厌氧消化工艺处理含土霉素污水厂污泥研究

发布时间：2018-03-22 15:47

本文选题：厌氧消化　切入点：土霉素　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国每年土霉素生产量达10000吨以上,占世界总产量的65%,而生产过程中会产生高浓度的土霉素废水。另外,它作为廉价兽药广泛使用于牲畜和水产养殖。80%以上的土霉素会以原药形式随排泄物排放至体外,最终进入养殖废水。因此每年有大量含土霉素的生产废水和养殖废水需污水厂处理。而在处理过程中,污泥吸附是去除污水中土霉素最主要的途径。污水中绝大多数土霉素通过吸附形式转移至污泥,从而使得每年产生大量含土霉素污泥。而目前国内多数污泥最终的处置办法是填埋,若不对含土霉素的污泥进行适当处理,将对土壤环境造成严重危害。而厌氧消化是当前处理污泥的主要工艺,因此研究厌氧消化工艺处理含土霉素的污水厂污泥具有重要意义。本课题采用静态批次实验和动态半连续流完全混合反应器相结合的方式,以含有不同浓度土霉素的污泥为研究对象,考察了中温厌氧消化和高温厌氧预处理对土霉素的降解作用及受土霉素抑制的情况。并研究了土霉素在污泥厌氧消化中的降解途径,以及微生物群落结构在不同浓度土霉素压迫下的演变规律。通过静态批次实验表明,土霉素浓度达到5mg/L时即对厌氧消化的沼气产量有明显抑制,削减量达17.24%,当达到100mg/L时,对沼气产量的削减高达58.43%。另外,通过灭菌组和未灭菌组的批次实验得出,运行15天后,有23.92%的土霉素通过水解途径而降解,而通过生物降解途径降解的土霉素达到37.82%。总体降解率为61.74%。说明生物降解是土霉素在污泥消化中的主要降解途径。通过半连续流单相中温厌氧反应器的运行分析得出,进泥中土霉素含量为5mg/L、30mg/L、100mg/L时,对沼气产量的削减分别为17.24%、21.00%、26.36%,而土霉素的降解率分别为56.06%~63.46%、48.05%、63.26%。在前端采用高温厌氧预处理后,上述土霉素浓度下,对沼气产量的削减分别为5.29%、5.84%、9.22%,对土霉素总体降解率分别达到了81.67%~87.04%、83.96%、86.19%。表明高温厌氧预处理能有效强化对土霉素的去除并减轻其对沼气产量的抑制作用。采用末端限制性片段长度多态性分析(T_RFLP)技术对微生物群落的检测结果表明,随着土霉素的投加及浓度的增加,细菌和古细菌的优势种群在不断发生演替,群落结构在不断发生变化。这反映了微生物为了应对更高浓度土霉素而调整自身群落结构,以便能更好地适应环境的变化。综上所述,常规中温厌氧消化工艺对土霉素具有一定的去除作用,配合高温厌氧预处理能将土霉素去除率提高至85%左右,有效地削减土霉素排放量。该工艺成熟可靠,具有一定的工程实际意义。
[Abstract]:The annual production of oxytetracycline in China reaches more than 10000 tons, accounting for 65% of the world's total output. In addition, high concentrations of oxytetracycline wastewater are produced during the production process. It is widely used as a cheap veterinary drug in livestock and aquaculture. More than 80% of oxytetracycline is released into the body with excreta in the form of raw drugs. So every year a lot of production and culture wastewater containing oxytetracycline need to be treated by sewage treatment plant, and in the process of treatment, Sludge adsorption is the most important way to remove oxytetracycline from sewage. Therefore, a large amount of oxytetracycline sludge is produced every year. At present, the final disposal method of most sludge in China is landfill. If the sludge containing oxytetracycline is not properly treated, Anaerobic digestion is the main process for sludge treatment. Therefore, it is of great significance to study the anaerobic digestion process to treat the sludge of wastewater treatment plant containing oxytetracycline. In this paper, the static batch experiment and the dynamic semi-continuous flow complete mixing reactor are adopted. The degradation of oxytetracycline and its inhibition by oxytetracycline in sludge containing different concentrations of oxytetracycline were investigated, and the degradation pathway of oxytetracycline in anaerobic digestion of sludge was studied. And the evolution of microbial community structure under the pressure of different concentrations of oxytetracycline. The static batch experiments showed that oxytetracycline reached 5mg/L concentration, which significantly inhibited the anaerobic digested biogas production, and reduced by 17.24%, and when reached 100mg/L, the biogas production of anaerobic digestion was significantly inhibited when the concentration of oxytetracycline reached to 100mg/L. In addition, after 15 days of operation, 23.92% of oxytetracycline was degraded by hydrolysis. However, the biodegradation rate of oxytetracycline reached 37.82% and the total degradation rate was 61.74. The results showed that biodegradation was the main degradation pathway of oxytetracycline in sludge digestion. When the content of oxytetracycline in the mud is 5 mg / L 30 mg / L and 100 mg / L, the reduction of biogas production is 17.240.21.00 and 26.36, respectively, and the degradation rate of oxytetracycline is 56.06 / L 63.46 / L and 48.05 / 63.26.After the pretreatment of the front end with high temperature anaerobic treatment, the above mentioned oxytetracycline concentration is below the concentration of oxytetracycline. The total degradation rate of oxytetracycline reached 81.67% and 83.966.19% respectively. The results showed that high temperature anaerobic pretreatment could effectively strengthen the removal of oxytetracycline and reduce its inhibitory effect on biogas production. Fragment length Polymorphism (SLP) technique was used to detect microbial communities. With the addition and concentration of oxytetracycline, the dominant populations of bacteria and Archaea continue to evolve and the community structure is constantly changing, which reflects that the microbes adjust their community structure in response to higher concentrations of oxytetracycline. In order to adapt to the change of environment better. To sum up, the conventional medium temperature anaerobic digestion process can remove oxytetracycline to a certain extent, and the removal rate of oxytetracycline can be increased to about 85% with the combination of high temperature anaerobic pretreatment. The process is mature and reliable and has practical significance.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X787

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