污染场地中氟喹诺酮类抗生素的风险评价、污染行为及控制研究

发布时间：2018-04-12 17:25

本文选题：氟喹诺酮 + 吸附　；参考：《东华大学》2017年硕士论文

【摘要】：氟喹诺酮类抗生素是畜牧养殖业中广泛使用的广谱性抗菌剂。抗生素施用于动物后,60-90%以抗生素原药或代谢物的形式经动物排泄物排出,对地表水、土壤、沉积物、地下水等造成污染,影响动物、植物和微生物的正常生命活动,并通过食物链最终影响人类的健康。抗生素的抗性基因属于新型环境污染物,其危害风险较抗生素本身更严重更复杂。本文通过对集约化养殖场污染场地中氟喹诺酮类抗生素的调查、污染途径分析与控制实验,进行了抗生素及其抗性基因的风险评价,为控制抗生素及抗性基因的污染提供科学依据。开展环境中氟喹诺酮类抗生素的生态风险、污染行为及控制技术的研究具有重要的意义。本文研究结论如下:(1)利用物种敏感性评价方法得到的诺氟沙星、环丙沙星、恩诺沙星的在地表水中的预计无影响浓度(PNEC)分别为ρ(诺氟沙星)2.66μg/L、ρ(环丙沙星)9.92μg/L、ρ(恩诺沙星)5.11μg/L;根据物种敏感性分布评价结果利用风险熵值法RQ=PEC/PNEC评价中国地表水体的氟喹诺酮类抗生素污染风险。结果表明:除黄河、渤海湾、大辽河地表水中诺氟沙星的风险为低风险以外,地表水中氟喹诺酮的污染分布无风险。地表水急性水质基准CMC分别为:ρ(诺氟沙星)5.39μg/L、ρ(环丙沙星)20.10μg/L,ρ(恩诺沙星)11.16μg/L,慢性水质标准ccc分别为ρ(诺氟沙星)2.66μg/l、ρ(环丙沙星)9.92μg/l,ρ(恩诺沙星)5.51μg/l,以期为建立抗生素地表水环境质量标准提供参考。(2)利用评价因子法得到的诺氟沙星、环丙沙星、恩诺沙星在土壤环境中的pnec分别为11.30μg/kg、1.13μg/kg、45.00μg/kg。根据评价因子法结果利用风险熵值rq=pec/pnec评价了山东菜地、东莞菜地、福建养殖场周边土壤环丙沙星均表现为高风险,应该重点监控。山东菜地、东莞菜地诺氟沙星为中等风险,恩诺沙星为低风险。(3)在综合分析抗性基因的产生过程、传播途径、基因降解及抗性细菌的耐药程度等基础上,提出“渐变-累积-突变”理论,建立了抗性基因的风险评价体系。通过危害识别、暴露评估、风险表征3个步骤,其中暴露评估将综合风险分为4个指数来分别评价:抗性指数、传播指数、污染指数、降解指数。通过分别对每个指数进行评分计算,将分值乘以权重后相加得到综合风险,对风险进行分级,得到相对风险等级1-5级。(4)诺氟沙星、环丙沙星、恩诺沙星在三种不同场地介质中的吸附动力学均符合准二级动力学方程,其中在有机肥的影响下,三种氟喹诺酮类抗生素的吸附速率加快。其中环丙沙星更容易被吸附,三种氟喹诺酮类抗生素的迁移能力cipnorenr。在三种场地介质中诺氟沙星、环丙沙星、恩诺沙星的吸附热力学符合freundlich模型,属于物理吸附。三种介质中的吸附行为差异明显。其土壤kf值分别为:47.4679、47.2607、33.9860;土壤+粪便kf值分别为:81.4329、90.1779、46.2594;土壤+有机肥kf值分别为:128.0855、133.5365、64.0914。(5)通过土柱淋溶实验,在40天试验时间中,土柱内抗生素未见明显淋出,且三种初始浓度不同污染溶液对土柱中抗生素淋出情况并无影响,三种不同氟喹诺酮类抗生素的淋出行为相似。原因在于诺氟沙星、环丙沙星、恩诺沙星的吸附系数大,土壤黏度较大,一部分的抗生素被土壤吸附,三种抗生素的半衰期较短,一部分自身降解,由于土壤环境中存在微生物,不排除被微生物降解的可能性。土柱实验结果表明:当抗生素未经处理直接排放到土壤中时,在短时间内会在土壤中积累,由于抗生素自身的水解等作用且与土壤结合,不会导致地下水的污染,但是长时间低剂量的暴露会诱导土壤中抗性基因的产生,从而形成抗性细菌,当抗性基因通过水平扩散等作用实现在不同种微生物之间的传播,诱导超级细菌的产生。因此需要预防抗生素进入土壤环境。(6)通过木屑、稻谷壳、稻谷炭、颗粒活性炭等吸附实验,表明活性炭对诺氟沙星、环丙沙星、恩诺沙星吸附效果最好,去除率均达到90%以上。活性炭对三种氟喹诺酮类抗生素的吸附符合准二级吸附动力学,反应时间60min左右,三种氟喹诺酮类抗生素基本达到吸附平衡,其中活性炭对恩诺沙星的单位吸附平衡量最大,可达到2000mg/kg;活性炭对三种氟喹诺酮类抗生素的吸附符合freundlich吸附模型,属于物理吸附过程,kf值分别为诺氟沙星1148.9735、环丙沙星1115.8351、恩诺沙星1200.3835。通过超声再生活性炭实验表明,在超声进行到25 min时超声再生效率达到最大,诺氟沙星、环丙沙星、恩诺沙星分别为68.5%、68.0%、69.9%;当温度为35℃时超声再生活性炭的再生效率最高,诺氟沙星、环丙沙星、恩诺沙星分别为73.1%、72.7%、73.6%;当超声的频率为40 KHz时,超声对活性炭的再生效率最高,诺氟沙星、环丙沙星、恩诺沙星分别为76.5%、75.4%、79.0%。
[Abstract]:Fluoroquinolones are broad-spectrum antibiotics widely used in animal husbandry. Antibiotics antibacterial agent applied to animal, 60-90% to antibiotics or metabolites in the form of the original animal excrement discharged to surface water, soil, sediment, groundwater pollution, affect the normal life activities of animals, plants and microorganisms, and through the food chain the final impact on human health. The antibiotic resistance gene is a new type of environmental pollutants, the risk is more serious and more complex. The antibiotic itself through investigation of intensive farms contaminated sites of fluorine in quinolone antibiotics, pollution analysis and control experiment for the risk assessment and its antibiotic resistance genes, to provide scientific basis for for the control of