分段进水的生物除磷脱氮工艺

系统阐述了分段进水的生物除磷脱氮新工艺的发展情况、工艺特性和应用前景，结合工程实例介绍了该工艺的处理效果并对一些问题作了探讨。     

Carrousel氧化沟脱氮除磷工艺的运行控制

根据江门市文昌沙水质净化厂的运行经验，探讨了脱氮除磷的Carrousel氧化沟工艺在进水混合液配比、回流比、MLSS、泥龄、DO等工艺参数方面的调整控制，并总结了较佳的脱氮除磷运行方式。     

MBR组合工艺脱氮除磷研究进展

常规MBR工艺处理城市生活污水尽管可以获得较低SS的出水,但对氮、磷的去除却很难达到愈来愈严格的排放要求,因此强化MBR工艺生物段的脱氮除磷功能成为目前研究的热点问题。分析了MBR脱氮除磷的潜力,介绍了各种MBR组合工艺脱氮除磷的原理、特点及处理效果,探讨了MBR组合工艺脱氮除磷的研究方向,认为微生物学机理、强化内源反硝化及膜污染控制等是其研究重点。     

氧化沟工艺脱氮除磷研究现状

目前,氧化沟工艺已成为国内外污水处理厂的主流工艺,但对于该工艺的系统研究并不多,在生物处理理论方面,同步硝化反硝化和反硝化除磷备受关注,因此对氧化沟工艺进行该方面的研究更具现实意义。     

污泥回流比对A_2N反硝化除磷工艺脱氮除磷的影响

以城市生活污水为研究对象,探讨了不同的超越污泥和回流污泥回流比对A2N工艺脱氮除磷的影响.在超越污泥回流比与回流污泥回流比相同且分别为0.3、0.4和0.6的条件下,A2N工艺对COD的平均去除率分别为92.5%、90.3%、91.6%,相应的出水COD为20.3、28.4、25.3 mg/L;对总氮的平均去除率分别为87.1%、90%、84.9%,出水总氮分别为6.75、5.43、6.95mg/L;对磷的平均去除率分别为99.5%、99.6%和99.0%,出水磷浓度分别为0.02、0.02、0.05mg/L.当回流比为0.4时,A2N系统的除污效果最好.研究还发现,超越污泥流量直接决定了未经硝化而直接进入缺氧池的氨氮量,进而影响出水氨氮浓度.因此,在保证缺氧池有足够污泥的前提下,应尽可能减小超越污泥流量,以降低出水氨氮浓度.     

SBR工艺脱氮除磷研究进展

概述了SBR脱氮工艺中的同步硝化/反硝化，亚硝化脱氮现象，讨论了影响SBR除磷的碳源，聚磷菌与非聚磷菌竞争，pH值，好氧曝气，污泥龄，水力停留时间等因素，并对SBR工艺中脱氮与去除之间的相互影响进行了探讨，最后给出了可以同时脱氮除磷的一种SBR运行方式。     

DO对A/O同步脱氮除磷工艺的影响研究

采用A/O同步脱氮除磷工艺处理模拟城市污水,考察了好氧段DO浓度对该工艺处理效果的影响.结果表明,好氧段DO浓度对系统脱氮除磷效果的影响显著,当DO控制在1.5mg/L左右时,系统的处理效果最佳,可实现同步硝化反硝化和反硝化除磷,对NH4+-N、TN、TP、COD的去除率分别为99.12%、94.61%、92.85%、96.10%,平均出水NH4+-N、TN、TP、COD分别为0.25、0.68、0.5和10 mg/L.     

移动床生物膜反硝化脱氮除磷工艺

1 工艺过程简介 瑞典马尔墨赫隆德(Sjolunda)污水处理厂为满足新的出水水质标准将对原有工艺流程进行改造,污水处理厂服务人口55万人,处理规模15万t/d。该厂自1974年全部建成投产以来为三级处理,生化处理工艺为两个并行的系列:一个是活性污泥曝气池工艺,另一个为生物滤池工艺,两系列处理能力相同。三级处理为气浮法工艺。污泥处理部分包括浓缩、厌氧硝化和脱水过程(附图1)。     

污泥龄对BBSNP工艺反硝化除磷脱氮效能的影响

基于上海某污水处理厂的生产性试验装置,研究了污泥龄(SRT)对两级生物选择反硝化除磷脱氮(BBSNP)工艺反硝化除磷效能的影响。结果表明,SRT对BBSNP工艺的反硝化除磷效能有着较大的影响。当将SRT从7 d提高到15 d时,厌氧区的COD去除率由62.37%提高到80.32%;缺氧吸磷率均值由33.9%提高到77.9%,厌氧释磷倍数由3.11倍提高到4.13倍;总氮去除率由68.27%提高到74.05%,这表明系统内富集了大量的反硝化聚磷菌,表现出良好的反硝化除磷效果,提高了出水水质。     

污水反硝化脱氮除磷新工艺研究进展

反硝化脱氮除磷新技术以其能耗低、投资小和运行费用低等优点,得到越来越多的应用.介绍了反硝化脱氮除磷的机理和特点,分析了几种常见的反硝化脱氮除磷新工艺,结合反硝化脱氮除磷技术研究现状提出了今后工艺研究中有待解决和完善的问题.     

