化学预氧化对混凝效果的影响试验

采用静态批量试验方法,分别在水样中投加KMnO4、H2O2、ClO2和O3进行预氧化,然后再投加不同剂量的絮凝剂PAC,充分沉淀后,检测出水浊度和TOC.通过这些指标的变化来评价预氧化对混凝效果的影响.试验结果表明:浊度和TOC去除率的提高与其氧化剂的投加量有关,在最佳的氧化剂投量下,经过KMnO4或H2O2预氧化后,浊度去除率可以提高7%左右,TOC去除率提高11%以上;ClO2预氧化后浊度去除率可以提高4%左右,TOC去除率提高可以达到7%左右;O3预氧化后浊度去除率只能提高2%左右,但TOC去除率可以提高5%左右.同时还可以看出TOC的去除效果随浊度去除率的提高而增加.     

粉煤灰改性壳聚糖处理城市景观水的研究

用粉煤灰酸活化后过滤得到的滤液对壳聚糖进行改性,制备一种新型絮凝剂.用该絮凝剂对上海市和平公园、松鹤公园、鲁迅公园、彰武路某河的景观水体进行处理研究,并采用高锰酸钾预氧化,加强絮凝效果.结果表明,改性后的壳聚糖除浊、除藻效果很好,较少用量(0.6mg·L-1)可获得90%去除率.高锰酸钾预氧化强化了絮凝效果,当高锰酸钾投加量为1 mg·L-1时,改性壳聚糖的投加量大大减少(0.3 mg·L-1),藻去除率同比提高了近30%,但过高的投加量浊度去除率反而下降.     

PAC与PAC/PAM对藻类的去除效果研究

采用静态试验研究了混凝工艺对水源水中的细胞内和溶解性(细胞外)微囊藻毒素的去除效果,并初步探讨了其去除机理。试验结果表明,当将原水的pH值调节到5.5~6.0混凝剂投加量定为30 mg/L时,对去除水中的细胞内微囊藻毒素效果明显,此方法的去除率可以达95.3%。PAC/PAM工艺对藻浓度、浊度的去除率都要高于PAC工艺,但对藻毒素的去除效果二者都不显著。但在混凝前投加活性炭,对源水进行预氧化处理,实验结果表明,PAC/PAM+C工艺可以显著地提高对溶解性微囊藻毒素的去除效果,去除率达到50%到60%,主要是因为混凝工艺的强化作用与活性炭结合能够明显地去除弱疏水性有机物。     

溶藻菌及PAC絮凝技术联合除藻研究

以富营养湖泊底泥作为菌种来源,从中分离纯化出溶藻菌,并将溶藻菌和铜绿微囊藻藻液混合培养,考察其抑藻效果,结果表明,抑藻率最高可达46.7%。让所得菌株以聚合氯化铝(PAC)为载体制备溶藻菌菌剂,研究菌剂投加量、pH值对藻去除率的影响,结果表明,当菌剂投加量为10 mg/L时,叶绿素a去除率达到83.4%,pH在7~8范围内的时候除藻降浊效果最好,去除率达到90%以上。     

二氧化氯杀灭水中铜绿微囊藻的影响因素

试验研究了二氧化氯与铜绿微囊藻的接触时间、二氧化氯投加量、藻初始浓度、pH值、有机物和氨氮含量对二氧化氯杀灭铜绿微囊藻效果的影响,考察了二氧化氯与混凝工艺的协同除藻效果。结果表明,二氧化氯与铜绿微囊藻最佳接触时间为10min。铜绿微囊藻杀灭率随二氧化氯投加量增大而提高,随pH值升高及有机物含量的增大而下降。由氯化铵形成的氨氮的存在对溶液的pH值有影响而使铜绿微囊藻杀灭率稍有提高。当叶绿素d初始浓度低于27．12μg／L时,二氧化氯杀藻率随藻初始浓度的升高而提高,但当叶绿素a初始浓度高于27．12μg/L时,杀藻率随藻初始浓度的升高而逐渐下降。二氧化氯与混凝具有协同除藻作用,当二氧化氯的投加量为0．5mg／L,聚合氯化铝10mg／L时,铜绿微囊藻杀灭率达到96．17％。     

