【作者】 李雨霏；

【导师】 韩洪军；

【作者基本信息】 哈尔滨工业大学 ， 市政工程， 2013， 博士

【摘要】 曝气生物滤池是近年发展起来的污水处理新工艺，具有高效去除SS、COD和脱氮作用，占地面积小、费用低和抗冲击负荷能力强等特点。前置反硝化生物滤池工艺是将A/O工艺与曝气生物滤池相结合，具有曝气生物滤池的所有优点，但在理论研究和实际应用中仍存在预处理效果欠佳、反硝化效率低以及同时碳化硝化曝气生物滤池硝化效率低等问题。本文针对前置反硝化生物滤池存在的问题，提出了水解沉淀-前置反硝化生物滤池组合工艺，全面分析了水解沉淀池预处理效能和机理，通过实验室模型实验和现场试验，考察了反硝化生物滤池（Denitrification biofilter,简称DN池）和碳化硝化曝气生物滤池（Carbonization and nitrification biological aerated filter，简称CN池）的处理效能和提高反硝化效率和硝化效率的方法，并推导出底物动力学模型，进一步全面了解了前置反硝化生物滤池除碳脱氮原理，对其设计、开发和应用推广具有实际意义。通过实验室模型分析了沿水解沉淀池高度主要污染物浓度变化规律，以及影响沉淀池处理效能的主要因素，结果认为污泥量和污泥层高度是决定水解沉淀池对污染物去除能力的主要因素。通过对水解沉淀池中污泥抽滤后测间隙水中氨氮浓度以及烧杯吸附实验，证明了沉淀池对NH₄⁺-N的去除机理主要为吸附作用，NO₃^--N少量被吸附，NO2--N的去除主要由于反硝化的作用。在相同进水水质和运行条件下，通过对比实验证明，作为反硝化生物滤池的预处理工艺，水解沉淀池的出水可生化性提高要大于普通沉淀池，预处理效果前者明显高于后者。DN池对TN平均去除率为37.4%，对有机物的去除大部分是由于滤料截留和进水口处DO消耗，其次是作为反硝化反应的电子供体。硝态氮的反硝化作用主要发生在滤池中上部，DN池入口DO较高是DN池内反硝化效率低的主要原因之一。对反硝化作用的影响因素研究表明，反硝化速率随着温度的升高而增大。COD/NO₃^--N比小于14.0时COD是反硝化反应的限制因素，而大于此值对反硝化影响不大。水力负荷提高，DN池含氧层高度上移，DN池对COD和NO₃^--N的总去除率均呈下降趋势。综合考虑COD和的NO₃^--N去除，回流比为130%比较适合。将部分CN出水回流入沉淀池可有效的降低DN池内有氧区高度，DN池反硝化率有较大的提高。从减少对沉淀池内COD的消耗和水力负荷冲击的角度来讲分配比1:1为宜。调整进水DO浓度为0并延长DN池反冲洗时间发现， DN池可能出现厌氧氨氧化现象。稳定运行时CN池出水各项指标可以满足《城市污水处理厂综合排放标准》中的一级B标准。考察了温度、氨氮和COD的容积负荷、水力负荷对CN池的影响，实验结果证明，影响因素对氨氮去除影响显著，对有机物去除影响较小。采用硝化细菌在载体表面空间占位的方法强化了CN池硝化作用，结果显示，此种方式能够提高载体上硝化细菌的比例和氨氮的去除效率，但硝化作用的强化程度仍决定于进水的营养结构。采用微生物纯培养方法并结合扫描电镜观察等手段，研究了CN池和DN池生物膜形态和微生物优势菌群结构,考察了在一定的反冲洗模式和强度下，用各功能菌群的生物活性、生物量及二者的乘积考察了反硝化生物滤池和曝气生物滤池菌群功能的恢复。用最大可能计数法计算分析了各功能菌群生物量，其结果充分证明了的对污染物的降解功能与相应微生物功能群体的活性和数量有着必然的联系。以条件假设和微元物料衡算为基础，在高、中、低不同底物浓度条件下，首次分段建立了CN池内有机物去除动力学数学模型以及有机物竞争条件下氨氮去除动力学数学模型，同时建立了以有机物和硝态氮为基质的双底物反硝化动力学模型。更多还原

