陶瓷膜处理地表水的工艺

采用混凝沉降与陶瓷膜超滤的组合工艺处理地表水,考察操作模式、膜孔径、膜构型以及膜通量等对膜过滤性能的影响。结果表明:在恒压操作下,终端过滤的操作压差应小于0.075 MPa,对于孔径大于50 nm的陶瓷膜而言,膜通量随孔径变化不大;错流过滤的膜通量随孔径增大而增大;错流过滤的渗透通量是终端过滤的1.5～2.2倍。恒通量操作下,蜂窝陶瓷膜过滤性能优于19通道陶瓷膜,并在恒通量150 L/(m2.h)下稳定运行。混凝沉降-陶瓷膜组合工艺对浊度的去除率大于99%,对吸收254 nm波长紫外线有机物(UV254)的去除率大于47.7%,产品水的部分指标优于GB 5749—2006中的指标。     

往复旋转管式陶瓷膜超滤脱脂奶水溶液的研究

往复旋转管式陶瓷膜过滤系统通过膜组件往复旋转在膜表面反复产生高剪切率,达到减缓膜污染的效果。在相同操作条件下,与单向旋转过滤和死端过滤相比较,往复旋转过滤具有更好的减缓膜污染的作用。本实验利用往复旋转膜过滤装置超滤脱脂奶水溶液,考察了各种参数对该膜系统过滤特性的影响。实验结果表明,料液浓度增大,膜通量减小;过高的操作压差将会抑制膜通量增加;旋转速度增大,膜表面剪切强化作用增强,膜通量相应增大;膜稳态通量随往复旋转周期增大呈现先增大后减小的趋势。当料液速度达到膜组件转速时,瞬时反方向旋转膜组件,膜表面产生最大的剪切率,膜稳态通量也达到最大值。能耗分析表明,往复旋转过滤较单向旋转过滤单位通量能耗低。     

二氧化钛动态膜在油水乳化液分离中的应用研究

以多孔管式炭膜为载体制备二氧化钛动态膜并开展动态膜分离油水乳化液的研究,考察了载体孔径对动态膜的截留率和稳定渗透通量的影响。实验结果表明,动态膜处理油水乳化液的截留率在98%以上,渗透液浓度低于8.3mg·L-1,达到国家环保排放要求;稳定渗透通量随载体孔径的增大先减小后增大。在实验基础上,提出了动态膜稳定渗透通量衰减率(FDR)的概念,并将FDR的变化趋势与动态膜类型进行关联研究。分析发现,FDR随载体孔径的增大先增大后减小,动态膜由完全堵塞过滤型过渡为中间堵塞过滤型;用中间堵塞过滤型动态膜过滤油水乳化液时,随着载体孔径的增大,渗透通量衰减变缓。     

膜振动过滤通量的实验研究

针对膜过滤过程中,因污染造成膜渗透通量下降等问题,提出了全新的将膜过滤与机械振动结合的膜振动过滤方式;用粘土悬浮液做正交实验,对比了在相同操作条件下,膜振动过滤及无振动膜过滤的膜过滤通量随时间的变化情况,表明膜振动过滤通量比无振动膜过滤通量大,并验证膜振动过滤方式的可行性;通过对影响因素的分析明确了振动频率适中、振动振幅较大时,膜过滤通量越大的原因。     

钛金属膜过滤油田污水的污染阻力研究

以阻力系列模型为基础,考察了钛金属膜过滤油田污水时膜结构和操作条件等因素对污染阻力的影响。结果表明:滤饼层阻力是主要阻力,膜孔堵塞阻力为第二关键阻力。膜孔径增大,滤饼层阻力降低,膜孔堵塞阻力增加,且二者均随压力增加而增大;随着膜面流速的增加,滤饼层阻力降低,膜孔堵塞阻力增大;在过滤操作的前15～20min,污染阻力增长迅速。实验所得结论将为确定最佳工艺条件和膜清洗方法提供可参考的依据。     

探究滤膜的振动过滤方法

借鉴大量国内外关于膜过滤分离先进技术研究成果并结合膜过滤生产实际,发现随过滤时间增加,膜污染加重导致过滤通量减小的问题。为此提出了一种新型的将膜过滤与机械振动相结合的膜振动过滤分离方式,即膜振动过滤,使之达到在保证膜过滤通量的基础上,又能有效防止膜阻塞的目的。从理论上分析证明膜振动过滤可行性,并应用自行设计、制造的具有控制振动振幅和频率的膜振动过滤装置进行过滤实验。通过实验测定膜过滤通量随过滤时间变化情况和过滤液体的透光值,证明了在合理操作条件下膜振动过滤的有效性和可行性。     

陶瓷膜分离钛硅分子筛的实验与模型计算

在面向过程的陶瓷膜材料设计理论模型的基础上,以TS-1钛硅分子筛悬浮液固液分离为应用体系,计算了陶瓷膜分离过程的操作条件与渗透性能的关系,与实验结果有良好的一致性.计算表明,对于平均粒径为290 nm的钛硅分子筛体系,陶瓷膜存在最优孔径区间(200~300 nm),使膜保持高渗透通量.孔径小于200 nm时膜通量随孔径增大而增大,孔径大于300 nm时膜通量随孔径增大而减小;采用孔径为200 nm的陶瓷膜过滤钛硅分子筛,渗透通量随时间的变化关系与模型预测结果一致,稳定通量达到800 L/(m2.h).     

马血中SOD提取液膜浓缩工艺研究

确立SOD提取液膜浓缩的工艺条件。用不同孔径的膜过滤马血SOD提取液,研究提取液膜浓缩和污染膜清洗工艺条件。结果表明,适用于SOD提取液浓缩的超滤膜为截留分子量10 kDa的RC膜,操作压力0.20 MPa,料液温度20℃,流速53.5 m/s,在此条件下浓缩最佳倍数为2。污染膜清洗的最适清洗剂为2%柠檬酸和0.3%NaOH+0.1%H2O2、清洗时间40 min、清洗温度35℃,该条件下膜恢复率为94.12%。在此条件下,SOD活力处于较高的水平,并及时解决膜污染带来的膜通量下降问题。     

陶瓷膜过滤性能的影响因素

研究了氯化钠盐水温度、盐水中固含量和陶瓷膜孔径对陶瓷膜过滤器过滤性能的影响,结果显示:盐水中含固质量分数在2％～22％变化时,陶瓷膜通量无明显变化;盐水温度升高,膜通量增大,但对颗粒物截留效果无明显影响;10 nm孔径的陶瓷膜通量较40、50 nm孔径的陶瓷膜通量小,陶瓷膜对颗粒物A(粒径5～40 μm)和B(粒径0....     

膜生物反应器中膜污染机理的研究

在采用膜生物反应器（MBR）处理染料废水的过程中,通过对活性污泥进行终端过滤来反映膜污染机理,着重考察了膜过滤的形式、膜通量变化和膜污染的形成。污泥的终端过滤过程严格符合沉积过滤定律;膜通量随过滤时间呈指数衰减趋势,并在几分钟内就达到相对稳定值;扫描电镜照片也证实了膜污染主要是膜面沉积层引起的。     

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。