antibiotic resistance genes and pollution. To carry out the ecological risk of fluoroquinolone antibiotics in the environment, pollution behavior and control technology It has important meaning to research. The conclusions of this study are as follows: (1) ciprofloxacin using species sensitivity evaluation method of norfloxacin, enrofloxacin, is expected in the surface water had no effect concentration (PNEC) respectively, P (norfloxacin) 2.66 g/L, P (Huan Bingsha) 9.92 g/L, P (enrofloxacin) 5.11 g/L; evaluation of fluoroquinolone antibiotics pollution risk Chinese surface water according to the evaluation results using species sensitivity distribution risk entropy method RQ=PEC/PNEC. The results showed that: in addition to the Yellow River, the Gulf of Bohai, the risk in surface water norfloxacin as low risk, fluoroquinolones in surface water pollution distribution without the risk of surface water quality criteria for acute CMC. Respectively: P (norfloxacin) 5.39 g/L, P (ciprofloxacin) 20.10 g/L, P (enrofloxacin) 11.16 g/L, chronic water quality standard CCC were p (norfloxacin) 2.66 g/l, P (ciprofloxacin) 9.92 g/ L, P (enrofloxacin) 5.51 g/l, in order to provide reference for the establishment of environmental quality standards for surface water antibiotics. (2) obtained by factor analysis of ciprofloxacin, norfloxacin, enrofloxacin PNEC in soil were 11.30 g/kg, 1.13 g/kg, 45 g/kg. according to the factor analysis results the use of rq=pec/pnec to evaluate the risk entropy of Shandong vegetable, vegetable farms in Fujian of Dongguan, the surrounding soil ciprofloxacin showed high risk, should focus on monitoring. Shandong Dongguan vegetable, vegetable norfloxacin enrofloxacin for moderate risk, low risk. (3) in the transmission process, a comprehensive analysis of the resistance gene, gene degradation and resistance of bacteria the degree of resistance on the basis of "gradual accumulation catastrophe" theory, establish a risk assessment system. The resistance gene by hazard identification, exposure assessment and risk characterization of 3 steps, which exposed. The comprehensive evaluation risk is divided into 4 index were evaluated: resistance index, propagation index, pollution index, degradation index. Through each index score calculation, the weight multiplied by the sum of scores after the comprehensive risk, classification of risk, relative risk grade 1-5. (4) norfloxacin, ciprofloxacin. The adsorption kinetics in three different venues in the medium of enrofloxacin were pseudo two order kinetics equation, in which the effect of organic fertilizer, the adsorption rate of three kinds of fluoroquinolone antibiotics ciprofloxacin accelerated. Which absorbed more easily, three kinds of fluoroquinolone antibiotics and migration ability of cipnorenr. in three kinds of norfloxacin, ciprofloxacin in ground medium. Thermodynamics of adsorption of enrofloxacin in line with the Freundlich model, the difference is physical adsorption. The