新型生物脱氮工艺--OLAND工艺

OLAND工艺是基于亚硝酸型硝化-厌氧氨氧化脱氮技术而开发的生物脱氮新工艺.该工艺首先采用限制溶解氧浓度实现氨氮的部分亚硝化并实现亚硝酸盐氮的浓度积累,接着进行厌氧氨氧化反应,从而达到去除含氮污染物的目的.与传统生物脱氮工艺相比,该工艺具有耗氧量少、污泥产量少、不需外加碳源等优点.     

不同生物脱氮路径下氧气、碳源等需求理论分析

生物脱氮是一种节约资源能源、环保安全的脱氮途径,但其反应复杂、路径众多,在不同的条件下找到合适的途径进行高效生物脱氮就成了必须要解决的问题。借助生物脱氮方程式进行理论分析,全面介绍了全程硝化+全程反硝化、短程硝化+短程反硝化、短程硝化+厌氧氨氧化和全程硝化+部分反硝化+厌氧氨氧化等四种常用的生物脱氮路径的特点,并计算了不同脱氮路径中理论的氧气、碳源、碱度的消耗量和活性污泥的产生量。研究分析发现,以CANON工艺为代表的短程硝化+厌氧氨氧化路径相比全程硝化+全程反硝化路径,可节约56%的氧气、100%的BOD_5、44%的碱度,少产生81%的污泥;全程硝化+部分反硝化+厌氧氨氧化路径相比全程硝化+全程反硝化路径,可节约42%的氧气、77%的BOD_5,少产生63%的污泥。     

高浓度氨氮废水的高效生物脱氮途径

回顾了传统生物脱氮的一般原理,介绍了亚硝酸盐硝化／反硝化、同时硝化／反硝化、好氧反硝化和厌氧氨氧化等提高生物脱氮效率的可能途径,并分析了他们各自的原理、实现条件和应用前景。     

ANAMMOX与反硝化耦合脱氮反应研究进展

厌氧氨氧化具有无需添加碳源无需曝气等低运行费用优点,是最简捷、经济的生物脱氮途径。研究表明,反应器中可能同时存在厌氧氨氧化与反硝化两种主要脱氮过程。本文主要对ANAMMOX与反硝化耦合脱氮反应的理论研究进行了阐述,并指出了今后研究建议。     

生物脱氮新技术

结合生物脱氮机理,介绍了同步硝化反硝化、短程硝化反硝化及厌氧氨氧化等新的生物脱氮技术的机理、影响因素、代表工艺及其技术特点,指出这些技术都具有经济、高效、低耗的优势,符合可持续发展要求,应在此基础上进一步开发适合中国国情的生物脱氮工艺。     

谈废水生物脱氮过程中的几个问题

讨论了在传统生物硝化反硝化脱氮过程中亚硝酸盐、氨和无机碳对脱氮过程的影响，分析了各自的抑制浓度和条件，提出了对这些抑制问题的解决方法。     

铁氨氧化污水生物脱氮技术的研究进展

近年来新发现的铁氨氧化过程(Feammox)能够在厌氧条件下以三价铁离子[Fe(Ⅲ)]为电子受体将铵根离子(NH4+)直接氧化为氮气(N2)、硝酸根(NO3-)或亚硝酸根(NO2-),能够耦合厌氧氨氧化过程、反硝化过程或铁盐反硝化(NDFO)过程完成污水生物脱氮。铁氨氧化相比传统硝化反硝化过程具有诸多优点,如不需要有机碳源、无需曝气、对重金属有更高的耐受力等。对铁氨氧化的发现过程、反应机制、菌种分布及其在污水生物脱氮领域的应用进行了综述,并在对铁氨氧化脱氮研究现状进行深入分析的基础上,指出了铁氨氧化工艺面临的挑战和可能的研究方向。     

BIOFOR生物滤池的反硝化/厌氧氨氧化协同脱氮研究

结合大连马栏河污水处理厂二期工程,介绍了水解酸化/前置反硝化BIOFOR生物滤池组合新工艺,重点研究了反硝化生物滤池对氮的去除效果.研究发现:在反硝化生物滤池中,除了反硝化反应外,还发生了厌氧氨氧化反应,其对氨氮和硝态氮的去除量分别为2.78、1.93 mg/L.     

