【作者】 李振华；

【导师】 杨开；

【作者基本信息】 武汉大学 ， 市政工程， 2010， 博士

【摘要】 针对污水分散处理时规模较小,进水浓度偏低等特点,提出一种较目前常用的小流量污水处理工艺(SBR工艺、MBR工艺等)更为简单、高效、低耗的接触氧化过滤分离一体化生物反应器(Contact oxidation Filtration separation integrated Bioreactor,简称CFBR),其以曝气生物滤池(BAF)为原型,采用活性炭滤料,借鉴慢滤池和滤饼过滤原理,同时秉承序批式生物膜法(SBBR)操作灵活的优势,将生物接触氧化法和高效过滤分离有机耦合在一起,可在一个反应器内完成污水的生物氧化及悬浮物过滤分离的过程。论文从CFBR反应器处理城市污水时的处理效能、污染物降解机理、流态特性、反应动力学等方面,对CFBR工艺进行较系统的研究,表现如下：(1)CFBR反应器出水水质好,占地面积小,抗冲击负荷能力强,能耗低,运行方式灵活,自动化程度高,能够满足污水分散处理与回用的需求。(2)CFBR反应器处理城市污水的最佳工艺参数为：水力负荷为3.8m3/(m3·d)、接触氧化阶段反应器内DO浓度2～3mg/L、过滤分离阶段初始滤速为5m/h、水温为22～25℃。在最佳工艺参数的条件下,CFBR反应器对COD、氨氮、总氮及浊度平均去除率分别为94.8%、81.4%、64.6%及97.5%,反应器出水中COD、氨氮、总氮及浊度分别为6～30mg/L,1.65～7.31mg/L、4.95～12.62mg/L及1～10 NTU。总磷去除效果欠佳,最高平均去除率为63.0%,出水总磷浓度为0.64～1.57mg/L。(3)CFBR反应器对污染物降解机理。在接触氧化阶段,有机物和溶解氧经液相传送到滤料表面的生物膜上,被生物膜内的微生物所分解与转化,最终形成各种代谢产物(CO2、水等),污水中的氮主要是通过同步硝化反硝化(SND)方式被去除的,而部分磷的去除,主要是由微生物的同化作用而引起的；在过滤分离阶段,有机物的少量去除是以颗粒状滤料与吸附生长滤料表面的生物膜为主要处理介质,通过吸附阻截和生物代谢的共同作用实现有机物的去除,而悬浮颗粒的去除主要经历迁移和附着两个步骤。(4)CFBR反应器的流态特性。CFBR系统在流态上呈完全混合式,在有机物降解方面呈时间上的推流,本质上是隶属于完全混合间歇反应器(CMB)。(5)CFBR系统动力学方程。针对CFBR系统的运行特点和对有机污染物的降解机理,建立CFBR系统的动力学模型,即：模型能较好地反映CFBR系统的实际运行状况。更多还原

【Abstract】 A new contact oxidation filtration separation integrated bioreactor (CFBR) was developed to decentralized wastewater treatment of low influent concentration and small-scale sewage. The idea relies on BAF (BAF is a submerged media wastewater treatment unit that combines aerobic biological treatment and biomass separation by depth filtration) prototype and principles of slow and cake filtration (A sticky mat of biological matter, called a "cake", forms on the media surface, where particles are trapped and organic matter is biologically degraded).The CFBR was packed with activated carbon and operated in a batch mode to treat a municipal wastewater. The CFBR combines the advantages of the biological contact oxidation process and the filtration bed in one system. Moreever, as the use of the CFBR, it can complete biological oxidation of sewage and filtration and separation of suspended solids in a reactor.In this study, the CFBR was operated in a batch mode to treat municipal wastewater. The objective of the paper was to evaluate the processing performance, explore degradation mechanism of pollutant and flow pattern, and establish kinetics model in the CFBR.The research indicated that it is efficient and feasible to treat decentralized wastewater by the CFBR.It can be proved as following:(1) The CFBR for decentralized wastewater treatment has some advantages such as lower effluent SS value, small land requirement, good power consumption, high degree of automation operation and stronger resistance to influent shock load.(2) The optimal operation parameters of the CFBR were determined as follows: Hydraulic loading of 3.% m3/(m3.d), DO of 2-3 mg/l in contact oxidation phase, and initial filtration velocity of 5m/h in filtration separation phase.Good performance of the CFBR was achieved under the optimal operation parameters. The total efficiencies of COD, NH4+,TN and turbidity removal in the CFBR were 94.8%,81.4%,64.6% and 97.5%(average value). The effluent concentration of COD,NH4+-N, TN and turbidity in the CFBR were 6～30mg/L,1.65-7.31 mg/L,4.95～12.62mg/L and 1～10ONTU. However, the CFBR showed that it seemed not to be effective in phosphorus removal.Maximal efficiency of TP removal was 63.0%.TP value of the CFBR effluent was 0.64～1.57mg/L.(3) The degradation mechanism of pollutant of the CFBR was explored.In contact oxidation phase, the organic substrate and DO goes into the attached growth biofilm. They are both utilized by the biofilm, and are degraded to CO2 and H2O in the end.The mass balance would show overall loss of nitrogen, which would logically be assumed to be simultaneous nitrification-denitrification (SND) in the CFBR.And partial TP removal is due to the normal absorption of microorganisms’growth.In filtration separation phase, a small amount of organic matter removal is attributed to granular filter media and attached growth biofilm. Through the interception and microbial metabolism, they achieved organic matter removal.And the removal of SS is mainly through two steps (Migration and adhesion).(4) The Flow pattern of the CFBR was completely mixed. But from organic matter degradation, the CFBR was plug-flow in terms of time.So, in essence, the CFBR was completely mixed batch reactor (CMB).(5) According to the operational characteristics of the CFBR and the degradation mechanism of organic pollutants, the kinetics model of the CFBR was established. The formula of kinetics model was The kinetics model was appropriate and feasible to describe the operational conditions of the CFBR system.更多还原