MBBR法A~2/O式工艺对污水处理厂二级出水的脱氮研究

基于污水厂二级出水中NH3-N、TN含量过高及可生化性有机碳源较低的特点,利用移动床生物膜反应器法厌氧-兼氧-好氧式(MBBR-A2/O)工艺对其进行研究。反应器采用预挂好氧膜和有机负荷递减法相结合的方式启动,通过NH3-N去除情况反应微生物的生长演化过程,并进行氮素分析。结果表明,反应器启动分为3个阶段,微生物适应阶段、微生物活性提高阶段和微生物活性稳定阶段,在低碳源的条件下,反应器经50 d挂膜启动成功,对NH3-N去除率达到85%以上;在稳定运行阶段,对NO2--N、NO3--N、TN的去除率分别为68.9%、58.1%、69.9%,说明通过A2/O反应器串联运行,系统内存在同步硝化反硝化作用,达到强化脱氮的目的。     

厌氧流化床处理红霉素废水的快速启动研究

从生物膜的形成过程,对厌氧流化床反应器的快速启动进行了深入的研究,反应器R1采用在厌氧条件下直接挂膜的方式启动;反应器R2采用先在好氧条件下生成丝状菌,然后在厌氧条件下进行挂膜.结果发现,丝状菌作为生物膜的骨架加速了生物膜的形成,缩短了反应器的启动时间,35 d就可以完成启动,而且形成的生物膜具有较好的机械性能和抗冲击负荷能力.     

厌氧生物滤池启动与挂膜实验研究

生物滤池法是一种兼有活性污泥法及生物膜法特点的新型废水处理技术.对于生物滤池挂膜启动试验中,曝气生物滤池的研究比较成熟.文章通过实验对挂膜过程中COD和氨氮值的测定,确定在厌氧条件下,生物滤池启动与挂膜成功时的实验条件.     

内循环三相厌氧生物流化床降解精对苯二甲酸废水的研究

以火山岩为载体,制作了内循环式厌氧生物流化床,通过好氧预挂膜、快速排泥、逐步提高负荷法启动,启动时间约47 d。运行稳定后,当精对苯二甲酸(PTA)废水的COD为(4 752.3±41.2)mg/L时,在水力停留时间(HRT)为(17.3±1.2)h、有机负荷(OLR)为6.5kg COD/(m3.d)条件下,COD去除率达(64.0±4.4)%,对苯二甲酸(TA)去除率达(65.1±1.3)%,生物膜量达(13.3±0.2)mgVSS/g载体。对载体进行扫描电镜分析(SEM)得知,载体内为封闭孔,厌氧生物主要生长于载体表面孔内。观测产量为Yobs0.057gVSS/g COD,载体生物基质利用速率为0.83g COD/(gVSSd)。     

复合式厌氧折流板反应器快速启动的影响因素探讨

厌氧反应器的快速启动对反应器的运行意义重大,反应器能否快速启动是评判反应器性能的重要内容。探讨了复合式厌氧折流板反应器快速启动的方法及影响因素,分析了好氧预挂膜法的优势以及接种污泥、负荷、碱度、微量元素对启动的影响,并指出了接种厌氧颗粒污泥、低有机负荷、合适的碱度是快速启动的关键要素。     

厌氧反应模型及模拟结果分析

对厌氧反应过程进行了分析,在此基础上建立了微生物生长和基质降解的数学模型,通过对单相厌氧法和二相厌氧法的模拟结果进行分析对比,发现同样的启动条件下二相法处理效率高于单相法,操作条件中的停留时间、污泥泥龄是控制厌氧状态的关键。     

厌氧复合反应器处理退浆废水的启动研究

重点研究厌氧复合反应器处理难降解退浆废水的启动,试验结果表明,在中温(35±3)℃、pH 8.0左右的情况下50 d迅速启动,COD去除率＞60%,并培养出适应水质要求的厌氧颗粒污泥;经过弹性立体(YDT)填料和组合填料的挂膜比较发现:组合填料比YDT填料挂膜快、三相分离效果好、COD去除效果高2%～8%.     

曝气生物滤池不同挂膜方法预处理微污染水源水研究

采用陶粒填料曝气生物滤池预处理微污染水源水,对接种挂膜和自然挂膜2种挂膜方式下挂膜时间、生物膜生长形态特征及对微污染有机物和氨氮的去除情况进行了试验.结果表明,接种挂膜可以加快系统启动,比自然挂膜启动时间减少1周左右,并且生物量较多;系统成功启动进入稳定运行期间,2种挂膜方式下的微生物形态和特征基本相同;系统稳定运行期间,2种挂膜方法启动系统均取得较好的微污染物去除效果,自然挂膜对COD的去除效果稍好于接种挂膜,接种挂膜对NH3-N的去除效果要好于自然挂膜.     

厌氧UASB+AF工艺处理PTA废水试验

介绍了天津石化公司利用原有接触氧化沉淀池改造为厌氧UASB+AF预处理装置,进行处理PTA废水的生产性试验。装置运行稳定可靠,成功地培养驯化了厌氧颗粒污泥,形成的污泥床颗粒化程度高。试验中采用的梅花形填料较好地克服了填料堵塞的问题,且使挂膜厚而均匀。     

微生物在变压器油中的生长研究

取土壤样通过富集、分离、纯化等方法,得到能以变压器油为唯一碳源的好氧细菌和厌氧细菌,说明自然环境中的确存在能利用变压器油为碳源生长繁殖的细菌.在不同条件下,以变压器油为唯一碳源进行好氧和厌氧培养,当体系在无游离水条件下、温度≥50℃或pH值≤5.0时,微生物均不能生长繁殖,说明在变压器油工作状态下,微生物不能在其中生长繁殖.从运行中的介损值偏高的变压器中取油样,未检测出微生物.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、不饱和聚酯树脂、环氧树脂)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.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。