC and its degradation products were apt to deposit in water-sediment system, such as sewage pond or paddy soil, which are relatively stable environment. On different transport paths, the concentration of TCs fell off with distance. The decay started rapidly and slowed down after a certain distance. The research also indicated that farmland soil and sediment in confluence channel were exposed to antibiotics contamination around piggeries. The concentrations in part of the samples were higher than 100 g/kg, which is the triggering threshold of eco-toxicological effect. Based on the results, concentration of TCs in the soil samples were in g/kg level. Average concentration of most TCs and ΣTCs showed the downtrend in “red soil”, “purple soil” and “paddy soils”. There was no significant correlation between TCs concentration of soil and stocking density in the same sub-basin. Comparing with the soil near piggeries from the sub-basin, the average concentrations were irregular. Therefore, most of TCs emitted from piggeries did not transport to the paddy soil in this catchment. Similarly, TCs concentrations of sediments in main stream and tributaries of Meijiang River were in g/kg level, the species, trend of concentration variation of TCs were in accordance with water samples of piggeries. However, there was a positive correlation between TCs concentrations of sediments in sub-basins and the corresponding stocking density. The maximum TCs concentration in the tributaries sediment were higher than that in main stream, indicating that TCs emitted from piggeries ran into the tributaries, and ultimately into the main stream. The inflow from the two tributaries (Huitong stream, Guhou stream) led to the increase of TCs concentrations in sediments in Meijiang River, while the concentration descended from up to down in the segment of main stream without tributary inflow. The main degradation products of TC and OTC were ETC and EOTC respectively, which are the degradation products of epimerization. Although the concentrations of degradation products such as EATC were lower than their parents, the ecological risk was not negligible due to their high toxicity. Contrasting the samples of water and sediment at outlets, catchment soil and stream sediment, it can be inferred that TCs from soil erosion by rainfall was not the main source to tributaries, while sewer wastewater which discharged directly into streams should be the main cause. Therefore, wastewater management on large-scale livestock farming is the key aspect to antibiotics control in Meijiang River Catchment. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34325]  |
| 专题 | 生态环境研究中心_环境水质学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 郭晓. 梅江流域四环素类抗生素的空间分布特征与迁移转化规律[D]. 北京. 中国科学院研究生院. 2015. |
入库方式： OAI收割
来源：生态环境研究中心
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