聚二甲基二烯丙基氯化铵对铜绿微囊藻的去除效果研究

研究了聚二甲基二烯丙基氯化铵(PDMDAAC)对实验室培养的铜绿微囊藻和藻液中的胞外分泌物及天然有机物的去除效果,以及藻浓度、pH等因素对除藻效果的影响.结果表明,PDMDAAC具有良好的除藻能力,在投加量为2.8 mg.L-1时即可达到98%的藻去除率,并可去除80.7%的溶液中TOC.PDMDAAC还具有有效的抑制藻类生长的能力.     

化学预处理对用高岭土助凝去除铜绿微囊藻的影响的研究

用高锰酸钾和硫酸铜分别对铜绿微囊藻进行化学预处理,再通过烧杯搅拌试验研究以高岭土为助凝剂,用PAC絮凝去除经过了化学预处理后的铜绿微囊藻的效果。结果表明,高锰酸钾或硫酸铜预处理以不同方式影响叶绿素a（Chla）和浊度的去除。Chla的去除率随高锰酸钾投加量的增加而增加,且在1.0 mg/L投加量时达到92.6%。而硫酸铜预处理时Chla的去除率在其投加量为0.2 mg/L时最高,但在1.0 mg/L时减少到72.8%。高锰酸钾或硫酸铜化学预处理的除藻效果一般不如用高岭土助凝。甚至经高锰酸钾或硫酸铜预处理后,再用高岭土助凝除藻的效果也有所下降。就处理效率和饮用水安全而言,用高岭土助凝是优于用高锰酸钾或硫酸铜进行除藻预处理的技术。     

高锰酸钾预氧化与聚合氯化铝絮凝对藻类去除能力研究

采用高锰酸钾预氧化与聚合氯化铝(PAC)混凝,对去除水中的微囊藻进行了研究。通过正交试验得出了在试验水质条件下,PAC对叶绿素a的最大去除率为72%,高锰酸钾投加量为0.5 mg/L,预氧化时间为5 min时,叶绿素a的去除率可达93.1%。预氧化产生的水合二氧化锰作为凝结核促进了絮体的形成,并使之更加密实、易沉降。     

过氧化氢预氧化去除受污染地下水中铁、锰的试验研究

通过单因素试验考察了过氧化氢投量、进水pH、预氧化时间及原水本底成分对过氧化氢预氧化去除长沙市近郊某镇受污染地下水中铁、锰效果的影响。试验结果表明,当过氧化氢投加量为0.13 mg·L-1时,铁、锰的去除率分别达到92.8%和25.6%;酸性环境有利于铁、锰的去除,当pH=5.01时,铁、锰的去除率达到最大的94.6%和48.0%;预氧化60 min,锰的去除率达到最大的56.2%,而铁的去除率随预氧化时间的增长无明显变化,保持在90%左右;原水本底成分对过氧化氢预氧化除锰的效果影响不明显。     

臭氧+混凝沉淀处理微污染水试验研究

研究臭氧 混凝沉淀处理低温微污染水的净水效果.采用静态试验,改变臭氧投加量,接触氧化时间等参数,分别对比了CODMn、浊度和色度的去除效果.臭氧投加量为3 mg·L-1接触氧化时间为15 min时,沉淀后出水的高锰酸盐指数、浊度、色度比直接采用聚合氯化铝混凝的去除率分别提高了5.4%、20.3%和20.1%.对于低温微污染水源水,臭氧 混凝沉淀工艺能有效地去除有机物、浊度、色度,使处理后水质达到饮用水水质标准.     

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。