高氨氮废水的前置厌氧氨氧化脱氮研究

采用前置厌氧氨氧化生物滤池+亚硝化生物滤池的组合工艺,对高氨氮焦化废水进行脱氮研究,利用亚硝化生物滤池回流液中的亚硝酸盐氮与废水中的氨氮进行反应,以达到脱氮的目的,同时考察了HRT、回流比、DO浓度、p H值等参数对脱氮效果的影响。结果表明:当废水中的氨氮和COD浓度分别为(100~120)、(60~80)mg/L时,控制厌氧氨氧化段混合进水的p H值为8.0、HRT为30 h,亚硝化段出口DO浓度为0.6~1.0 mg/L,回流比为300%,对废水的脱氮率可稳定在80%左右。     

生物脱氮工艺处理含盐废水研究进展

本文主要论述了生物脱氮工艺处理盐废水主要策略、微生物机体调节渗透压机制、以及相容性溶质的作用机理。其中相容性溶质策略在目前来看最为经济有效。研究厌氧氨氧化耦合反硝化工艺运用相容性溶质处理含盐有机废水对于拓展生物脱氮工艺的实际应用领域具有的重要的理论指导意义。     

氯胺消毒给水管网中的硝化作用及其控制

介绍了氯胺消毒管网中的硝化作用及其控制方法。研究表明,在采用氯胺消毒的给水管网中,存在着硝化反应发生的可能性。硝化作用会造成出水亚硝酸盐含量升高、消毒剂含量降低、异养菌繁殖等危害,水中的氨氮是引起该问题的主要原因。国外对氯胺消毒管网中硝化作用的研究主要集中在硝化作用与水质的相互影响方面,但对硝化作用成因的研究还不系统,部分研究的结论还属于推断性结论。目前我国部分城市给水管网中已经出现硝化现象,但还没有对氯胺消毒产生的硝化作用进行系统研究,指出在我国开展给水管网中硝化作用的研究是非常必要的。     

短程硝化反硝化工艺简析

指出短程硝化反硝化工艺是目前国内外生物脱氮技术研究应用的热点,通过介绍短程硝化反硝化工艺原理,分析了不同工艺稳定亚硝态氮积累实现短程硝化的工艺控制措施,对短程硝化反硝化工艺今后的研究和应用进行了展望。     

Nitrification and denitrification in water and soil environments

An overview of nitrification and denitrification in the natural environment is presented and the basic mechanisms of nitrification and denitrification in water/soil environments are described in this paper. Nitrification/denitrification is one of the most important techniques for removing inorganic nitrogenous compounds in water and soil environments. Nitrification and denitrification in aquatic and soil environments can be described by using First‐order kinetic and the methods for parameter estimation are discussed. The study indicated that nitrification and denitrification could take place simultaneously in aerobic and anaerobic zones in soil and water environment. The factors effecting nitrification and denitrification are discussed in this study. External carbon sources are the most important factors for completing denitrification and dissolved oxygen (DO) is very significant for nitrification.     

The effect of dissolved oxygen concentration on nitrification

The effect of dissolved oxygen concentration on the rate of nitrification has been investigated by a number of researchers using both pure and mixed cultures, and cultures found in wastewater treatment systems. The maximum growth rate of both nitrification reactions are reported to be affected by dissolved oxygen concentration over the range of 0.3 mg l⁻¹ to as much as 4.0 mg l⁻¹. In some instances, it has been reported that a dissolved oxygen concentration in excess of 4.0 mg l⁻¹ is required to achieve maximum nitrification rates, while other investigators have found that only 0.5 to 1.0 mg l⁻¹ is required.It has been proposed that several factors are responsible for the wide range of reported nitrification rates with varying dissolved oxygen concentrations. Among these factors are the effects of oxygen diffusion in flocs, variation between measured results due to steady-state and dynamic measuring techniques, and double-substrate limited kinetics. This paper reviews the nitrification literature with respect to the effects of dissolved oxygen concentration, and shows that double-substrate limiting kinetics could account for the variation in the reported results.     

