厌氧氨氧化菌的驯化培养

厌氧氨氧化是指在厌氧条件下,厌氧氨氧化混合菌直接以NH4+为电子供体,以NO3-或NO2-为电子受体,将NH4+、NO3-或NO2-转变为N2的过程.厌氧氨氧化作为一种新型的污水处理工艺因其耗能少且不消耗碳源具有较高的理论意义和良好的应用前景.本文以活性污泥为种泥,采用SBR反应器,以NH4 Cl和NaNO2配制人工模拟废水进行厌氧氨氧化(ANAMMOX)菌的培养与驯化.在此系统中观察到了厌氧氨氧化反应,但是氨氮并没有与亚硝酸盐氮一直呈比例下降,反而有所上升,此时厌氧氨氧化菌的驯化培养仍处于初期.     

厌氧氨氧化生物脱氮研究进展

1994年,荷兰学者首先在一个反硝化流化床中发现了厌氧氨氧化（ANAMMOX）现象,后来的研究证明这是一种新型生物脱氮途径.由于ANAMMOX能同时去除氨氮和亚硝酸盐氮,且费用低,近10年来已成为生物脱氮新技术研究的热点.本文综述了ANAMMOX的反应机理,ANAMMOX菌的基本生理生化特征,国内外学者成功启动ANAMMOX反应过程的多种反应器,基于ANAMMOX原理开发的OLAND、SHARON-ANAMMOX和CANON工艺,并简要报道了作者近期以垃圾填埋场渗滤液处理的硝化活性污泥为驯化微生物,成功地在56 d里启动了ANAMMOX反应过程的结果.     

污泥厌氧消化上清液自养生物脱氮技术及应用进展

厌氧氨氧化技术与短程硝化相结合,形成的全程自养脱氮技术,与传统生物脱氮工艺相比,节省了大量碳源和曝气量,是一种可持续发展的生物脱氮技术。该工艺的核心微生物是ANAMMOX菌群,其对DO、温度、pH、FA以及FNA的浓度等环境因子敏感,进水的有机物和无机碳源等也是重要的影响因子。作为自养微生物,ANAMMOX细菌的世代时间较长,生长速率慢,很容易在水处理系统被洗脱,如何保持适合其生长的稳定环境和生物量,是厌氧氨氧化生物脱氮的关键。结合厌氧氨氧化技术的工业化应用,文章对生物短程脱氮技术未来的发展提出展望。     

部分亚硝化-厌氧氨氧化联合工艺处理含氮废水的研究

部分亚硝化-厌氧氨氧化联合工艺是一种新型的废水脱氮工艺。实验采用模拟废水,进水氨氮浓度为600 mg/L。亚硝化SBR反应器在温度为30℃、HRT为24 h、DO≈0.2 mg/L的运行条件下,将废水中的一部分氨氮氧化成亚硝氮,并使得亚硝化SBR反应器出水中NH4+-N和NO2--N比值接近1∶1.32后,再作为厌氧氨氧化SBR反应器进水;厌氧氨氧化SBR反应器在温度为37℃、HTR为24 h的运行条件下,将氨氮和亚硝氮转化为N2。实验结果表明,部分亚硝化-厌氧氨氧化联合工艺脱氮效果较好,废水中氮的去除率可达94.44%。     

新型污水脱氮工艺研究进展

阐述了污水脱氮的反应工艺,综述对比了厌氧氨氧化(ANAMMOX)工艺、短程硝化反硝化(SHARON)工艺、限氧自养硝化-厌氧反硝化(OLAND)工艺、短程硝化-厌氧氨氧化(SHARN-ANAMMOX)工艺和单相CANON(SHARON-ANAMMOX)这五种生物脱氮工艺工作原理,脱氮效果和工艺的优缺点。     

