好氧颗粒污泥的培养及其实现同步硝化反硝化的研究

【作者】 杨麒；

【导师】 李小明； 曾光明；

【作者基本信息】 湖南大学 ， 环境工程， 2003， 硕士

【摘要】 传统的废水生物处理工艺多以含碳有机物和悬浮固体为主要处理目标，而对废水中的氮、磷等营养物质的去除重视不够。据统计，我国目前城市污水处理率仅有5％左右，且绝大多数城市污水处理厂不具备脱氮除磷的能力。过多的氮、磷化合物进入天然水体不仅使得水环境质量恶化，影响渔业、旅游业、养殖业的发展，而且还对人体健康以及动、植物的生存产生严重的危害。因此，无论是从国际发展趋势来看，还是我国现实水污染状况出发，控制水体的富营养化，研究污水脱氮，探索适合我国国情且经济有效的脱氮工艺和方法，已成为亟待开展的研究课题。 本课题立足于国内外生物脱氮研究的最新研究成果，改变传统的研究思路，从单纯的革新处理工艺方法解决同步生物脱氮过程中矛盾关系的研究方向转变到培养高活性具有生物脱氮能力的好氧颗粒污泥。实验通过对SBR反应系统中COD／NH_3-N比、溶解氧、酸碱度等运行条件进行调控，培养具有同步硝化反硝化脱氮，兼有高效去除有机物能力的好氧颗粒污泥，对其形成机理进行初步探讨，并对其实现同步硝化反硝化作初步研究。 实验结果表明通过对运行过程的有效调控和污泥的定向驯化，经过约2个月的培养，在SBR反应器内活性污泥凝聚成团，形成了高活性且具有良好同步硝化反硝化能力好氧颗粒。好氧颗粒污泥外观呈橙黄色，表面光滑，近似圆形或椭圆形，粒径一般为0.5～1.0mm，粒度分析结果表明粒径在1.0mm左右的颗粒占全部污泥颗粒的20％以上。颗粒污泥浓度MLSS达到10g/L左右，沉降指数SVI约32.5mL／g，沉降速度约在25～40m／h之间，沉降性能良好，其有效生物量远远高于一般的好氧活性污泥。 实验中在进水碳氮比为6，反应器内DO为3mg／L的条件下，COD和NH₃-N的去除率分别在83.6％～92.8％和82.3％～98.5％之间，同时出水中NO₃^--N、NO₂^--N浓度均维持在低于1mg／L的范围内，说明存在好氧颗粒污泥的SBR反应器内发生 的是同步硝化反硝化反应，而不是一般活性污泥SBR反应器内发生的顺序式硝化 反硝化反应。 好氧颗粒污泥具有良好的水力强度，相对较高的容积负荷，良好的沉降性能， 并不需要额外的沉淀系统。对模拟生活污水中氮及COD很好的去除效果，显示出 好氧污泥颗粒化技术具有良好的应用前景。更多还原

【Abstract】 For recent decades, especially in China, the main objective for wastewater biological treatment by conventional technology was only to remove organic materials containing carbon compounds and suspended solids, less attentions were paid to removal of other nutritious substances such as nitrogen, phosphorus. According to the statistics, only about 5 percent of the municipal wastewater at present in China was treated, few of which had been dealt with nitrogen and phosphorus. The entrances of overmuch nitrogen and/or phosphorus compounds to natural water bodies not only made the quality of water environment deteriorated and affected the development of fish culture, tour industry and poultry raising, but also seriously harmed human health and the survival of animal and plant.With the development of water pollution control both internationally and domestically, it had become a hotspot to do the research on how to control the water bodies eutrophication caused by nitrogen and phosphorus, and how to remove efficiently the nitrogen and phosphorus as well as how to develop a special technics used for nitrogen and phosphorus removal, which were suitable to the situation of our country, economically and effectively.Based on the latest research findings on biological nitrogen removal in both domestic and abroad, this research changed the traditional idea from solving the ambivalent relationship in simultaneous biological nitrogen removal course by simply reforming the treatment techniques to focusing on cultivation of aerobic granular sludge capable of removing simultaneously and efficiently nitrogen and organic materials in Sequencing Batch Reactor (SBR) by controlling the operation conditions such as the ratio of COD to NH/-N, dissolved oxygen (DO), alkalinity acidity, and exploring basically the formation mechanism of it as well as its’ behavior of simultaneous nitrification and denitrification.The experimental results showed that aerobic granular sludge with high activity of simultaneous nitrification and denitrification could be formed in around 2 months by effectively controlling the operation cycle and purposefully cultivation in SBR with inoculation of normal activated sludge from municipal wastewater treatment plant. Aerobic granular sludge formed with averagely 0.5-1.0 mm in diameter and well settle-ability (the sedimentation rate is between 25m/s and 40 m/s) appeared in orange yellow, smooth and approximate roundness or ellipse, and the results ofparticle-dimension analysis showed that above 20 percent of granules were about 1 .0mm in diameter. The Mixed Liquid Suspended Solids (MLSS) and the Sludge Volumetric Index (SVI) of the granular sludge system were above 4.5g/L and about 32.5, respectively, which indicated a higher concentration of effective biomass than normal aerobic activated sludge process.With the ratio of carbon to nitrogen in influent 6 and the DO in the reactor less than 3mg/L, the removal rates of COD and NH3-N reached 83.6%~92.8% and 82.3%~98.5%, respectively, in the aerobic granules SBR system, and in the meantime the concentration of NO3--N, NO2--N in effluent were all under Img/L, which shown that simultaneous nitrification and denitrification (SND) rather than sequential nitrification and denitrfication (SQND) occurred in the aerobic granular sludge SBR.With the advantages in high water shear intension and volumetric loading capacity,well settling performance and unnecessary clarifier system, as well as a high efficiency in nitrogen and COD removal for the synthetic domestic wastewater, a good application perspective of the aerobic granulation system could be predicted.更多还原