【作者】 谭超；

【导师】 颜智勇；

【作者基本信息】 湖南农业大学 ， 环境工程， 2017， 硕士

【摘要】 随着我国养殖业迅速发展,我国成为了世界上的养殖大国。为了促进畜禽的生长、保证畜禽的健康,许多畜禽养殖场将抗生素恩诺沙星作为饲料添加剂添加到畜禽饲料中,造成恩诺沙星一部分残留在畜禽体内,一部分随畜禽尿液和粪便以原型或者代谢产物的形式排出体外,进入畜禽养殖废水处理系统。本试验研究了畜禽养殖废水中的恩诺沙星在UASB反应器中的迁移与降解,探讨了恩诺沙星对UASB反应器去除畜禽养殖废水中COD的影响。得出以下结论:(1)恩诺沙星在避光的水环境中基本不发生水解,且在10℃~40℃的温度条件下或者pH值在3~11时,恩诺沙星在避光水环境中依然稳定存在,说明温度和pH值都不能加快或者影响恩诺沙星在避光水环境中的自身水解。(2)失活厌氧颗粒污泥吸附初始浓度为10~50 mg/L的恩诺沙星均在6h内基本达到吸附平衡,去除率为95%~98%,并且在此浓度范围内吸附平衡时间与恩诺沙星的初始浓度无关。当废水的pH值为3~9时,灭活厌氧颗粒污泥对恩诺沙星的吸附效果保持在93.6~97.4%之间,但当pH值大于9时,灭活厌氧颗粒污泥对恩诺沙星的吸附效果降低,吸附率小于60%。在20℃~40℃的温度条件下,Langmuir吸附方程能更好的拟合失活厌氧颗粒污泥对恩诺沙星的吸附规律,相关系数R_L2>0.99。在20℃、30℃、40℃的情况下,Langmuir常数中的理论最大吸附量q_m分别为1.4019 mg/g、1.36246 mg/g、1.31904mg/g,说明失活厌氧颗粒污泥对恩诺沙星的吸附性能会随温度的升高而降低。(3)活性厌氧颗粒污泥降解初始浓度为10~50 mg/L恩诺沙星在8h后达到平衡,降解率为0.4%~2.9%,且降解的平衡时间都与恩诺沙星的初始浓度无关,降解率随浓度的升高而升高。当废水中的pH为中性条件时,厌氧微生物对水中恩诺沙星的降解效果最好,降解率为3.3%左右,弱酸性和弱碱性的条件都不利于厌氧微生物对恩诺沙星的降解作用。当温度分别为10℃、20℃、30℃、40℃时,厌氧微生物对水中恩诺沙星的降解率分别为2.36%、2.58%、2.74%、2.80%,降解率随着温度的升高而少量升高。(4)在温度为35℃、pH值为7的条件下,当浓度为10~800mg/L的恩诺沙星的畜禽养殖废水在进入UASB反应器12h后,其水解、吸附和降解占总去除率的比例分别为0%、96~98%、2~4%。活性厌氧颗粒污泥吸附了一定量的恩诺沙星后,厌氧颗粒污泥对畜禽废水中COD的去除率将会下降,当厌氧颗粒污泥对恩诺沙星的吸附量小于0.948mg/g时,厌氧微生物能正常进行生命活动,其COD去除率保持正常,维持在70%~80%,当吸附量超过0.948mg/g,厌氧颗粒污泥中的厌氧微生物的对COD的去除效果下降,随着吸附量从0.948mg/g增加至最大吸附量1.178mg/g左右,UASB反应器对畜禽废水COD的去除率越来越低,最后仅剩30%左右。更多还原

【Abstract】 The aquaculture industry of china is developing rapidly;China has become the one of the biggest breeding country in the world.In order to promote the health growth of livestock,many livestock and poultry farms add enrofloxacin as a feed additive to livestock feed.Resulting in a part of Enrofloxacin residues in livestock and poultry body,another part of enrofloxacin was eliminated from the body with the urine and feces of livestock;and in the form of prototypes or metabolites,and thendischarged into livestock and poultry farming wastewater treatment system.In this experiment,the migration and degradation of enrofloxacin in anaerobic UASB reactor and the effect of enrofloxacin on the removal of COD in livestock wastewater from anaerobic UASB reactor were studied.Concluded as follow:(1)Enrofloxacin in the dark water environment does not hydrolysis,and in the 10℃~40℃temperature conditions or pH range of 3 to 11,enrofloxacin in the dark water environment is still stable,indicating that the temperature and pH cannot speed up or affect enrofloxacin in the dark water environment of self-hydrolysis.(2)The adsorption of enrofloxacin at the initial concentration of 10~50 mg/L in inactivated anaerobic granular sludge has reached the adsorption equilibrium within 6 hours.And the removal rate was 95%to 98%,the adsorption equilibrium time is independent of the initial concentration of enrofloxacin within this concentration range.When the pH value of the wastewater is within 3~9,the adsorption rate of anaerobic granular sludge on enrofloxacin is kept between 93.6~97.4%,but When the pH value exceeds 9,the adsorption effect of anaerobic granular sludge on enrofloxacin is less than 60%.The Langmuir adsorption equation can fit the adsorption of anaerobic granular sludge to enrofloxacin better at the temperature of 20℃~40℃.The correlation coefficient is R_L2>0.99.The theoretical maximum adsorption capacity(qm)in the Langmuir constant is 1.4019 mg/g,1.36246mg/g,1.31904mg/g under the temperature of 20℃~40℃,which indicates that the adsorption performance of inactivated anaerobic granular sludge to enrofloxacin will decrease with increasing temperature.(3)The degradation of enrofloxacin on the initial concentration of 10~50 mg/L of anaerobic granular sludge for 8 h,anaerobic microorganisms had no degradation effect on enrofloxacin in water,and The degradation rate was between 0.4%and 2.9%;At the initial concentration of 10~50mg/L,the degradation time was independent of the initial concentration of enrofloxacin,and the degradation rate increased with the increase of the concentration.When the pH of water is neutral,the anaerobic microorganisms have the best degradation effect on enrofloxacin,the degradation rate is about 3.3%,and the conditions of the acid and the alkali are not conducive to the anaerobic microorganisms.When the temperature was 10℃,20℃,30℃and 40℃,respectively.The degradation rate of enrofloxacin in water was different 2.36%,2.58%,2.74%,2.80%.The degradation rate of enrofloxacin in anaerobic microorganisms increased with the increase of temperature.(4)Under the conditions of temperature of 35℃,pH value of 7,when the concentration of 10~800mg/L Enrofloxacin livestock and poultry wastewater into the UASB reactor after 12h.The ratio of hydrolysis,adsorption and degradation of livestock and poultry wastewater containing enrofloxacin whose concentration of 10~800mg/L was 0%,96~98%and 2~4%,respectively,after entering the anaerobic UASB reactor..The removal rate of COD in the wastewater of livestock and poultry wastewater will decrease when anaerobic granular sludge adsorbs a certain amount of enrofloxacin.When the adsorption capacity of anaerobic granular sludge to enrofloxacin is less than 0.948 mg/g,the anaerobic microorganisms in the anaerobic granular sludge can normally carry out life activities.The COD removal rate is normal and maintained at 70%~80%.Once the anaerobic granular sludge has an adsorption capacity of enrofloxacin over 0.948 mg/g,the anaerobic microorganisms in anaerobic granular sludge have a reduced effect on COD removal.With the increase of adsorption capacity from 0.948 mg/g to the maximum adsorption capacity of1.178 mg/g,the removal rate of COD in anaerobic UASB reactor is getting worse,and finally only about 30%has been left.更多还原