部分亚硝化-厌氧氨氧化工艺联合形式、应用及脱氮效能评析

部分亚硝化-厌氧氨氧化联合工艺与传统生物脱氮工艺相比具有一定优势,但该联合工艺是否一定优于传统生物脱氮工艺尚需论证。本文介绍了部分亚硝化-厌氧氨氧化联合工艺的组合形式、特点和处理实际废水的研究进展,从脱氮速率、能耗及碳源的角度将部分亚硝化-厌氧氨氧化联合工艺与传统生物脱氮工艺进行对比分析。指出部分亚硝化-厌氧氨氧化联合工艺具有不需要额外投加有机碳源的优点;部分亚硝化-厌氧氨氧化联合工艺虽然在曝气方面可以节省能耗,但是其中温反应需要一定的热能消耗,综合分析其处理能耗高于传统生物脱氮工艺;同时该联合工艺的整体脱氮速率与传统生物脱氮工艺相比差别不大。据此提出在选择生物脱氮工艺时需要考虑废水的碳氮比,碳氮比高时可以采用传统生物脱氮工艺,碳氮比低时可以考虑使用部分亚硝化-厌氧氨氧化联合工艺。     

厌氧氨氧化脱氮技术处理低碳高氨氮废水的影响因素探讨

传统的生物硝化-反硝化工艺已经越来越不能满足低C/N比、高氨氮废水的脱氮要求。因此,高效低耗的脱氮工艺被人们逐渐认可。近年来,厌氧氨氧化脱氮工艺具有无需外加碳源、耗氧量低、污泥产量少和运行费用省等优点,逐渐成为国内外众多学者研究的重点。探讨了该项技术处理低碳高氨氮废水的主要影响因素。     

厌氧氨氧化相关工艺处理垃圾渗滤液脱氮研究现状

垃圾渗滤液有着氨氮浓度大、碳氮比小、组成成分复杂、水质变化大、有机物质含量丰富、色度高等特点。厌氧氨氧化目前是一种新型的深度除氮技术，具有需要碳源少、氧消耗量低、污泥产量小等特点。重点介绍了几种厌氧氨氧化为基础的处理垃圾渗滤液废水的新型深度脱氮工艺，主要包括分体式短程硝化厌氧氨氧化（SHARON-ANAMMOX）工艺、一体化部分亚硝化厌氧氨氧化（CANON）工艺、一体式限氧自养硝化厌氧反硝化（OLAND）工艺。     

高氨氮制药废水短程生物脱氮

引　言短程生物脱氮的概念就是将废水中的氨氮氧化为亚硝酸盐 ,采用适当的手段阻止其进一步氧化为硝酸盐 ,然后直接进入反硝化阶段 .这样 ,将节省2 5 %因为供氧而消耗的能源 ,在反硝化过程中将节省 4 0 %的有机碳源 ,同时反应的速率大幅度提高 ,剩余污泥量大为减少[1～ 5] .实现短程硝化与反硝化的关键在于抑制硝酸菌的增长 ,从而导致亚硝酸盐在硝化过程中得到稳定的积累[6] .短程生物脱氮工艺尤其适用于低碳氮比、高氨氮、高pH值和高碱度废水的处理 ,而在处理过程中较多地采用序批式生　物反应器 (SBR) .序批式间歇活性污泥法的整个处理…     

厌氧氨氧化工艺在处理腈纶废水过程中的应用研究

厌氧序批式活性污泥法,即厌氧序批式反应器(ASBR)是一种以序批间歇运行操作为主要特征的废水厌氧生物处理工艺,依赖于形成沉降性能良好的生物体,采用单个反应器完成处理的序列操作,即进水、反应、沉降和排水。实验的设计方案是将ASBR工艺与厌氧氨氧化(ANAMMOX)技术组合应用于处理腈纶厂排放的不能够达标排放的高浓度有机废水。其中,ANAMMOX技术具有良好的有机污染物分解去除效果,氨氮(NH4+-N)的进水浓度为283.2 mg/L,经ANAMMOX技术和ASBR工艺处理后的腈纶废水出水NH4+-N浓度为20 mg/L,去除率达95%;亚硝态氮(NO2--N)的进水浓度为300 mg/L左右,经ANAMMOX技术和ASBR工艺处理后的腈纶废水出水中NO2--N未检出(NO2--N浓度为0 mg/L),去除率达100%;化学需氧量(CODcr)的进水浓度为306.3 mg/L,经ANAMMOX技术和ASBR工艺处理后的腈纶废水出水CODcr值为44 mg/L,去除率达85%。从污水处理工程应用角度看,ANAMMOX过程比传统硝化-反硝化脱氮方式具有明显优势,能够达到企业清洁生产的要求与目的。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.