T型氧化沟的生物除磷脱氮机理及效果分析

Effect analysis and mechanism for biological nitrogen and phosphorus removal of T oxidization ditch

生物脱氮是指利用微生物将含氮化合物中的氮转化为氮气,它分为硝化和反硝化两个过程.生物硝化作用是指在好氧条件下,微生物将氨氮氧化成硝酸盐;生物反硝化是指硝酸盐在缺氧的条件下,被微生物还原为氮气的过程.生物除磷是指利用聚磷菌一类的微生物,在一定条件下过量地从外部环境摄取磷,并将磷以聚合的形态贮藏在茵体内,形成高磷污泥,通过排泥达到从污水除磷目的.T型氧化沟由Ⅰ,Ⅱ,Ⅲ三沟组成,三沟可以交替工作,按6个或8个阶段运行.通过不同时段调整转刷的转速,满足除磷脱氮所需条件.Ⅰ,Ⅲ两沟兼有缺氧、厌氧、沉淀功能,可作为硝化反应(曝气)池,又可作为反硝化反应池,具备同时去除COD,BOD及除磷脱氮效果.邯郸市东郊污水处理厂采用T型氧化沟工艺,多年的运行结果表明:平均NH3-N的去除率为93.8％,平均TN的去除率为64.4％,总平均去除率达79.1％,平均磷的去除率为77％左右.T型氧化沟工艺省去了二沉池及污泥回流装置,有较好的除磷脱氮效果,且易于实现自动控制,适宜我国气候温和、水温不大高的地方推广使用.

Bio-denitrification is a process that nitrogenous compounds are converted in to nitrogen by micro-organism, which encompasses nitrification and denitrification. NH3-N is converted in to nitrate under the condition of oxic, which is termed as nitrification. In the process of denitrification, nitrate is converted in to nitrogen under the condition of anoxic. Biological phosphorus removal is a process that phosphorus-accumulating bacteria are utilized to absorb phosphorus excessively from the exterior environment and help store polyphosphate in the bodies, and then form high phosphorus contained sludge, which can be removed by sludge discharge. T oxidization ditch consists of three ditches, which work in turns. The operating period of T oxidization ditch has six or eight phases, and the rotational speed of rotor-brush can be adjusted to meet the need of nitrogen and phosphorus removal. Ⅰ ditch or Ⅲ ditch is used as both a nitrification tank and a denitrification tank in which anoxic, anaerobic, and settlement work together. The operating result of Handan Eastern Suburban Wastewater Treatment Plant shows that the average removal rate of NH3-N is 93. 8%, TN 64.4%, and the removal rate is 79. 1%. The average removal rate of phosphorus is 77%. T oxidization ditch process is a very efficient wastewater treatment technology with advantages that nitrogen and phosphorus can be removed at the same time with no requirement for secondary settlement tank and sludge return equipment, and easy to realize automatic control. Therefore, it can be widely used in the place where air temperature is moderate and water temperature is not high.