Enhanced nutrient removal by biological treatment systems

The importance of nitrogen and phosphorus in stimulating eutrophic conditions in receiving waters has been well documented. As a result, over the last decade an increased emphasis has been placed on limiting these elements in wastewater effluents. In the future, new discharge permits will include limits on both of these elements.

In 1985 a research program was initiated to conduct a pilot plant study of an anoxic/anaerobic/aerobic treatment train using primary effluent. The facility was operated at varying flow and Qr/Q ratios, and at effective mixed liquor suspended solids (MLSS) concentrations of 3100 mg/L. The results of the first 13 month operational phase indicated that the effluent concentrations of total BOD₅, TSS and nitrate nitrogen were less than 5 mg/L. Ammonia nitrogen was less than 0.2 mg/L. The solids settleability was excellent, and foaming due to Norcadia, was effectively controlled. The average overall phosphorus removal was 48%. Influent BOD₅ concentrations of less than 100 mg/L significantly reduced the system's ability to remove phosphorus. A strong relationship between the amount of carbon source in the influent, phosphorus release in the anoxic and anaerobic tanks and phosphorus uptake in the aeration basin was established.     

Characterization of dairy waste streams, current treatment practices, and potential for biological nutrient removal

Fifteen milk processing plants in the Upper Midwest of the United States participated in a study to obtain information on general process operation, waste generation and treatment practices, chemical usage, and wastewater characteristics. Long term data on wastewater characteristics were obtained for 8 of the 15 dairy plants, and a 24-h composite wastewater sample was characterized in detail for each plant. Wastewater flow rates and characteristics varied greatly among and within plants and were not easily predictable even when detailed information on processing operations was available. In addition, the contribution of milk and milk products to the waste streams was underestimated by plant operators. The use of caustic soda, phosphoric acid, and nitric acid for cleaning had a significant impact on wastewater characteristics, despite the implementation of changes in chemical usage practices during recent years. In particular, the use of phosphoric acid based cleaning products has been reduced to eliminate or decrease discharge fines. It was determined that most of the on site treatment facilities require renovations and/or operational changes to comply with current and future discharge regulations, especially with respect to nutrient (nitrogen and phosphorus) levels in their waste streams. It was concluded that biological nutrient removal of dairy wastewaters should be feasible given the relatively high concentrations of easily degradable organics, the generally favorable organic matter to total phosphorus ratio, and the very favorable organic matter to nitrogen ratio.     

生物法除磷的研究进展

叙述了生物法利用聚磷菌和反硝化聚磷菌除磷原理,研究了不同运行方式、有机物浓度及其种类、厌氧段NO3-浓度和污泥龄等因素对生物除磷产生的影响,并指出现阶段生物除磷存在的问题,以期对生物除磷的试验和实际生产提供帮助。     

Advancing post-anoxic denitrification for biological nutrient removal

The objective of this research was to advance a fundamental understanding of a unique post-anoxic denitrification process for achieving biological nutrient removal (BNR), with an emphasis on elucidating the impacts of surface oxygen transfer (SOT), variable process loadings, and bioreactor operational conditions on nitrogen and phosphorus removal. Two sequencing batch reactors (SBRs) were operated in an anaerobic/aerobic/anoxic mode for over 250 days and fed real municipal wastewater. One SBR was operated with a headspace open to the atmosphere, while the other had a covered liquid surface to prevent surface oxygen transfer. Process performance was assessed for mixed volatile fatty acid (VFA) and acetate-dominated substrate, as well as daily/seasonal variance in influent phosphorus and ammonia loadings. Results demonstrated that post-anoxic BNR can achieve near-complete (>99%) inorganic nitrogen and phosphorus removal, with soluble effluent concentrations less than 1.0 mgN L⁻¹ and 0.14 mgP L⁻¹. Observed specific denitrification rates were in excess of typical endogenous values and exhibited a linear dependence on the glycogen concentration in the biomass. Preventing SOT improved nitrogen removal but had little impact on phosphorus removal under normal loading conditions. However, during periods of low influent ammonia, the covered reactor maintained phosphorus removal performance and showed a greater relative abundance of polyphosphate accumulating organisms (PAOs) as evidenced by quantitative real-time PCR (qPCR). While GAOs were detected in both reactors under all operational conditions, BNR performance was not adversely impacted. Finally, secondary phosphorus release during the post-anoxic period was minimal and only occurred if nitrate/nitrite were depleted post-anoxically.     

