洞庭湖流域水环境中典型抗生素污染特征、来源及风险评估

发布时间：2018-08-20 11:23

【摘要】：随着药物及个人护理品(Pharmaceutical and personal care products,PPCPs)污染在全球环境中不断加剧,抗生素作为其中一种分布较广的污染物,因其对人类和生态系统健康构成的严重的潜在威胁已广受环境科学、毒理学及流行病学的关注。我国经济快速发展和人口剧增,每年消耗大量抗生素,已成为世界上最大的抗生素生产和使用国,水环境中的抗生素污染十分严峻。洞庭湖作为重要的水产和畜禽养殖区域,必然会受到一定程度的抗生素污染,但是目前对于洞庭湖抗生素的污染状况、来源及风险等级等鲜有报道。因此,本研究选取洞庭湖国控省控等代表性点位和12种典型抗生素,初步系统地研究了洞庭湖水体、沉积物及鱼体中12种抗生素的赋存特征、来源及风险等级水平,主要结果如下:(1)对现有的水体、沉积物和鱼体样品中的4类12种(磺胺类、磺胺增效剂、喹诺酮类和四环素类)抗生素的提取方法进行了优化,并进行了方法的准确度的检验,方法满足水体、沉积物和鱼体中目标抗生素残留的检测需求;(2)洞庭湖水体中丰水期和枯水期的抗生素检出浓度分别为ND~61.28ng·L-1和ND~8.73ng·L-1,各采样点的抗生素总浓度分别为6.35~135.40ng·L-1和1.06~17.42 ng·L-1,季节差异显著,磺胺类为主要污染物,以南渡、樟树港、扁山、东洞庭湖的抗生素污染程度较高。在空间上,表现为东洞庭湖南洞庭湖西洞庭湖,与水产养殖、畜禽养殖及人口分布等密切相关。水体中抗生素的赋存还受到水体因子叶绿素a(Chla)、高锰酸盐指数(CODMn)、TN等的影响。丰水期沉积物中抗生素的检出浓度ND~5.56 ng·g-1,以磺胺嘧啶、恩诺沙星、金霉素、四环素为主要污染物,空间污染特征与水体基本一致。沉积物中抗生素的赋存与粒径(ps)、沉积物容重等相关。鱼体中抗生素的检出浓度ND~1.06ng·g-1,磺胺嘧啶和恩诺沙星的检出率较高,鲶鱼、鲤鱼和虾等底层生物体内抗生素的含量较高。(3)采用风险熵(RQ)对洞庭湖抗生素的风险等级进行了评价。丰水期和枯水期水体中的主要环境风险因子为环丙沙星、磺胺甲恶唑、恩诺沙星和沙拉沙星,对洞庭湖生态环境具有潜在的风险;枯水期和丰水期抗生素的健康风险值处于5.09×10-8~6.94×10-5·a-1和1.70×10-8~1.28×10-5·a-1之间,喹诺酮类为主要的健康风险因子,风险等级为10-6~10-5数量级,且通过饮用水摄入抗生素对成年人的健康风险高于儿童,南渡、樟树港等地的累积风险较高。沉积物中10种抗生素的RQ处于2.07×10-4-29.87之间,环丙沙星、沙拉沙星为主要的风险因子,东洞庭湖、扁山、马坡湖、坡头、小河嘴、樟树港等地的累积风险较高。洞庭湖鱼体中抗生素的含量远低于最大残留限值(MARL),城市和农村地区通过鱼虾摄入抗生素的风险RDQ分别处于5.85×10-7~5.17×10-4和1.23×10-6~1.09×10-3之间,恩诺沙星和沙拉沙星为主要的健康风险因子,摄食鲶鱼和虾的健康风险较大。(4)通过对洞庭湖周边部分污染源的调查,初步确定了洞庭湖12种抗生素的来源。结果表明:磺胺嘧啶(SDZ)、磺胺甲恶唑(SMX)、磺胺二甲嘧啶(SMZ)、甲氧苄氨嘧啶(TMP)、沙拉沙星(SFLO)和金霉素(CTC)主要来自水产养殖和畜禽养殖源;环丙沙星(CIP)、土霉素(OTC)和氧氟沙星(OFL)主要来自污水处理厂;四环素主要来自于畜禽养殖;恩诺沙星和诺氟沙星主要来自于水产养殖。
[Abstract]:As drug and personal care products (PPCPs) pollution in the global environment continues to intensify, antibiotics as one of the widespread pollutants, because of its serious potential threat to human and ecosystem health has been widely concerned by environmental science, toxicology and epidemiology. With the rapid economic development and rapid population growth, a large number of antibiotics are consumed every year, which has become the largest antibiotic producing and using country in the world. The antibiotic pollution in the aquatic environment is very serious. The distribution, source and risk level of 12 antibiotics in Dongting Lake water, sediments and fishes were studied systematically. The main results are as follows: (1) For existing water, sediments and fishes, 12 kinds of antibiotics were selected as representative sites and 12 kinds of typical antibiotics. The extraction method of 4 kinds and 12 kinds of antibiotics (sulfonamides, sulfonamide synergists, quinolones and tetracyclines) from fish and water samples was optimized, and the accuracy of the method was tested. The method met the detection requirements of target antibiotic residues in water, sediments and fish. (2) Antibiotics in