【作者】 杨坤；

【导师】 余兆祥；

【作者基本信息】 同济大学 ， 应用化学， 2006， 硕士

【摘要】 鉴于含高浓度有机物和氨氮的焦化废水对环境造成的重大危害，其中有机物的进一步去除和生物脱氮已日益引起人们的重视。本试验采用同步硝化反硝化生物膜系统处理焦化废水，对生物脱氮过程中影响系统处理效果的一些因素进行了研究，以期为焦化废水处理类似的工艺过程提供一些参考。本文首先采用正交试验研究了生物膜法同步硝化反硝化系统中溶解氧、停留时间、pH等因素对有机物降解和生物脱氮的影响程度，从中确定最佳的COD（化学需氧量）降解工艺控制条件。研究结果表明：DO（溶解氧）为工艺影响最大因素，不同水平的DO条件下，系统COD去除率的极差达到58.61％。其他依次为pH值＞COD负荷＞HRT＞综合误差＞NH₃-N负荷。从而我们得出最佳工艺条件：HRT=44.1h；DO=3.5～4.0mg／L；pH=8。对氨氮影响因素的分析表明：HRT不小于40h时对氨氮的去除率可达95％左右，出水氨氮浓度小于5mg／L，且可以将氨氮几乎全部转化为硝态氮，同时反硝化可以达到较好的脱氮效果：DO在5.5mg／L下的硝化反应比较完全，而且总氮质量浓度也有降低，表明在这一阶段既发生了同步硝化反硝化；碳源质量和数量是影响反硝化效果的关键因素，如果不加入甲醇，反硝化率非常低，加入甲醇后，反硝化率大大上升；pH值是脱氮过程中的重要控制因素，微生物只能在一定的pH下生存，在7.5～8.5之间时最为适宜。对系统的动力学研究表明：当进水COD浓度在1500mg／L左右时，有机物的去除半速率常数为553.107mg／L，单位体积填料有机物最大去除速率为1667mg／m²．h；当进水氨氮浓度在300mg／L左右时，单位体积填料对氨氮的最大去除速率为5.7471mg／m²．h，而亚硝酸菌氧化氨氮的饱和常数为2.9954mg／L。对生物相的研究表明：生物膜中生长有多种微生物，其中大量的异养微生物能较好地利用有机碳源，在好氧条件下快速代谢废水中的COD。内部所形成的厌氧环境使反硝化微生物具有适合的代谢环境并可利用预先储存的基质进行反硝化。更多还原

【Abstract】 As the discharge of coking plant wastewater arouses great harm to environment, the removal of organic compound and the dinitrication in the coking plant wastewater gained much more attention day by day. In this paper, we choose simultaneous nitrification and denitrification process to treat the coking plant wastewater in order to offer some valuable reference for engineering apply, and study on factors which affect the treatment effect of the system.First we choose orthogonal test to investigate how factors such as DO HRT pH effect on the removal of organic compound and the dinitrication, and then confirm the best techniques conditions for the removal of organic compound. Hie result indicates that: DO is the most affective factor, and under different DO levels, the most difference of COD removal achieves 58;61 % .The other factors are pH>COD load>HRT>compositive error>ammonia load, thus we educe the best condition, HRT =44.1h; DO=3.5-4.0 mg/L; pH=8.The analyze on factors which effect on ammonia shows that: the ratio of ammonia removal can achieve 95% when HRT was no less than 40h, and the concentration of exit ammonia was less than 5mg/L; the nitrification can fully complete, and the quality concentration of total ammonia reduced, which suggested it happened nitrification and denitrification at the same time; the quality and amount of methanol is a key factor which effect denitrification, the ratio of denitrification was low without methanol while high within methanol; pH is a important factor during nitrification process, as the microorganism can only exist in certain pH, the best pH is about 7.5 to 8.5.The study on dynamics of system shows that: when the infall concentration of COD is around 1500mg/L approximately, velocity of organic compound removal is comparatively slow, and the half- velocity constant is 291.18mg/L, the maximal velocity of organic compound removal per cubage filling material is 28.25mg/m~2.h; and when the infall concentration of ammonia is around 300mg/L approximately ,the maximal velocity of ammonia per cubage filling material is 5.7471 mg/m~2.h, the saturated constant of nitritebacterium oxygenation is 2.9954mg/L.The study on microorganism shows that: there are many kinds of microorganism in the biofilm, and a great deal of aerobic microorganism in it can use the organic carbon metabolize COD in the wastewater under aerobic conditions. The anaerobic environment inside made dinitrification microorganisms have suitable metabolizing condition and go on dinitrification with beforehand storaging carbonate.更多还原