组合填料厌氧/好氧生物滤池(AABF)除磷效果研究

为能提高生物滤池除磷效率,采用配对比较设计法研究了石英砂单一填料生物滤(SMAABF)和火山岩—石英砂组合填料生物滤池(CMAABF)在启动以及稳定运行过程中的处理效果。结果显示,启动过程中,CMAABF挂膜及启动时间短,对COD的去除率稳定在75%以上,但对总磷去除率不稳定。稳定运行期间,CMAABF对总磷的平均去除效率为80.21%,明显优于采用SMAABF的75.38%,t检验结果也表明,两种滤池在进水TP差异不大的条件下,出水TP存在显著差异。CMAABF对COD的去除主要发生在厌氧段火山岩层,占COD总去除效率的87.70%,对总磷的去除主要发生在好氧段火山岩层和滤池中部的石英砂层,分别占TP总去除效率的57%及30%。     

不同填料曝气生物滤池启动运行特性比较

在相同运行条件下对瓷粒和陶粒两种不同填料曝气生物滤池(BAF)启动运行进行了试验研究,对不同填料在挂膜过程中COD和NH 4-N的去除效果及出水NO-3-N和NO-2-N进行了考察,并对两种填料表面生长的生物膜进行了剥离镜检.结果表明,在常温20～25℃下两种填料所需的启动挂膜时间均有较大差异,陶粒填料所需时间为10d,而瓷粒填料则需30d.启动挂膜过程中,两个BAF对COD和NHJ-N的去除率基本相同,但所需运行时间有较大差异.陶粒填料BAF硝化效果好于瓷粒填料.镜检表明,两种填料表明生物膜中均存在着多种微生物和明显的生物相分布.     

1种聚氨酯纤维填料的水处理效果研究

采用生物滤池工艺,研究了1种聚氨酯纤维绳状编织填料的挂膜情况以及不同工况对填料处理效果的影响,并通过单因素分析研究了C/N、HRT、DO含量对污水处理效果的影响。结果表明,该填料挂膜后具有良好的脱氮效果;当COD/ρ(TN)为13.3～16.7、HRT为12～20 h、DO的质量浓度约为3 mg/L时处理效果良好,COD、TN、NH_3~-N的去除率分别达到85%、70%、70%以上。微生物镜检可知,填料表面及内部微生物丰富,这些微生物共同构成了一个复杂的生态系统,有利于COD和氮的脱除。生物滤池中有机物的降解过程无论是在好氧和厌氧阶段均符合一级反应动力学方程,且拟合相关性较好。     

适用于广州市农村生活污水处理关键技术的厌氧器研究

通过对广州市农村生活污水治理前期工程进行调研得知,前期工程厌氧器采用的都是完全挂填料与不挂填料两种工艺。选取5个监测点进行工艺的进、出水效果监测,结果显示挂填料的厌氧器水解效果要优于不挂填料厌氧器,COD、NH3-N、TN、TP经过厌氧器(挂填料)+人工湿地后处理效率高,但完全挂填料厌氧器容易堵塞。所设计的关键技术的厌氧器水解酸化效果要优于前期农村生活污水治理中所采用的厌氧器,大大提高经厌氧器后污水的可生化性,而且采用的三个结构,可以改善完全挂填料的厌氧器堵塞情况。     

MBBR不同填料挂膜启动及短程硝化特性研究

选取K2和多面空心球作为移动床生物膜反应器(MBBR)的填料,通过考察生物膜生物相、生物膜中胞外聚合物(EPS)的成分及含量、NH_4~+-N和COD去除效果等指标,对不同填料的MBBR挂膜启动特征和短程硝化动力学特性进行了研究。结果表明:K2填料生物膜较为紧实,其EPS中蛋白质和多糖含量较高;在相同运行条件下,K2填料对NH_4~+-N和COD的去除率分别可达94.46%、82.51%,高于多面空心球填料(88.24%、78.71%),且NO_2~--N积累率大于90%;采用Monod模型拟合得出动力学参数v_m=6.81 mg/(L·h)(K2填料)v_m=5.69 mg/(L·h)(多面空心球填料),这证实了K2填料利于MBBR快速挂膜启动,即能实现高效且稳定的短程硝化过程,又具有良好的底物降解能力。     