Dongting Lake during flood season and dry season. The detected concentrations were ND~61.28ng.L-1 and ND~8.73ng.L-1, respectively. The total concentrations of antibiotics in each sampling site were 6.35~135.40ng.L-1 and 1.06~17.42 ng.L-1, respectively. The seasonal difference was significant. Sulfonamides were the main pollutants. The antibiotics in Nandu, Zhangshugang, Bianshan and Dongdongting lakes were highly contaminated. Xidongting Lake is closely related to aquaculture, livestock and poultry breeding and population distribution. The occurrence of antibiotics in the water body is also affected by the water body factors such as chlorophyll a (Chla), permanganate index (CODMn), TN and so on. The occurrence of antibiotics in sediments was related to particle size (ps) and bulk density of sediments. The detection concentration of antibiotics in fish was ND~1.06ng g-1, the detection rate of sulfadiazine and enrofloxacin was higher, and the content of antibiotics in catfish, carp and shrimp was higher. (3) Risk Entropy (RQ) The risk grade of antibiotics in Dongting Lake was evaluated. The main environmental risk factors in the high and low water periods were ciprofloxacin, sulfamethoxazole, enrofloxacin and sarafloxacin, which had potential risks to the ecological environment of Dongting Lake. Quinolones were the main health risk factors, and the risk level was 10-6-10-5. The cumulative risk of antibiotics ingested through drinking water was higher in adults than in children, Nandu, Zhangshugang and other places. Salafloxacin was the main risk factor, and the cumulative risk was higher in Dongting Lake, Bianshan, Mapo Lake, Potou, Xiaohezui and Zhangshu Harbor. The antibiotic content in Dongting Lake fish was much lower than the maximum residue limit (MARL), and the risk RDQ of antibiotic intake by fish and shrimp in urban and rural areas was 5.85 *10-7~5.17 *10-4 and 1.23 *10-6~1, respectively. Enrofloxacin and sarafloxacin were the main health risk factors, and catfish and shrimp were the main health risk factors. (4) The sources of 12 antibiotics in Dongting Lake were preliminarily determined by investigating some pollution sources around Dongting Lake. The results showed that sulfadiazine (SDZ), sulfamethoxazole (SMX), sulfamethoxazole (SMZ), trimethoprim (TMZ). Aminopyrimidine (TMP), Sarafloxacin (SFLO) and aureomycin (CTC) are mainly from aquaculture and poultry breeding sources; ciprofloxacin (CIP), oxytetracycline (OTC) and ofloxacin (OFL) are mainly from sewage treatment plants; tetracycline is mainly from livestock and poultry breeding; enrofloxacin and norfloxacin are mainly from aquaculture.
【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52;X824

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