甘油碳源对市政污水强化生物除磷的影响及机理

针对生物除磷效率常因市政污水进水碳源不足而低下的问题,研究建立了厌氧/好氧活性污泥反应器并评估了甘油与市政污水进水挥发性脂肪酸(VFA)比例对生物除磷的影响。结果表明,甘油可作为补充碳源用于强化生物除磷,并且甘油与VFA的优化质量比为1/1。甘油与VFA质量比为1/1有助于厌氧释磷和好氧吸磷,并且聚羟基脂肪酸酯(PHA)的合成量最大,糖原质的降解量最大。甘油厌氧降解产生乙酸和丙酸小分子有机酸是强化生物除磷的关键原因。此外,甘油与VFA比例也影响生物除磷关键酶PPX和PPK的活性,当甘油与VFA质量比为1/1时,外切聚磷酸酶和聚磷酸激酶的相对活性最高。     

十二烷基二甲基苄基氯化铵对生物除磷的影响研究

利用静态研究了十二烷基二甲基苄基氯化铵(DDBAC)对生物除磷的影响,通过设置不同DDBAC含量及空白对照对好氧吸磷和厌氧释磷进行了分析.结果表明,厌氧初始COD在400mg·L-1左右时,随着DDBAC负荷的增加,系统释磷能力增强;随着DDBAC含量的增加,吸磷速率降低直至丧失了吸磷特性;DDBAC的存在对生物除磷系...     

亚硝氮为电子受体缺氧吸磷的试验研究

为进一步了解反硝化除磷菌,以SBR反应器在厌氧/好氧条件下培养的聚磷菌为对象,进行批次试验,研究了不同浓度NO_(2-)~--N对缺氧吸磷过程的影响。结果证实:NO_(2-)~--N可以作为缺氧吸磷的电子受体,但吸磷速率比好氧吸磷低,吸磷量比好氧吸磷少。反应开始时的NO_(2-)~--N/P对反应过程影响很大,该试验中NO_(2-)~--N/P为0.60时缺氧吸磷量和吸磷速率均达到最高。低于该值时,吸磷量和吸磷速率随着氮磷比的提高而增加,NO_(2-)~--N消耗完时,体系出现"二次释磷"现象;高于该值时,吸磷量和吸磷速率随着氮磷比的提高而减少。NO_(2-)~--N浓度达到80mg/L时,没有发现对反应的抑制作用。     

m(C)/m(P)对污泥絮体中磷形态与分布及除磷能力的影响

采用连续流强化生物除磷系统(EBPR),研究进水m(C)/m(P)对聚磷菌(PAOs)的除磷能力和污泥絮体中磷的形态与分布的影响。结果表明,在进水m(C)/m(P)分别为100、65、45条件下,系统有稳定高效的除磷效果,磷的去除率维持在88%以上。将进水m(C)/m(P)由100降低至45,PAOs可以合成和消耗更多量的单位污泥胞内聚合物,污泥好氧消耗单位PHA的吸磷量由0.52 mg/(mg·L)提高至0.64 mg/(mg·L);低m(C)/m(P)的污泥表现出更高的TP和各形态磷含量,且在厌氧、好氧过程中,污泥中TP和无机磷有更大的增加量,对应着更显著的生物除磷过程,对应着低m(C)/m(P)的污泥絮体有更强的好氧吸磷能力。     

强化生物除磷系统除磷性能分析

采用厌氧/好氧和厌氧/缺氧两阶段方法培养反硝化聚磷菌,研究了第一阶段系统的除磷性能。结果表明,稳定运行的强化生物除磷系统,具有良好的除磷性能,出水磷的质量浓度小于0.5 mg/L,除磷率大于93%。通过厌氧/好氧交替方式运行,反硝化聚磷菌占聚磷菌的比例约为21.2%。缺氧段硝酸盐的消耗量与磷的摄取量成线性关系,缺氧吸磷速率约为好氧吸磷速率的49.3%。     

生物除磷的电场强化作用研究及动力学初探

本课题通过对比试验对生物除磷的电场强化作用及其动力学进行了初步研究,结果表明,在试验条件下(电流密度:i=0．04～0．08mA／cm2),无论哪个反应时段(厌氧段、好氧段)施加电场,对提高、稳定生物除磷效率都有积极的作用;且厌氧放磷反应及好氧吸磷反应都近似地符合一级动力学规律,电场可增大厌氧放磷及好氧吸磷速率常数,从而提高、稳定生物除磷效率。     

SBR污水处理工艺中磷的转化及去除机理研究

采用厌氧-好氧SBR反应器(A/OSBR)处理含磷废水,研究不同温度条件下磷的转化过程及去除机理。结果表明,温度对总磷(TP)和总有机碳(TOC)的去除影响并不明显。TP的去除率均达到95%以上。这主要是由于反硝化除磷过程的发生。反应器中污泥胞内聚合物主要以PHB的形式存在,PHV和PH2MV含量相对较低。而温度对PHB在好氧阶段的消耗的影响并不明显。     

人工配水和实际污水(AO)2SBR同步脱氮除磷比较研究

在污泥停留时间为15d、HRT为1.5h和DO的质量浓度约为2.5 mg·L-1条件下,分别对人工配水和实际生活污水进行了(AO)2SBR法同步脱氮除磷试验,并对处理效果进行了对比.结果表明,人工配水和实际污水的(AO)2SBR工艺好氧和缺氧脱氮除磷过程几乎全部以厌氧阶段合成的胞内聚羟基烷酸为碳源,说明反硝化脱氮除磷确实可实现“一碳两用”;人工配水和实际污水的好氧吸磷率分别为67.49％和93.42％、缺氧除氮率分别为58.22％和77.98％,实际污水驯化得到的反硝化聚磷菌和聚磷菌具有更强的反硝化能力和好氧吸磷能力.     

同步去除并富集磷酸盐生物膜的驯化研究

为获得高浓度富磷溶液,开展了以高磷溶液(15 mg/L)驯化培养挂式尼龙生物膜的人工配水实验,考察了溶解氧、好氧段有机物对反应器除磷效能的影响。通过扫描电镜(SEM)和能谱仪(EDS)探究反应器运行过程中微生物形态演变和污泥中的磷的质量分数。同时对好氧段存在有机物和不存在有机物时的除磷效能进行了研究。结果表明,当好氧段存在有机物时,好氧段不加有机物时微生物吸磷能力和释磷能力更强,降低了工艺运行成本。SEM-EDS表征结果表明,随着反应器的运行,细菌形态从以球菌为主演变为以短杆菌为主,污泥中P的质量分数由1.2%增长至4.4%,成功实现了聚磷菌的富集。     

生物除磷的研究进展

强化生物除磷工艺(厌氧/好氧工艺)已经在世界各地广泛应用,然而,在各地不同条件的运行过程中,成功和失败的记录均有大量报道。为解决此工艺的不稳定因素,近年来研究者对此工艺的机理作了大量的研究,包括主导微生物的鉴定,生化代谢途径的探讨以及数学模型的建立等。同时,有研究者发现,生物除磷可以在单级好氧工艺中实现,此发现可能开发出一种经济、简单的生物除磷工艺,即通过"一步氧化法"实现有机物与磷的同步去除,具有重要的意义。本文系统的总结了传统厌氧/好氧生物除磷工艺和单级好氧生物除磷工艺的最新研究进展,以期为工程技术人员提供参考。     

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.     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

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.