【作者】 张立国；

【导师】 李建政；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2012， 博士

【摘要】 环境污染和能源危机是困扰社会经济可持续发展和人类生存的两大难题。有机废水的厌氧生物技术将污染治理与能源回收有机结合，成为当前解决环境污染和能源短缺的一条重要途径，如何进一步提高厌氧生物反应器处理效能及运行稳定性是当前厌氧生物技术中亟待解决的关键问题。对厌氧生物处理理论的深入研究，是开发新技术和进一步提高系统处理效能和运行稳定性的基础。有机负荷率（OLR）和pH是厌氧生物处理系统的重要运行控制参数，其变化会对系统中微生物群落结构产生显著影响并进一步影响到系统的处理效能。研究厌氧生物处理系统中HPAs对有机负荷率（OLR）和pH的生态响应规律，揭示HPAs的动态变化与系统运行特征之间的内在联系，探索强化厌氧生物处理系统中产氢产乙酸作用的调控对策，对于进一步提高厌氧生物处理系统的运行效能及稳定性具有重要意义。本文选取UASB和ABR两种典型厌氧反应器为实验装置，以UASB和ABR的启动和运行为基础，分别考察了OLR和pH的变化对UASB和ABR运行效能及稳定性的影响，并采用聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）指纹分析技术对系统中HPAs的演替规律进行解析。在此基础上，探讨UASB和ABR系统中HPAs演替与系统运行特征之间的内在联系，提出强化厌氧生物处理系统中产氢产乙酸作用的调控对策。根据UASB和ABR的构造及工艺特点，分别采用不同的启动方式对反应器进行启动。UASB采用“固定进水COD浓度，分阶段缩短水力停留时间（HRT）”的方式启动，经过180d的连续运行，在进水COD1000mg/L、HRT8h的条件下达到运行稳定，系统的COD去除率维持在90%以上，反应区出现大量成熟颗粒污泥。ABR采用低负荷启动方式进行启动，经过228天连续运行，在进水COD8000mg/L、HRT36h、OLR5.4kg COD/m~3·d的条件下达到稳定运行，产酸相和产甲烷相沿程得以有效分离。第1格室和第2格室以产酸发酵菌群为优势菌，为产酸相；而在第3格室和第4格室中HPAs和产甲烷菌占据优势地位，为产甲烷相。在UASB和ABR启动完成的基础上，研究了HPAs对OLR变化的生态响应规律。结果表明，随着OLR的逐步提升，UASB和ABR系统中HPAs发生了明显的演替过程。在OLR比较低（<10kg COD/m~3·d）时，具有较低最大比降解速率（Umax）和比生长速率（μ）的食丙酸产氢产乙酸菌Syntrophobacterwolinii为优势菌。而随着OLR的提升，具有较高Umax和μ的食丙酸产氢产乙酸菌Pelotomaculum propionicicum和P. schinkii依次演替成为系统中的优势菌。HPAs的演替强化了系统中的产氢产乙酸作用，使得UASB和ABR系统的处理效能得到显著提高。在UASB和ABR系统中，随着OLR大幅提升，系统的COD去除率均保持在92%以上。因此，在废水厌氧生物处理工程中，在反应器的启动期和稳定运行期，可通过人为的、定期的“制造”OLR冲击，促使反应器中HPAs发生演替，以此来强化系统中HPAs的产氢产乙酸作用，将有利于厌氧生物处理系统的长期稳定运行。在UASB系统中，pH的降低对HPAs的分布和优势度产生了显著影响，食丙酸产氢产乙酸菌Pelotomaculum schinkii在系统中的优势度随着系统内pH的下降而显著降低。而P. schinkii优势度的降低，导致UASB系统的COD去除率由91%下降到了68%，出水中丙酸残留增加到了1250mg/L。在UASB系统中，当pH为限制性生态因子时，HPAs的产氢产乙酸作用对厌氧生物处理过程的限制作用要大于产甲烷菌群。因此，在UASB的运行调控过程中，不仅要考虑产甲烷菌的生理生态特性，更要优先考虑HPAs的生理生态特性。ABR系统对pH的下降具有良好的缓冲性能，当进水pH由8.0逐级下降到6.0时，ABR系统整体的COD去除率均保持在93%以上。ABR良好的缓冲性能来自系统中主要功能菌群对pH下降的积极生态响应。当pH作为限制性生态因子时，进水pH的下降会使ABR系统产酸相的发酵类型发生转变，进而促进系统中HPAs的演替。在废水厌氧处理工程中，可通过对进水pH的调控，将ABR系统的产酸相控制在乙醇型发酵，为HPAs提供最适宜的底物，使得系统中的产氢产乙酸作用得以强化，进而提高系统的处理效能及运行稳定性。将ABR系统的产酸相控制在乙醇型发酵，在提高系统的处理效能及运行稳定性的同时，还可以实现同步产氢产甲烷。更多还原

