低碳源污水同步脱氮除磷工艺应用研究

【作者】 周子鹏；

【导师】 高健磊；

【作者基本信息】 郑州大学 ， 环境工程， 2009， 硕士

【摘要】 近年来,随着居民生活水平的提高与工业、经济的发展,进入城市污水处理厂的污水N、P含量不断增加,从而成为较难满足传统生物脱氮除磷工艺处理的低碳源污水。同时,我国大中型城市污水处理厂大多存在建设标准低,多数无脱氮与除磷功能等特点。而国家法规和政策对大中城市污水处理厂又提出了更严格的氮磷排放要求。因此研究低碳源污水同步脱氮除磷工艺具有重要意义。本文研究了污水同步脱氮除磷工艺的发展与变化,探讨了A²/O工艺同步脱氮除磷的矛盾与问题,并对A²/O工艺的改良进行了研究。以某污水处理厂二期改扩建工程改良A-A²/O工艺为模拟对象,并以污水处理厂实际污水作为试验用水。试验实际进水水质:CODcr在244-641 mg/L、BOD₅在145-355 mg/L、NH₄⁺-N在40.5-87.6 mg/L、TN在50-105 mg/L、TP在2.5-9 mg/L,BOD₅/TN均值在3左右,BOD₅/TP均值在35左右。进水BOD₅/TN＜4的城市污水即称之为低碳源污水。试验采用100%的污泥回流量和混合液回流量,研究了溶解氧、污泥龄、运行工艺和进水方式的影响。得出以下结论:1.对低碳源污水（C/N为3）的同步脱氮除磷工艺,较高的溶解氧可以抵抗进水氨氮负荷的冲击,保证出水小于1mg/L,但容易使活性污泥老化和自溶。溶解氧的合理调控,可以提高总氮去除率。2.除碳和脱氮率基本不受污泥龄（12＜SRT＜20d）的影响,但较高的污泥龄有助于抵抗进水TN负荷的冲击;泥龄越低,总磷去除率越高。3.由于进水碳源较少（C/N为3）,使同时脱氮和除磷存在碳源竞争问题。在相同的工艺参数、影响因素和进水水质下,采用倒置A²/O工艺对于总氮的去除优于A²/O工艺,出水总氮浓度比A²/O工艺普遍低5mg/L,但出水总磷浓度比A²/O工艺略高;4.流量比为1/2的进水方式,对倒置A²/O工艺和A²/O工艺的除碳、脱氨影响不大。多点进水的A²/O工艺,出水总氮可降低5 mg/L,但对总磷去除帮助不大。多点进水的倒置A²/O工艺,对总氮去除影响不大,出水总氮比单点进水降低2-3 mg/L,但可提高系统抗TN负荷的冲击;总磷的去除率提高较多,出水总磷均为0.5-1.0 mg/L之间。本试验研究对于当前传统二级生物处理工艺污水处理厂的升级改造,具有借鉴和指导作用,并为同种类型污水处理厂的设计提供相应依据。更多还原

【Abstract】 In recent years,with the improvement of living standards and industrial and economic development,municipal wastewater have also taken place in a corresponding change,in which N,P concentrations increased,making it more difficult to meet the traditional process of biological nitrogen and phosphorus removal.At the same time,most of Chinese large and medium-sized municipal wastewater treatment plant are low standard,and the majority of them have non-functional,such as nitrogen and phosphorus removal characteristics.On the other hand,the national laws,regulations and the policy proposed the stricter nitrogen phosphorus emission standard to the large and medium-sized municipal wastewater treatment plant.So it is important to study the nitrogen and phosphorus removal simultaneously process for low-carbon sources of sewage.This paper studies the development and change of nitrogen and phosphorus removal simultaneously process,explores the contradictions and problems of nitrogen and phosphorus removal simultaneously in A²/O process and summed up the improvement of A²/O process.We use the improved A-A²/O process of one sewage treatment plant as a simulation object and use actual sewage water of the other sewage treatment plant as a pilot. The actual water quality tests:CODcr 244-641 mg/L,BOD₅ 145-355 mg/L,NH₄⁺-N 40.5-87.6 mg/L,TN 50-105 mg/L,TP 2.5-9 mg/L,BOD₅/TN≈3,BOD₅/TP≈35.It is called the low-carbon sources of municipal wastewater because of the BOD₅/TN＜4.We,using 100%of the sludge and mixture return flow,mainly study the impacts of DO, SRT,Running processes and influent way in reaches.And have following conclusions:1.For nitrogen and phosphorus removal simultaneously process of the low-carbon sources sewage,a higher DO can resist the impact of influent ammonia load to ensure that the effluent is less than 1mg / L.However,activated sludge is easy for the aging and autolysis.Reasonable DO will help us to improve nitrogen removal rate.2.SRT（12＜SRT＜20d） does not affect the rate of carbon and ammonia removal,but a higher SRT can resist the impact of influent TN load.the lower SRT,the higher TP removal rates. 3.As the water less carbon（C/N of 3）,there are carbon competition in the Nitrogen and phosphorus removal simultaneously process.In the same process parameters,influencing factors and water quality,the effluent TN of inverted A²/O process is better than it of A²/O process.Effluent TN concentrations is generally low-5mg/L than the A²/O process,but the effluent total phosphorus concentration than the A²/O process is slightly higher.4.In addition to carbon,the removal of ammonia is not affected by 1/2 influent way in the A²/O process and inverted A²/O process.For the multi-point water A²/O process,the effluent TN can reduce 5 mg/L,but it has little help to the TP removal.It has little effect on TN removal,reduces the total nitrogen 2-3 mg/L and resists the impact of influent TN load for using multi-point water inverted A²/O process.Also we found that the TP removal rate increases more,and the effluent TP is 0.5-1.0 mg/L.This study has the role of reference and guidance for conventional secondary biological treatment process of sewage treatment plant upgrade,and provides the appropriate basis for the same types of sewage treatment plants.更多还原