曝气生物滤池处理腈纶废水的启动性能研究

以曝气生物滤池(Biological Aerated Filter,BAF)净化腈纶废水为研究对象,研究了BAF处理腈纶废水的启动规律。试验以陶粒为滤料,在流量为25L/h,曝气量为40L/h的试验条件下,每天测试COD和氨氮的去除率变化情况。BAF对COD,氨氮有一定的去除效果。启动15d后,COD去除率达到65%;18d后,氨氮去除率达到60%以上。镜检表明,填料表面生物膜中均存在着多种微生物和明显的生物相分布。BAF挂膜过程中可以通过氨氮和COD去除率变化,来判断填料挂膜的进程和生物硝化作用进行的程度。     

气提式接触氧化法的低温实验研究

通过实验确定低温(8~15℃)条件下气提式接触氧化反应器挂膜启动期填料生物膜量SS、生物活性ρ(VSS)/ρ(SS)的具体变化过程,研究反应器在低温8~15℃条件下对生活污水的COD、NH3-N、TP处理效果,并与常温(16~28℃)条件进行对照。结果表明,在低温条件下,气提式接触氧化反应器填料挂膜成功需要18 d,COD、NH3-N、TP去除率平均达到83.1%、69.9%、20.9%;COD、TP的去除效果受温度影响最小,出水除TP外均达标。气提式接触氧化反应器是一种很好的小型低温生活污水处理装置及工艺,对低温环境适应强。     

纤维陶粒作为填料在生物滤池中的快速挂膜

以小麦秸秆和电厂粉煤灰为主要原料,辅以外加药剂(水泥、石灰、石膏、水玻璃),经混合、成球、陈化和养护工序,制得免烧秸秆-粉煤灰纤维陶粒(简称纤维陶粒),并将其作为曝气生物滤池(BAF)的载体填料进行挂膜启动。试验考察了外加药剂对纤维陶粒比表面积的影响及挂膜过程中COD、氨氮和总磷的去除情况。结果表明,外加药剂对纤维陶粒比表面积的影响主次顺序为:石灰>水玻璃>水泥>石膏;优组合为(质量分数):石灰8%,水玻璃2%,水泥3%,石膏2.5%;在优组合下制得的纤维陶粒的比表面积为7.925 m2/g;挂膜启动后,COD、氨氮和总磷的去除率呈增加趋势,10 d后趋于平稳,平均去除率分别为87.3%、74.64%和80.01%,出水水质良好。     

A／O生物膜反应器的挂膜启动

研究了A/O生物膜反应器的挂膜启动.好氧池内选用聚丙烯移动填料,缺氧池中放置半软性填料,污泥取自某市污水处理厂二沉池排出的剩余污泥,采用快速排泥法挂膜.经过40多天的培养,系统对污水的处理效果也随着生物膜的成熟逐渐提高和稳定,COD、NH3-N的去除率分别增加到73.6%和50%,表明反应器的挂膜启动过程完成.     

2套组合折流板反应器系统处理生活污水的启动运行

以厌氧污泥为种泥,采用2套填充不同填料的兼氧-厌氧组合ABR为反应器,考察了填充不同填料组合系统处理生活污水的启动运行。结果表明,当温度在25～35℃时,进水体积流量约为0.40 m3/d、HRT为24 h时,连续运行65 d后,组合单元中2种填料表面均形成一层均匀而致密的深褐色菌膜;稳定运行时,填充悬浮球型填料的组合ABR和填充组合填料的ABR对生活污水中COD的平均去除率分别为66.5%和70.1%,对SS的平均去除率分别为90.9%、92.0%,出水COD和SS含量均达到GB 18918-2002二级排放要求,且填充组合填料的系统对COD、SS、TN及TP的去除率效果均优于填充悬浮球填料的系统。     

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。