【作者】 黄宇；

【导师】 赵林；

【作者基本信息】 天津大学 ， 环境科学， 2010， 博士

【摘要】 磷是引起水体富营养化的重要因素,同时也是一种日益匮乏的不可再生资源,因此,从含磷污水中去除并回收磷是实现磷资源可持续利用的良策。本文将好氧颗粒污泥技术应用到污水强化生物除磷(EBPR)工艺中,控制低有机负荷率,按照EBPR工艺的运行方式,成功培养出一种以聚磷菌为主体的聚磷好氧颗粒污泥。与传统EBPR工艺相比,形成的聚磷好氧颗粒污泥能够实现很好的除磷性能,具有含磷量高和沉降性能好等优点,并证实采用低有机负荷率适合作为聚磷好氧颗粒污泥的培养策略。采用较低的有机负荷率会降低微生物的生长速率,从而增加反应器的启动时间,为了弥补这一不足,本文研究了聚磷好氧颗粒污泥的储存及活性恢复特性,考察以成熟的聚磷好氧颗粒污泥作为接种污泥来缩短反应器启动时间的可行性。实验结果表明聚磷好氧颗粒污泥独特的颗粒结构使其具有良好的储存性能,经过2个月的储存,能够维持颗粒结构的完整性,重新启动后可以迅速恢复原有的颗粒特性和除磷性能,并证实低温密封更适合聚磷好氧颗粒污泥的储存。研究了碳源种类等因素对聚磷好氧颗粒污泥厌氧释磷能力的影响,确定了乙酸钠为碳源,温度为25℃和pH=7~8时最适合污泥厌氧释放磷酸盐。实验结果表明在碳源不足时硝酸盐的存在会抑制污泥厌氧释磷,这主要是由反硝化与释磷反应的底物竞争所导致。实验过程中发现柠檬酸钠对聚磷好氧颗粒污泥厌氧释磷有促进作用,通过考察柠檬酸钠对ED途径和EMP途径的关键酶活性的影响,证实柠檬酸钠可以通过调节糖原降解途径从而促进磷酸盐的释放。热处理也是一种能够使污泥释放磷酸盐的有效方法,考察了不同的热处理温度下聚磷好氧颗粒污泥的磷、碳、氮的释放特性。通过对比厌氧释磷和热处理释磷两种方法各自的优缺点,提出了一种将这两种污泥释磷方法相结合的污泥厌氧-热处理集成工艺,将热处理过程中释放的有机物作为厌氧释磷所必需的碳源,可以降低厌氧释磷添加药剂的成本,以及污泥热处理后有机物的排放量。基于稳定运行状态下各物质的质量平衡关系,建立了该工艺的数学模型,并通过批次实验确定了各工艺参数。按照已确定的工艺参数,研究了该工艺的实际运行性能,结果表明该工艺可以使污泥释放出59%的磷用于回收,处理后的污泥质量降低了37.7%,与单独应用热处理释磷方法相比有机物排放量降低了43.5%。更多还原

【Abstract】 Phosphorus is one of the most common pollutants that could cause water eutrophication. Meanwhile, phosphorus is also a kind of unsustainable and increasing shortage resources. Therefore, phosphorus recovery from wastewater is a meaningful strategy in order to realize phosphorus sustainable utilization.The technology of aerobic granular sludge was applied to enhanced biological phosphorus removal (EBPR) process from wastewater in this study. Phosphate-accumulating aerobic granules dominated by phosphate accumulating organisms (PAOs) were achieved in EBPR process operated under low organic loading rate. The cultured aerobic granules present good phosphorus removal performance and have numerous advantages such as higher phosphorus content and better settleability as compared to conventional activated sludge flocs in EBPR process. This result proved that aerobic granules could be obtained by controlling low organic loading rate.Low organic loading rate could decrease the microbial growth rate and increase the start-up time of the biological water treatment process. The influence of two-month storage under different conditions on the storage and subsequent reactivation performance of aerobic granules was investigated in order to validate the possibility that using cultured mature aerobic granules as seed sludge to speed up the formation of aerobic granules and reduce the start-up time. A specific inner rod-shaped bacteria aggregate tightly wrapped by filamentous bacteria structure provides phosphate-accumulating aerobic granules excellent storage performance. After two months storage, aerobic granules could maintain their structure integrity and quickly restored their original granular characteristics and phosphate removal ability. It was confirmed that low temperature and anaerobic storage conserve the structure integrity during storage and promote the reviving behaviors of phosphate-accumulating aerobic granules during reactivation.Effects of some parameters such as kinds of carbon resource etc. on phosphate-releasing performance of phosphate-accumulating aerobic granules were investigated. The optimal phosphate-releasing conditions were sodium acetic as carbon resource, 25℃and pH=7~8. The results suggested that the existence of nitrate could inhibit phosphate release of phosphate-accumulating aerobic granules when the carbon resource sodium acetic was deficient, which was due to the competition to the carbon resource between denitrification process and phosphate release process. It was discovered that sodium citrate could enhance the phosphate release of phosphate-accumulating aerobic granules. The influences of sodium citrate on the key enzymes’activities involving in ED and EMP pathway were investigated and the result confirmed that sodium citrate could enhance the phosphate release through mediating the metabolic pathway of glycogen.Heat treatment to sludge is an effective phosphate-releasing way. The phosphate, carbon and nitrogen release properties of phosphate-accumulating aerobic granules were investigated under different temperature. A combinative phosphate recovery process of heat treatment and anaerobic phosphate release was proposed by comparing their advantages and disadvantages. The organics released by the granules during heat treatment were used as the carbon resource for the granules during anaerobic phosphate release process, which decreased not only the cost of carbon resource addition during anaerobic phosphate release process but also the organics discharge after heat treatment. A steady model for this proposed phosphate recovery process was established based on the mass balance relationship and the model parameters were experimentally confirmed. The proposed phosphate recovery process was conducted to investigate the phosphate recovery performance. The results suggested that via this phosphate recovery process 59% phosphate released by the granules could be used for recovery, the mass of sludge discharge decreased 37.7% and the organics discharge decreased 43.5% as compared to that only via heat treatment.更多还原