adsorption behavior of three kinds of medium is obvious. The soil KF value respectively: 47.4679,47.2 607,33.9860; soil and fecal KF values were: 81.4329,90.1779,46.2594; soil organic fertilizer + KF = 128.0855133.5365,64.0914. (5) by soil column leaching experiment, on the 40 day test time, soil column leaching and no antibiotics, three kinds of different initial concentrations of antibiotics pollution solution in the soil column leaching was no effects of three kinds of Fluoroquinolone antibiotics leaching behavior similar. Because of norfloxacin, ciprofloxacin, enrofloxacin adsorption coefficient, soil viscosity, a part of the antibiotics adsorption by soil, three kinds of antibiotics has a short half-life, a part of its degradation, due to the presence of microorganisms in the soil environment, do not rule out by microbial degradation the possibility of soil column experiment results show that when the direct discharge of untreated antibiotics into the soil, will accumulate in the soil in a short period of time, due to the antibiotics themselves The hydrolysis effects and combined with the soil, will not cause the pollution of groundwater, but long time low dose exposure can induce the soil resistance gene, resulting in the formation of resistant bacteria, when the resistance gene in communication between different kinds of microorganisms by horizontal diffusion effects induced by super bacteria. So we must prevent antibiotics into the soil the environment. (6) by sawdust, rice husk, rice carbon, granular activated carbon, adsorption experiments showed that the activated carbon of norfloxacin, ciprofloxacin and enrofloxacin had the best effect on adsorption, the removal rate reached more than 90%. The adsorption of three kinds of fluoroquinolones with quasi two stage activated carbon adsorption kinetics, the reaction time is about 60min. Three kinds of fluoroquinolones reached equilibrium, in which the unit of activated carbon on the adsorption equilibrium of the largest amount of enrofloxacin, can reach 2000mg to three /kg; activated carbon Adsorption of fluoroquinolones with Freundlich adsorption model belongs to physical adsorption process, the KF values were 1148.9735 and 1115.8351 of norfloxacin, ciprofloxacin and enrofloxacin 1200.3835. by ultrasound showed that the activated carbon regeneration experiment in ultrasound at 25 min ultrasonic regeneration efficiency reaches the maximum, norfloxacin, ciprofloxacin and enrofloxacin were 68.5%, 68%, 69.9%; when the temperature is 35 DEG C when ultrasonic regeneration of activated carbon regeneration efficiency, norfloxacin, ciprofloxacin and enrofloxacin were 73.1%, 72.7%, 73.6%; when the ultrasonic frequency is 40 KHz, ultrasonic on activated carbon regeneration efficiency highest, norfloxacin, ciprofloxacin and enrofloxacin were 76.5%, 75.4%, 79.0%.

【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X713;X82

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