强化反应器中厌氧颗粒污泥的形成过程

ASBR反应器是在水污染防治领域近年来出现的一项新技术。在工业废水处理过程中，反应器能培养出具有优良性状的厌氧颗粒污泥。本研究是将分离、筛选并经优化组合的优势菌群与厌氧污泥—同加入ASBR反应器中，对啤酒废水进行处理。本文就啤酒废水处理过程中厌氧颗粒驯化过程及微生物群落等进行光学显微镜和扫描电镜跟踪观察和研究。     

厌氧氨氧化颗粒污泥的快速形成

以好氧硝化颗粒污泥与厌氧氨氧化生物膜作为接种污泥,在缺氧条件下利用EGSB反应器培养厌氧氨氧化颗粒污泥。根据反应器内污泥性状以及运行效果,随时调整反应器的进水基质浓度以及上升流速等关键控制因素,加快厌氧氨氧化颗粒污泥的快速形成。同时考察系统的脱氮效能、粒径分布、厌氧氨氧化颗粒污泥表面形态以及内部结构与微生物分布情况。反应器运行80 d后,培养出成熟的厌氧氨氧化颗粒污泥,平均粒径为0.556 mm;89 d时,总氮去除负荷达4.758 kg N·m-3·d-1。FISH表明颗粒污泥中厌氧氨氧化菌为优势菌种,同时SEM与TEM观察表明颗粒污泥是由多个小颗粒聚集形成,而且形状不规则,内部结构排列紧密。     

厌氧颗粒污泥研究进展

厌氧污水处理工艺已经成功地应用到很多领域,目前大多数高效厌氧反应器的良好处理效果取决于高活性厌氧颗粒污泥.而颗粒污泥的性质、结构以及形成机理也成为国内外学者研究的热点.简述了厌氧颗粒污泥的基本特征以及形成机理.综述了近年来国内外学者对颗粒污泥的研究成果,包括影响厌氧颗粒污泥形成因素以及厌氧颗粒污泥的应用,指出了厌氧颗粒...     

厌氧颗粒污泥的形成及其应用的研究进展

厌氧颗粒污泥在上流式厌氧反应器内发挥着重要的作用,在工业生产中厌氧颗粒污泥也得到了广泛的应用。关于颗粒污泥形成的影响因素,研究者探究了惰性物质、金属离子和菌类的添加对颗粒污泥形成的影响。但就其形成原因至今尚未有一个较为全面的理论。文章针对颗粒污泥的形成和应用,综述近年的研究进展。     

含铁矿物质粉末促进厌氧氨氧化颗粒污泥形成及颗粒特征分析

为了促进厌氧氨氧化颗粒污泥的形成，提高污泥沉降性能，向启动初期的UASB厌氧氨氧化反应器中投加粉末状天然含铁矿物，从反应器性能、污泥变化情况和颗粒污泥特征等方面研究分析了该条件下厌氧氨氧化污泥的颗粒化过程。在投加含铁矿物质粉末后，颗粒污泥占比从反应器体积的0.9%提高到了15%，颗粒污泥平均密度从1.027 g/cm³增加到了1.080 g/cm³，污泥SVI从98.65 mL/g[VSS]降至33.51 mL/g[VSS]，反应器中颗粒污泥的形成速率明显提高，颗粒污泥比重增加，污泥沉降性能显著提升。含铁矿物质粉末的投加有效地促进了厌氧氨氧化污泥的颗粒化过程，提高了颗粒污泥的沉降性能。     

厌氧氨氧化颗粒污泥的快速形成

以好氧硝化颗粒污泥与厌氧氨氧化生物膜作为接种污泥,在缺氧条件下利用EGSB反应器培养厌氧氨氧化颗粒污泥。根据反应器内污泥性状以及运行效果,随时调整反应器的进水基质浓度以及上升流速等关键控制因素,加快厌氧氨氧化颗粒污泥的快速形成。同时考察系统的脱氮效能、粒径分布、厌氧氨氧化颗粒污泥表面形态以及内部结构与微生物分布情况。反应器运行80 d后,培养出成熟的厌氧氨氧化颗粒污泥,平均粒径为0.556 mm;89 d时,总氮去除负荷达4.758 kg N·m^-3·d^-1。FISH表明颗粒污泥中厌氧氨氧化菌为优势菌种,同时SEM与TEM观察表明颗粒污泥是由多个小颗粒聚集形成,而且形状不规则,内部结构排列紧密。     

浸没式双轴旋转厌氧膜生物反应器的污泥特性研究

研究了新型浸没式双轴旋转厌氧膜生物反应器(SDRAnMBR)处理模拟啤酒废水的污泥特性.结果表明,SDRAnMBR的污泥活性高,旋转剪切力没有对厌氧颗粒污泥的性质造成破坏并具有性能良好的絮体;而且能有效减轻污泥浓度、EPS、污泥粘度,污泥颗粒粒径的变化对膜污染的影响,使之能在较高的MLSS(18～19.5 g·L-1),较高的EPS浓度(50.9～63.9 mg·gMLSS-1)、较小的污泥颗粒粒径(4.00～36.54μm)和较大的污泥粘度(6.6～7.5mPa·s-1)时稳定运行.SDRAnMBR中由膜旋转形成的三相旋转流和厌氧颗粒污泥的协同作用,使SDRAnMBR具有性能良好的活性污泥,同时强化了膜组件的抗污染性能.     

厌氧颗粒污泥研究进展

探究厌氧颗粒污泥形成的机理,总结介绍国内外厌氧颗粒污泥形成模型,并对厌氧颗粒污泥的培养条件、影响因素以及对培养好的颗粒污泥如何保存进行了分析总结.在此基础上提出展望.     

长链脂肪酸对厌氧颗粒污泥产甲烷毒性研究

在间歇培养中研究了不同长链脂肪酸（LCFA）对UASB和EGSB两种反应器厌氧颗粒污泥的产甲烷毒性。结果表明，庚酸，癸酸和油酸对厌氧颗粒污泥产甲烷活性有较强的抑制，EGSB反应器厌氧颗粒污泥对LCFA的抑制表现出比UASB反应器厌氧颗粒污泥更大的耐受能力，LCFA主要通过在颗粒污泥厌氧微生物的吸附而破坏菌体细胞膜的结构。直接杀死厌氧微生物，厌氧颗粒污泥中，利用乙酸的甲烷菌和产氢产乙酸菌受到LCFA的抑制较严重。利用甲酸和利用氢气的甲烷菌受到的抑制程度较小。     

厌氧生物处理反应器概述

概述了厌氧消化阶段理论与厌氧消化的主要影响因素;介绍了厌氧生物反应器的发展历史;并对几种典型的高效厌氧生物反应器（上流式厌氧污泥床,厌氧折板反应器,厌氧膨胀颗粒污泥床和内循环式反应器）的工作原理、构造、技术特点、运行机制及其应用情况等做了详尽的阐述;最后,对厌氧反应器今后的研究方向给予了展望。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

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.     

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.     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.