【作者】 王克浩；

【导师】 李东伟；

【作者基本信息】 重庆大学 ， 环境工程， 2007， 硕士

【摘要】 70年代初,Ghosh和Pohland根据厌氧生物分解机理和微生物类群的理论首先提出了两相厌氧消化的概念:将产酸菌和产甲烷菌分别置于两个串联的反应器内并提供各自所需的最佳条件,使这两类细菌群都能发挥最大的活性,提高反应器的处理效率。这两个串联的反应器分别称为产酸反应器(产酸相)和产甲烷反应器(产甲烷相)。本课题针对实验设计的两相厌氧反应器进行启动和分相研究,寻求快速启动的方法、研究分相效果。试验采用人工配水,以淀粉、葡萄糖作为主要的碳源,两相均为UASB反应器。采用低负荷启动方式,快速提高进水COD,缩短水力停留时间,使产酸相尽快保持在酸性条件下。间歇投加粉末CaO调节产酸相出水pH值在7.0±0.3范围内,从而保证产甲烷相在最佳条件下。经过36d的启动过程,产酸反应器和产甲烷反应器中粒径>1.0mm的颗粒污泥分别占69%和64%。启动第36d,两相厌氧反应器停留时间为17.03h,容积负荷为8.46kgCOD/(m3·d),水力负荷0.059(m3/m2·h)时,系统整体COD去除率达到最优,为96.66%。其中,产酸相HRT为5.42h,VLR为27.32kgCOD/(m3·d),水力负荷为0.195m3/m2·h,去除率30.21%;产甲烷相HRT为11.61h,VLR为8.90kgCOD/(m3·d),水力负荷为0.091m3/m2·h,去除率为95.21%。实现了两相厌氧反应器成功启动。产酸UASB中的微生物主要为水解产酸杆菌,并含有有少量球菌。产甲烷UASB中主要为产甲烷球菌和八叠球菌,并伴有少量螺旋状菌。通过对反应器中颗粒污泥及微生物观察研究,认为本实验中颗粒污泥的形成过程分为不规则核心、挤压架桥、分割成长、修剪长大四个阶段。此外,加速污泥颗粒化的因素有适宜的生长环境、配水、良好的水力特征等。分相实验中选择钼酸钠(Na2MoO4)作为抑制剂,投加浓度为2.0mmol/L。投加钼酸盐后,产酸反应器出水COD比正常条件下出水增大。停止投加之后,产酸反应器出水逐渐稳定在4500mg/L左右,去除率由原来26%～34%降低到23%～27%。投加钼酸盐使产酸相酸化率提高到60%以上,产甲烷相出水水质进一步提高。钼酸盐对产甲烷菌的杀灭作用是不可恢复性的,很好的实现了对产酸反应器中产甲烷菌的杀灭作用,实现了产酸相中的完全分相。分相实验期间,产酸颗粒污泥外表为灰白色,内部为黑色。颗粒粒径越大,形状越不规则,质地松散,多为椭圆形。外表不光滑,部分粒径在3.0mm以上颗粒污泥开始破裂。更多还原

【Abstract】 At the beginning of the 70th, Ghosh and Pohland firstly proposed the concept of two-phase anaerobic according to the anaerobic biological digestion mechanism and the microorganism group theory. Acid-formers and methane-formers were physically separated in two reactors, where optimum environmental conditions for each group of organisms would be provided to enhance the overall process stability and control. Two reactors in series were respectively acidogenic reactor (acidogenic phase) and methanogenic reactor (methanogenic phase).In this paper, the start-up and phase-separation of two-phase anaerobic reactor designed for experiment were investigated, so to seek the rapid start-up method and to study the effect of phase-separation. Glucose and starch were used as the organic-carbon source of the synthetic wastewater in this study. Two phases were both UASB reactors. Starting up at low organic loading, the influent COD was increased quickly and HRT was shortened, so that acidogenic phase could work in acidic condition as soon as quickly. Pulverous Ca(OH)2 was added intermittently into acidogenic phase to keep the effluent pH 7.0±0.3, so that methanogenic phase could work in optimal condition. After 36 days of operation, Respectively 69% and 64% of total bioparticles were more than 1.0mm in acidogenic reactor and methanogenic one. On the 36ed day, two-phase anaerobic system was achieved optimal COD removal efficiency (96.66%) at HRT of 17.03h and VLR of 8.46kgCOD/(m3·d) and hydraulic surface loading of 0.059(m3/m2·h), when HRT, VLR, hydraulic surface loading and COD removal efficiency were respectively 5.42h, 27.32kgCOD/(m3·d), 0.195m3/m2·h, 30.21% in acidogenic phase, and 11.61h, 8.90kgCOD/(m3·d), 0.091m3/m2·h, 95.21% in methanogenic phase. So two-phase anaerobic reactor achieved rapid start-up successfully.The microorganism in acidogenic UASB was mainly bacilli and a few cocci, which in methanogenic UASB was mainly Methanococcus and Methanosarcina. After the investigation of granular sludge and microorganism in reactors, it was believed that the granular sludge was shaped through irregular core, extrusion and bridging, division and growth, shear and accretion.Sodium molybdate was included in the feed as the inhibitor in the phase-separation experiment. The concentration of MoO42- was 2.0mmol/L.After the addition of MoO42-, the effluent COD in acidogenic reactor was increased. After MoO42- was omitted from the feed, the effluent COD of acidogenic phase was finally about 4500mg/L.The COD efficiency decreased from 26%～34% before to 23%～27%。Acidfication rate in acidogenic phase increased to 60% above by molybdate addition. The effluent of methanogenic phase was improved. For that the MoO42- was bacteriocidal to MPBs which did not recover, it could be used to kill the MPBs and achieved nearly complete phase separation in in acidogenic phase. During the phase-separation experiment period, the appearance of the granular sludge in acidogenic phase was hoar out and black in. As the granular was bigger, the shape was more irregular, the texture was more incompact. The granular sludge was ellipse and rough. The granular sludge above 3.0mm in diameter began to break.更多还原