【作者】 王春；

【导师】 王晓昌；

【作者基本信息】 西安建筑科技大学 ， 环境科学， 2009， 硕士

【摘要】 好氧颗粒污泥由于其密实的结构、良好的沉淀性能及较好的水处理效果已引起广泛的关注。好氧颗粒污泥作为近期发展起来的一种特殊的生物膜工艺,它的形成也是一种自我固定的生物过程,其胞外物质EPS在该过程中起着非常重要的作用。本研究以西安市邓家村污水处理厂二沉池回流污泥做为接种污泥,在四个相同的序批式反应器(SBR)内和不同条件下培养形成好氧颗粒污泥。通过考察污泥颗粒化的过程,研究了在不同负荷及盐度条件下,好氧颗粒污泥的形成过程及其物理特性。同时结合比耗氧速率(SOUR)、孔隙率和生物处理效果对好氧颗粒污泥的EPS特性做了进一步的探索。结果表明:(1)在SBR反应器中形成的好氧颗粒污泥,其物理特性——颗粒沉速、颗粒密度、SVI,与进水有机负荷、含盐量高低无绝对的相关性,但进水有机负荷对其物理特性有明显的影响;此外,相对于含盐量,负荷对好氧颗粒污泥EPS的变化影响更大。推测其原因可能是由于微生物在逐步调整含盐量过程中已经被驯化,而被驯化的微生物种群的差异性主要取决于有机负荷;(2)低负荷低含盐条件下,细胞主要通过胞外多聚物的架桥作用而连接在一起,从而形成了颗粒污泥。而在高负荷高含盐量条件下,颗粒主要是以丝状菌的相互缠绕作为骨架而形成的;(3)试验结果表明:好氧颗粒污泥中EPS糖和SOUR之间、EPS蛋白和孔隙率之间均呈负相关;(4)通过研究,我们发现含盐量为2.5%条件下颗粒污泥容易发生解体,推测其解体的原因主要是在低负荷低含盐条件下由于所分泌的胞外多聚物较多,使得颗粒外围比较松散,并且易堵塞传质通道,从而内部微生物易发生水解,导致颗粒空洞的形成;另外该条件下丝状菌未能成为优势菌群而大量繁殖,因此不能形成颗粒所需骨架。更多还原

【Abstract】 Aerobic granules have received extensive attention because of its compact structure,good sedimentation and effecicency for wastewater treatment.The aerobic granules could be considered as one of the biofilm process,the formation of which is also a process of self-immobilization,and thus the extracellular polymeric substances(EPS) play an important role,which is scope of this study.The seed sludge in this sludge was taken from with returning activated sludge line from a secondary settling tank in a wastewter treatment plant.Four identical sequencing batch reactors(SBRs) were used in this study with different operational conditions.The granualtion process and its phycochemical properties of aerobic granules were examined under different organic loading rates(OLRs) and salinities. Especially,the characteristics of EPS and its relationship between specific oxygen uptake rate(SOUR),porosity and biological treatment effeciencis were investigated.The results showed that:(1) The physical properties of aerobic granules,i.e., settling velocity,density and SVI had inconsiderable correlation with salinities,but had considerable correlation with OLRs;Addtionally,the OLRs affected the EPS more than the salinities,which could be explained that microorganisms in the reactors had became accustomed to different salinities during the gradually change period of salinities;(2) It was assumed that under the conditions of a low OLR and salinity,the formation of the aerobic granules was mainly due to the interlinkage of EPS,and those of high influent OLR and salinity,the framework formed by filaments accounted for the formation of the aerobic granules;(3) The experiment found two negative correlations in the aerobic granules:one was between EPS carbohydrate and SOUR,and the other was between EPS protein and porosity;(4) Aerobic granules formed under the salinity of 2.5%was prone to disintergration.更多还原