基于好氧污泥颗粒化的深度脱氮工艺研发

发布时间：2018-11-03 12:56

【摘要】：为满足不断提高的城镇污水总氮排放标准,建设集约型水处理设施。本文以好氧污泥颗粒化为核心,分别研究传统模式及厌氧好氧交替模式下絮状污泥的颗粒化进程,及好氧颗粒污泥的脱氮机理。针对实际生活污水特征,分别采用SBR工艺和水解酸化+SBR耦合工艺培养好氧颗粒污泥,并分析其除碳脱氮能力变化。主要研究结果如下:(1)采用SBR反应器,以乙酸钠为碳源,培养模式分别为传统的快速进水直接曝气模式、厌氧慢速推流进水后曝气模式及厌氧搅拌进水后曝气模式。其中厌氧推流进水模式培养出结构紧凑、表面光滑的好氧颗粒污泥,反应器内污泥浓度约为12.0g/L,平均粒径2.0-3.0mm,TN去除率达到96%,并能维持长期稳定运行。(2)好氧颗粒污泥生物脱氮建立在同步硝化反硝化机理上,由于颗粒污泥粒径较大,氧气和基质在颗粒中的传质受限,在颗粒内部会形成表面好氧、内部缺氧结构。曝气强度为1.0L/min,反应器内溶解氧为2.5mg/L时,好氧颗粒污泥硝化反硝化速率相当,出水TN小于3mg/L。SEM显示颗粒污泥内部微生物呈现明显分层聚集情况,外层为缠绕紧密的短杆菌,内部则主要是球菌。在碾碎好氧颗粒污泥破坏其分层结构后,出水TN升高至10mg/L。(3)直接利用实际生物污水培养好氧颗粒污泥难度较大,经过70d的培养没有在反应器观察到颗粒污泥形成,TN去除率约为70%。通过前置水解酸化对原污水进行预处理后,再用厌氧推流进水模式培养培养好氧颗粒污泥,能够加速絮状污泥颗粒化。经70d培养反应器中出现粒径约为200-300um的颗粒污泥雏形,虽然絮状污泥仍占主导地位,但出水TN浓度下降至10mg/L以下,TN去除率达到80%。(4)直接利用成熟好氧颗粒污泥处理实际废水,反应器能够维持稳定运行,且出水水质较好,出水COD小于25mg/L,出水TN约5mg/L。
[Abstract]:In order to meet the increasing standards of urban sewage total nitrogen discharge, intensive water treatment facilities were constructed. In this paper, the granulation process of flocculating sludge and the mechanism of denitrification of aerobic granular sludge under traditional and anaerobic aerobic alternate modes were studied respectively with aerobic sludge granulation as the core. According to the characteristics of domestic sewage, aerobic granular sludge was cultured by SBR process and SBR coupling process of hydrolysis and acidification, and the change of carbon and nitrogen removal capacity was analyzed. The main results are as follows: (1) by using SBR reactor and sodium acetate as carbon source, the culture models are the traditional direct aeration mode of rapid influent, the post-aeration mode of anaerobic slow pushing flow and the post-aeration mode of anaerobic stirred influent. The aerobic granular sludge with compact structure and smooth surface was cultivated in the anaerobic push-flow influent mode. The sludge concentration in the reactor was about 12.0g / L, and the average diameter of 2.0-3.0mmTN was 96%. The biological denitrification of aerobic granular sludge is based on the mechanism of simultaneous nitrification and denitrification. Internal anoxic structure. When the aeration intensity was 1.0 L / min and the dissolved oxygen in the reactor was 2.5mg/L, the nitrification and denitrification rate of aerobic granular sludge was the same, and the TN of effluent was smaller than that of 3mg/L.SEM. The outer layer is a close-wound short bacillus and the inner is mainly cocci. After crushing aerobic granular sludge to destroy its stratified structure, the TN of effluent increased to 10 mg / L. (3) it was difficult to culture aerobic granular sludge directly from actual biological sewage. After 70 days of culture, no granular sludge formation was observed in the reactor. The removal rate of TN is about 70%. After pretreatment of raw wastewater by pre-hydrolysis acidification, aerobic granular sludge was cultured by anaerobic pushing influent mode, which could accelerate the granulation of flocculating sludge. After 70 days of culture, the granular sludge with diameter of about 200-300um appeared in the reactor. Although the flocculating sludge was still dominant, the concentration of TN in effluent decreased below 10mg/L. The removal rate of TN is 80%. (4) the reactor can maintain stable operation and the effluent COD is less than 25 mg / L, and the effluent TN is about 5 mg / L when the mature aerobic granular sludge is used directly to treat the actual wastewater.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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