【Abstract】 The increasingly stringent in sewage discharge standard is generally the trend ofdevelopment in the world recently. It was impossible to meet land use, noise, especiallyits total nitrogen effluent limitations by conventional secondary bio-treatment.Biological aerated filter is a new sewage treatment technology developed in recentyears,which was characterized for the efficient removal of COD and SS, nitrificationand denitrificationand, low land usage, less investment in capital construction andoperation cost, convenient management and capacity of anti impact load etc. The actualcontradiction induced by land resources shortage, large sewage, high sewage dischargestandard can be solved by biological aerated filter process. There are few documentabout pre-denitrification aerated biofilter and its application is less in practice. The keytechnologies of this technology are pretreatment technology selection, the pretreatmentdegree of important indicators, the control on COD/NO₃^--N and reflux ratio ofdenitrification influent and biofilter material etc.According to problems Existing in practical engineering application and theoreticalresearch on pre-denitrification aerated biofilter, hydrolysis precipitation andpre-denitrification aerated biofilter combined process was put forward. Respectivelybased on the hydrolyzsis sedimentation tank, Denitrification biofilter （DN biofilter forshort）and Carbonization and nitrification biological aerated filter （CN biofilter forshort）, a comparatively extensive study and analize was made by lab and in field.Under stable operation condition, the average removal of SS, COD and TN was57.9%，45.9%and55.0%respectively with12～16.5℃and hydraulic loading of0.6m3/m2h. The change law of main pollutant consistence along longitudinal directionand the influence factors on hydrolyzsis sedimentation tank performance were studiedin lab. The result was height and concertration of suspended sludge layer in the tank isthe main determinants of pollutants removal rate. To sum up, the effluent of hydrolysisprecipitation can meet the qualification of pretreatment for pre-denitrification aeratedbiofilter.The test results of Air pump filtration and the adsorption test for sewage and sludgein the tank displayed, that the ammonia concentrations of interstitial water in sludgealways outclass that of influent. All above results demonstrated that NH₄⁺-N removalmechanism is adsorption by the sludge in the tank, and has slight sorption for NO₃^--N,but it was been shown denification for NO2--N. Hydrolysis is happened in thesedimention but hydrolysis degrees were weaker. The contrast data of pretreatmenteffect under the same conditions of influent quality and operation, hydrolysissedimentation tank is vioursly higher than common sedimentation tank as pretreatmentprocess of denitrification biobiofilter. The average removal rate of TN and COD in DN biofilter is respectively37.4%and34.1%at hydraulic retention time of1.4h and the influent was consist of the CNbiofilter effluent at100%reflux and the effluent of sedimention. Most of COD isremoved because of interception of biofilter and DO consumption firstly, secondlybecause it was used as electron donor of denitrification. Denitrification of NO₃^--Nhappened at upper part of DN biofilter, and higher DO concentration at the entrance ofDN biofilter is the one of main reasons on low denitrification efficiency.The studies on the denitrification influence factors showed, that denitrificationefficiency increased with temperature raised. COD/NO₃^--N of14.0was taken as criticalvalue, but COD will be the main limiting factor less than that, and above that,it haslittle effect on denitrification larger than that. With hydraulic loading rising, the biofilteroxidation layer hight moved up, total removal rate of COD and NO₃^--N in DN biofiltershowed the downtrend. By comprehensive consideration, the reflux rate of130%isrelatively suitable.The oxidation layer hight of biofilter is availably reduced and dinitrification rate ofDN biofilter is raised when the CN effluent partially returned into the sedimental tank.Shunting ratio is1:1is relatively suitable considering decreasing COD consume andhydraulic loading shock in sedimental tank. Anammox is detected when DOconcertration in DN biofilter is zero and backwashing time of DN bioflter is prolonged.All indexes can meet the First Grade Standard of GB8978—1996during stablerunning. The influence of temperature, volume loading of NH₄⁺-N and COD,hydraulic load were studied. The results showed that influence infactors had significanteffect on NH₄⁺-N removal and had less effect on COD removal.Nitrification was strengthened by method of nitrifying bacteria occupying firstlyon the surface of biofilter material. The results showed that, it could improve thequantities of nitrifying bacteria in biofilter material and NH₄⁺-N removal rate. But theenhancement degree of nitrification was still determinde by nutrient structure ofinfluent.By conventional microbial culture methods combined with scanning electronmicroscope, the biofilm pattern of CN biofilter and DN biofilter and dominantmicroorganism structure were studied. Activity recovery of microbial community,located at medium in denitrification biofilter （DN） and biological aerated filter （CN）,was studied by biological activity, biomass, and product of both under a mode andstrength of backwashing. The biomass of functional micro-flora was evaluated byMaximum Probable Number. All above results demonstrated was proved that pollutantbiodegrade maybe inevitable related to the corresponding activity and quantities offunctional micro-flora.On the basis of the hypothetical conditions and the micro-unit material balance,kinetic mathematical model of organic and NH₄⁺-N removal in the organic competitive condition in CN biofilter were piecewise established under high middle and lowsubstrate concentration. Meanwhile, kinetic mathematical model of double substratesdenitrification was established, organic and NOx--N as substrate.更多还原