Modelling biological nutrient removal activated sludge systems - a review

The external nitrification (EN) biological nutrient removal (BNR) activated sludge (ENBNRAS) system shows considerable promise for full-scale implementation. As an aid for this implementation, a mathematical simulation model would be an invaluable tool. To develop such a model, a study was conducted to select the most suitable simulation model to serve as a starting point for further development. For this, the existing available simulation models for BNRAS systems are compared with one another and evaluated against experimental observations in the literature and on ENBNRAS systems. One process immediately apparent to be crucially important is the anoxic growth of phosphorus accumulating organisms (PAOs), with associated PAO denitrification and anoxic P uptake for polyP formation. These linked processes are lacking in the earlier kinetic simulation models for BNRAS systems, which were based on aerobic PAO growth and P uptake only, but have been incorporated into the more recent kinetic models. This provides a substantive body of information on modelling this aspect. Other processes of significance identified to require consideration are anaerobic slowly biodegradable COD (SBCOD) hydrolysis to readily biodegradable COD (RBCOD), and COD loss. Both processes have significant impact on the predicted BEPR performance. Due to the uncertainties associated with the mechanisms and quantification of these two processes, it is concluded that the most extensively validated kinetic simulation model should be selected for development, and that the omissions in this model should be addressed progressively, using the relevant information drawn from the existing models, the literature and observations on ENBNRAS systems.     

Nitrous oxide generation in full-scale biological nutrient removal wastewater treatment plants

International guidance for estimating emissions of the greenhouse gas, nitrous oxide (N₂O), from biological nutrient removal (BNR) wastewater systems is presently inadequate. This study has adopted a rigorous mass balance approach to provide comprehensive N₂O emission and formation results from seven full-scale BNR wastewater treatment plants (WWTP). N₂O formation was shown to be always positive, yet highly variable across the seven plants. The calculated range of N₂O generation was 0.006-0.253 kgN₂O-N per kgN denitrified (average: 0.035 ± 0.027). This paper investigated the possible mechanisms of N₂O formation, rather than the locality of emissions. Higher N₂O generation was shown to generally correspond with higher nitrite concentrations, but with many competing and parallel nitrogen transformation reactions occurring, it was very difficult to clearly identify the predominant mechanism of N₂O production. The WWTPs designed and operated for low effluent TN (i.e. <10 mgN L⁻¹) had lower and less variable N₂O generation factors than plants that only achieved partial denitrification.     

污水除磷及回收技术

介绍了当前污水中除磷的主要方法,阐述了各种除磷方法的原理、优缺点以及常用的处理工艺,对磷回收的原理、工艺做了简单的论述,以加强对除磷技术的研究,实现磷的可持续发展。     

生物除磷机理与新工艺

综述了生物除磷的PAO和DPB原理,介绍了PASF、Dephanox和A3N-SBR三种新的脱氮除磷工艺,从而达到提高脱氮除磷效果,消除水环境污染的目的。     

废水生物脱氮新工艺研究进展

对生物脱氮新工艺进行了较全面的综述,分析了影响NO2-N积累的主要因素为游离氨、pH值、温度、溶解氧、污泥龄和有害物质,主要介绍了短程硝化反硝化、厌氧氨氧化和CANON等生物脱氮新工艺的微生物学原理,研究应用现状、发展前景以及存在的问题。     

Characteristics and fate of organic nitrogen in municipal biological nutrient removal wastewater treatment plants

The aim of this study was to investigate the occurrence and fate of colloidal and dissolved organic nitrogen (CON and DON) across biological nutrient removal (BNR) activated sludge bioreactors. Primary and secondary effluent total nitrogen (TN) measurements and component fractionation, CON and DON concentration profiles across BNR bioreactors, and laboratory batch experiments with the process mixed liquor were carried out at several full-scale BNR plants in northern Poland. The organic nitrogen (ON) components were divided into high CON, low CON, and DON based on sequential filtration through 1.2, 0.45 and 0.1 μm pore-size filters. The average influent DON_0.1μm (<0.1 μm) concentrations ranged from 1.1 g N/m³ to 3.9 g N/m³ and accounted for only 4-13% of total organic nitrogen. In the effluents, however, this contribution increased to 12-45% (the DON_0.1μm concentrations varied in a narrow range of 0.5-1.3 g N/m³). Conversions of ON inside the bioreactors were investigated in more detail in two largest plants, i.e. Gdansk (565,000 PE) and Gdynia (516,000 PE). Inside the two studied bioreactors, the largest reductions of the colloidal fraction were found to occur in the anaerobic and anoxic compartments, whereas an increase of DON_0.1μm concentrations was observed under aerobic conditions in the last compartment. Batch experiments with the process mixed liquor confirmed that DON_0.1μm was explicitly produced in the aerobic phase and significant amounts of ON were converted in the anoxic phase of the experiments.