碳源梯级利用模式下深度反硝化强化脱氮技术研究

发布时间：2018-03-30 16:23

  本文选题：碳源梯级利用　切入点：双污泥系统　出处：《哈尔滨工业大学》2015年硕士论文

【摘要】：城镇污水脱氮除磷过程中碳源不足问题一直是水处理行业中亟待解决的关键问题。本课题针对这个问题提出基于碳源梯级利用模式的深度反硝化脱氮除磷新工艺,即污水中的碳源先在厌氧阶段被聚磷菌利用释磷后,进入初级缺氧阶段被反硝化菌利用进行反硝化反应,这时污水中易被生物利用的碳源几乎消耗殆尽,再进入水解酸化阶段,剩余的不容易被生物利用的碳源将转化成为易被生物利用碳源,随后进入二级缺氧反应阶段进行深度反硝化,同时由于反硝化聚磷菌的存在,利用生物体内碳源在反硝化的同时进行过量吸磷,既保证了碳源的供给,又完成了磷的过量摄取。这样可以解决碳源不足问题,及由于碳源过多进入好氧阶段造成异养菌与自养菌的竞争问题。本工艺采用双污泥系统,即硝化污泥和反硝化聚磷污泥存在于两个完全独立的污泥循环系统,利于各功能菌群独立发挥各自优势。在室温下启动反应器,并在室温下对系统运行参数进行调整与优化,包括硝化液回流比(R)、污泥回流比(r)和水力停留时间(HRT)的优化研究,确定系统运行最优工况。研究结果表明,硝化液回流比R2≤160%时,系统对COD、TP和TN的去除效果随着硝化液回流比R2的升高而升高,在R2=160%时达到最大值,3种污染物的去除率分别为78.8%、88.0%和80.5%,而当R2=200%时,厌氧池释磷恶化,COD利用率降低,整个系统脱氮除磷效果不理想;污泥回流比r≤80%时,系统对COD、TP和TN的去除效果随着污泥回流比r的升高而升高,在r=80%时达到最大值,3种污染物的去除率分别为82.4%、90.8%和83.7%,而当r=100%时,污水实际HRT缩短,污泥浓度过高且易沉积,影响了整个系统脱氮除磷效果;HRT从24.00h缩短到16.00h后,系统仍有较好的脱氮除磷效果,TP和TN的去除率分别为80.7%和84.6%;而当HRT进一步缩短到12.00h后,厌氧段释磷量和缺氧池2反硝化除磷效果大幅度下降,好氧池硝化效果逐渐变差,此时TP和TN的去除率分别为45.3%和70.7%。故系统运行最优工况为R1=40%、R2=160%、r=80%,对于HRT而言,可考虑将厌氧池HRT缩短至1.50h左右,缺氧池1HRT控在2.00h左右,水解酸化池HRT控制在5.50左右,缺氧池2HRT控制在3.00h左右,接触氧化池HRT控制在4.00h左右。
[Abstract]:The shortage of carbon source in the process of nitrogen and phosphorus removal has been the key problem to be solved in the water treatment industry.In order to solve this problem, a new process of deep denitrifying nitrogen and phosphorus removal based on the carbon source cascade utilization model was put forward, that is, the carbon source in sewage was first utilized by phosphorus accumulating bacteria in anaerobic stage, and then phosphorus was released.In the primary anoxic stage, denitrification is carried out by denitrifying bacteria, and the carbon sources that are easily bioutilized in the sewage are almost exhausted, and then enter the stage of hydrolysis and acidification.The remaining carbon source, which is not easily bioavailable, will be converted into a bioavailable carbon source, and then deep denitrification is carried out in the second stage of anoxic reaction, at the same time, because of the presence of denitrifying phosphorus accumulating bacteria,Excessive phosphorus uptake by denitrification can ensure both the supply of carbon source and the excessive uptake of phosphorus.This can solve the problem of insufficient carbon source and the competition between heterotrophic bacteria and autotrophic bacteria due to the excessive entry of carbon source into aerobic stage.In this process, two sludge systems, nitrifying sludge and denitrifying phosphorus accumulating sludge, are used in two completely independent sludge circulatory systems, which is beneficial to each functional flora to play its own advantages independently.The reactor was started at room temperature, and the system operation parameters were adjusted and optimized at room temperature, including the optimization of nitrifying liquid reflux ratio (RN), sludge reflux ratio (R) and HRT (hydraulic retention time) to determine the optimal operating conditions of the system.When the sludge reflux ratio r 鈮，

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