城市污水短程硝化的实现途径

探讨了影响废水中亚硝酸盐积累的三大主要因素：溶解氧、温度和pH。针对常温低氨氮城市污水,从理论上分析了以活性污泥法和生物膜法的形式进行亚硝化的启动方法和运行策略,为短程硝化／厌氧氨氧化工艺在城市污水处理中的应用提供了可借鉴的研究基础。     

短程硝化-反硝化生物脱氮技术研究

对传统生物脱氮工艺原理和短程硝化—反硝化工艺原理进行了比较 ,分析了短程硝化 -反硝化技术的实用价值 ,提出了实现短程反硝化的控制条件。     

Nitrifying and heterotrophic population dynamics in biofilm reactors: effects of hydraulic retention time and the presence of organic carbon

Two biofilm reactors operated with hydraulic retention times of 0.8 and 5.0 h were used to study the links between population dynamics and reactor operation performance during a shift in process operation from pure nitrification to combined nitrification and organic carbon removal. The ammonium and the organic carbon loads were identical for both reactors. The composition and dynamics of the microbial consortia were quantified by fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes combined with confocal laser scanning microscopy, and digital image analysis. In contrast to past research, after addition of acetate as organic carbon nitrification performance decreased more drastically in the reactor with longer hydraulic retention time. FISH analysis showed that this effect was caused by the unexpected formation of a heterotrophic microorganism layer on top of the nitrifying biofilm that limited nitrifiers oxygen supply. Our results demonstrate that extension of the hydraulic retention time might be insufficient to improve combined nitrification and organic carbon removal in biofilm reactors.     

Bioaugmentation for nitrification at cold temperatures

Bioaugmentation of nitrifying bacteria for short solids retention time (short-SRT) nitrification is an attractive alternative for wastewater treatment plants in cold climates or for those in the process of upgrading to include nitrification. One possible source of ammonia for the production of nitrifying bacteria is the liquor generated during the dewatering of anaerobically digested sludges. The objectives of this study was to determine the impact of sudden decrease in temperature on nitrification rates and to determine if nitrification could be accomplished in sequencing batch reactors (SBRs) at 10 degrees C by seeding nitrifying bacteria acclimated to 20 degrees C. In this research, biomass produced during warm nitrification of dewatering liquor was seeded into cold SBRs at various hydraulic retention times from 43.3 to 96 h. The average decreases in nitrification rates were 58%, 71% and 82% for biomass cooled to 10 degrees C when the biomass was acclimated to 20 degrees C, 25 degrees C and 30 degrees C, respectively. The seeded SRTs of the cold SBRs were raised above the minimum solids retention time (SRT(min)) required for nitrification. Full ammonia nitrogen removal was achieved in cold SBRs that were operated at an apparent SRT less than SRT(min).     

生物脱氮反应器同步硝化反硝化研究

以生活污水为处理对象,对一体式悬浮载体膨胀床(ISCEB)生物脱氮反应器同步硝化反硝化现象进行了研究,并研究了DO、C/N比及进水有机负荷等因素对同步硝化反硝化的影响。     

氯胺消毒的配水系统中硝化作用的研究进展

对氯胺消毒的配水系统中的硝化现象及其危害,以及近年来国内外有关硝化作用的影响因素和检测方法等方面的研究进展进行了综述.探讨了分子生物学分析技术在对硝化细菌进行结构分析和定量评估中的应用,以及在硝化细菌培养过程中尚待解决的问题.