【Abstract】 Environmental pollution and the energy crisis are two problems that plaguedthe sustainable socio-economic development and human survival. Anaerobicbiotechnology has become an important route to solve environmental pollution andenergy shortage. How to enhance the efficiency and the stability of anaerobicbiotechnology are the key issues to be solved in the current. The study of anaerobicbiological theory is foundation to develop new technology and impove theefficiency and stability of anaerobic reactors. Organic load rate (OLR) and pH werevery important operation control parameters of anaerobic reactors, and whichchanges will impact on microbial community structure and furth affect theefficiency of anaerobic treatment systems. So it is the crucial for enhancing theefficiency and the stability of anaerobic digesters by strengthening function ofHPAs. While the response characteristics of HPAs to organic loading rate (OLR)and pH was basis to strengthen function of HPAs in digestors.An upflow anaerobic sludge blanket (UASB) reactor and an anaerobic baffledreactor (ABR) were chose. The impact of OLR and pH on performance of reactorswere investigated, respectively. The succession of HPAs was detected bypolymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE).On this basis, the intrinsic link between the HPAs succession and performance ofUASB and ABR was discussed, and then put forward the strategy of strengtheningHPAs. The study will lay the foundation of development high rate anaerobictreatment technology by strengthening HPAs.According to the structure and process characteristics of UASB and ABR, thereactors were started in different ways. UASB was started by fixing influent CODconcentration and phased shortening of hydraulic retention time (HRT).A steadystate was achieved with an influent COD1000mg/L and HRT8h after180dcontinuously running, a COD removal rate of90%was obtained and anaerobicgranular sludge was cultivated successfully. ABR was started at lower OLR, asteady state was obtained with an influent COD8000mg/L, HRT36h and OLR5.4kg COD/m~3·d after228d continuously running, and microbial-phase separationwas achieved in the ABR. The acidogenic phase was formed in the first twocompartments, while the methanogenic phase was formed in the last twocompartments. Thus, microbial-phase separation laid a foundation for performingsteady and pollutant removal effectively in the ABR.Response of HPAs on OLR change was investigated after start-up of UASB and ABR systems. The results showed that HPAs succesion was obvious with OLRincrease in these two bioreactors. Under low OLR condition (<10kg COD/m~3·d),Syntrophobacter wolinii (HPAs) with low specific maximum degradation rate (Umax)and specific maximum growth rate (μ) was the dominant HPAs. With OLR increase,Pelotomaculum propionicicum and P. schinkii with high Umaxand μ was thedominant HPAs in turn. Succession of HPAs inhanced the hydrogen-producingacetogenesis in systems, resulting in treatment efficiency of UASB and ABR wassignificiantly improved with COD removal of above92%during the OLRincreasing. During the wastewater anaerobic biological treatment process, therefore,periodical OLR shocks could promote HPAs succession and improvehydrogen-producing acetogenesis for long-term stable operation of an anaerobicsystem.In UASB, the distribution and dominance of HPAs were significantly affectedby pH reduction. The dominance of Pelotomaculum schinkii in the reactor wasobviously decreased with pH reduction, resulting in COD removal was deceased to68%from90%with propionate1250mg/L. These results indicated that thehydrogen-producing acetogenesis was the rate-limiting step in UASB when pH wasthe restrictive ecological factor. Therefore, not only methanogens should beenhanced but also HPAs should be enhanced during the operation and regulation ofUASB.ABR had a favourable buffer performance to pH reduction. COD removal ofABR was above93%at pH8.0~6.0in influent. A good buffer performance of ABRdepends on the positive response of major functional community on pH reduction.Reduction of influent pH made fermentation type in acidogenic phase was changedand then promoted HPAs succession. In wastewater anaerobic biological treatmentprocess, fermentation type in acidogenic phase could be regulated as ethanol-typefermentation by adjusting influent pH. Ethanol-type permentation would supplyoptimum substrate for HPAs, leading to a high efficiency hydrogen-producingacetogenesis and then improving the performance of anaerobic biological treatmentsystems. In addition, synchronous hygrogen methane-production in ABR would become true if the acidogenic phase was controled as ethanol-type permentation.更多还原