【作者】 张献旭；

【导师】 杨基先； 马放；

【作者基本信息】 哈尔滨工业大学 ， 微生物学， 2007， 硕士

【摘要】 水体富营养化是当今我国水环境面临的重大问题,严重地阻碍着我国国民经济的发展。目前生物脱氮已经成为废水中去除氮素污染的最有效的方法之一。传统的生物脱氮由于作用于各脱氮步骤中的不同菌群对于营养及溶解氧的要求各异,造成了生物脱氮工艺复杂,限制了在实际工程中的应用。异养硝化的研究,是对传统硝化理论的丰富与突破,为污水脱氮引入全新的概念。异养硝化生物脱氮技术因具有缩短脱氮历程、节省碳源、提高处理能力、降低动力消耗等优点而被广泛关注。本课题从生物陶粒脱氮反应器中筛选得到异养硝化效果比较好的两株菌Z5和Z8。采用丁二酸钠-硫酸铵培养基培养细菌进行研究,经2d培养,两株异养硝花菌对氨氮的去除率在65%以上,对COD的去除率在40%以上。对其进行生理生化指标鉴定及16SrDNA序列分析,将其鉴定到属,可基本确定前者为假单胞菌属的绿脓杆菌Pseudomonas aeruginosa ,后者为不动菌属Acinetobacter sp ,其相似性分别达到了100%和99%。对菌Z5和Z8进行进一步的氮素轨迹分析,其最适碳氮源分别为丁二酸钠和硫酸铵,在最适碳氮源条件下,菌株Z5和Z8对氨态氮的去除率可分别达到57.95%和63.86%,同时这两株菌对硝态氮的去除率分别达到了86.93%和89.57%,氨氮的初期利用是促进菌体生长的关键因素,并且菌Z5和Z8具有很强的反硝化功能。菌的生长过程中,亚硝态氮和硝态氮没有明显积累,对所筛异养硝化菌的同步脱氮机理进行初步探讨。将所筛选的异养硝化细菌扩大培养后建立SBR反应器进行了氨氮去除的试验研究。在SBR反应器进入稳定运行阶段时,可以观察到系统对于氨氮的去除率稳定在82.96%左右。表现出较好的氨氮去除效果,出水亚硝酸盐含量一直维持在较低的水平,其最大值不超过3.84mg/L。COD的平均去除率为54.72%,基本实现了同一反应器中的有机物和氨氮的共同去除。PCR-DGGE图谱分析表明,微生物多样性与废水的处理效果出现协同变化的特征,1d与15d微生物群落结构相似程度高为75%,1d与30d相似性最低为52.94%,15d与30d相似性为70.59%,所筛选两株异氧硝化细菌Z5, Z8成为SBR反应器的优势菌群。更多还原

【Abstract】 The nitrogen pollution is the main reason causing water eutrophication, and the removal of nitrogen has become a hot topic in wasterwater treatment field as water eutrophication become even worse. Because of the different requirement of the different nitrifiers and denitrifiers for nourishment , the process of removal of nitrogen is very complex and the application is limited. The find of heterotrophic nitrification provides a new method for developing the application of the biological removal of nitrogen. Because of their advantages such as enhancing the treatment effect, reducing the area and reducing the treatment process flow etc, heterotrophic nitrification process has been widely put attentions.Two strains of heterotrophic nitrifiers, named Z5 and Z8, is isolated from bio-ceramic reactor. The analysis based on 16SrDNA showed that the strains are the relative of Pseudomonas aeruginosa and Acinetobacter sp. with 100% and 99% sequence similarity respectively. Under the conditions, the ammonium removal rate reached 57.95% and 63.86% respectively. The initial removal of ammonium is the critical factor to the organism growth. Meanwhile, 86.93% and 89.57% of the NO3—N removal rate can be gained, which indicated that Z5 and Z8 possessed high effective denitrification. During the whole growth of Z5 and Z8, there is no nitrite and nitrate accumulation.The process of removing ammoniac nitrogen was done by setting the heterotrophic nitrification bacteria on the sequencing batch reactor. And the efficiency of ammoniac nitrogen removal can reach up to 82.96%, when the reactor works smoothly. The nitrite concentration of effluent was in a low level and the maxiuma value was no more than 3.84mg/L. At the same time, the efficiency of COD was 54.72%, which presents the coinstantaneous removing of both organic and ammoniac nitrogen.The PCR-DGGE profiles showed that shift of microbial diversity correspond to the effect of nitrate removal.1d and the 15d similarity is 75%, which microbial diversity is the highest. 1d and the 30d similarity is the lowest which is just 52.94%, 15d and the 30d.similarity is 70.59%. Z5, Z8 were dominated bacteria in sequencing batch reactor.更多还原