【作者】 高守有；

【导师】 彭永臻；

【作者基本信息】 哈尔滨工业大学 ， 市政工程， 2006， 博士

【摘要】 由于氮磷等植物性营养盐引起的水体富营养化问题仍然是当今世界各国面临的主要水体污染问题之一。随着经济社会的发展,我国的污水处理事业得到了不断的发展,污水处理率逐年升高,但是水体富营养化问题依然严重。从整体上来说,我国污水厂运行管理水平较低,运行成本偏高,处理效果较差;同时对于新技术的开发能力和引进技术的吸收水平较低。逐步推广和发展污水脱氮除磷技术,实现已建成污水处理厂的脱氮除磷运行和节能改造,开发高效的脱氮除磷新技术显得尤为重要。本文采用目前在国内城市污水处理厂中得到广泛使用的Orbal型氧化沟为研究对象,采用有效容积为330升的中试系统分别研究了典型城市污水和低碳比的生活污水条件下,强化脱氮的控制条件和节能运行策略,分析了Orbal氧化沟生物脱氮的机理,旨在为污水处理厂的改造提供参考数据。同时针对生活污水碳氮比低、反硝化过程碳源不足的特点,首次提出并成功实现了常温条件下,控制低溶解氧实现实际生活污水短程硝化的理论方法。采用Orbal氧化沟处理城市污水的试验过程中,分别考察了不同溶解氧浓度、不同碳氮比和不同污泥回流比条件下,系统的总氮去除效果,提出了限量曝气,降低外沟道溶解氧,强化外沟内同时硝化反硝化作用实现强化脱氮和节能运行的方法。在水力停留时间为16.5小时,污泥浓度为3000mg/L,污泥回流比为100%,外沟,中沟和内沟DO分别为0.4mg/L,1.5mg/L和2.5mg/L的条件下,实现总氮去除率平均达到75.2%,出水总氮浓度在10mg/L以下。采用Orbal氧化沟处理实际生活污水的过程,研究了在原水低碳氮比条件下,实现Orbal氧化沟强化脱氮的控制方法:采取低溶解氧,高污泥浓度和控制适当的污泥回流比实现利用内碳源的同时硝化反硝化作用;在原水平均碳氮比为2.75,水力停留时间控制在16.5小时,污泥浓度控制在5500mg/L,污泥回流比为150%的条件下,通过控制外沟,中沟和内沟的溶解氧分别为0.1,0.4和0.7mg/L,实现了平均总氮去除率达到72.1%。随着总氮去除的加强,系统成功克服了主要由于污水水质引起的非丝状菌膨胀;同时在低溶解氧运行过程中,未发生丝状菌膨胀。对于中试系统中同时硝化反硝化生物脱氮的发生机理进行了探讨。采用批次正交试验对于新的微生物菌种(自养反硝化,异养硝化和好氧反硝化菌)对于同时硝化反硝化过程的作用做了定性评价。结果显示,这些能够进行非常规更多还原

【Abstract】 Eutrophication, which is caused by excessive discharges of nitrogen and phosphorurs, is still the main water pollution problem worldwidely. With the development of ecomomic and society, the projects of wastewater treatment have been greatly developed, and the ratio of wastewater disposal keeps increasing in the recent years. However, the problem of eutrophication still remains seriously. In general, the operation technique of wastewater treatment plants relatively lags behind in our country, with high cost and worse effluent water quality. At the same time, many efforts should be made to develop novel processes and improve the understanding of the new technique. It becomes urgent to keep popularization and development of biological nutrient remval, and realizing the operation and update of the existed wastewater treatment plants (WWTPs) to get nutrient removal with low costs.In this study, a pilot-scale Orbal oxidation ditch with 330 liters working volume was used to investigate nitrogen removal and cost-efficient operation, and to give supports to the update of the existed WWTPs. Both typical municipal wastewater and low C/N domestic wastewater were used to carry out the experiment. Meanwhile, because the low C/N of the domestic wastewater, which would make the denitrification processs lack of carbon source, a new technique to realize partial nitrification only by low dissolved oxygen control was put forward, treating domestic wastewater at ambient temperature.During the study of Orbal oxidation ditch treating domestic wastewater, operation parameters, such as different dissolved oxygen, C/N ratio and sludge recycle flow rate, which would influence nitrogen removal were analyzed, in order to provide valuable data to the real WWTPs. Practical methods, such as to limit oxygen supply and lower the DO concentration in outer channel, were proposed to enhance nitrogen removal performance and save the energy. Under hydraulic retention time of 16.5 hours, mixed liquor suspended solids (MLSS) concentration of 3000mg/L, sluge recycle flow rate of 100%, the DO of outer, middle and inner channel of 0.4, 1.5 and 2.5mg/L, respectively, average total nitrogen removal efficiency could reach 75.2%, with effluent total nitrogen concentration of less更多还原