沸石固定化细胞降解氰化物的初步研究

从污染土壤分离出一株高效降氰菌0205301,将该菌株的细胞固定在沸石载体上,细胞具有机械强度高、可重复使用、与产物易分离等优点.对固定化细胞降解CN-质量浓度为50mg/L的废水进行了研究,得出了反应最佳条件为温度30℃、pH8.0、反应时间6h,CN-降解率达到99.4%.     

固定化细胞生物反应器处理含氰废水

将产碱杆菌Alcaligenes sp.DN25固定在聚氨酯泡沫载体上构成固定化细胞反应器,进行连续处理含氰废水研究.实验结果表明,反应器能够高效且稳定地处理含氰废水,有很好的氰负荷适应性,水力停留时间HRT和pH值对反应器氰去除率有一定影响,反应器运行前40 d降解率维持在90%;运行的40～60 d,系统中加入氨氮离子后,反应器对氰化物的降解率明显下降,仅85%左右,我们认为是氨氮连续加入和产物HCOOH的生成引起系统缓冲能力下降,使得pH显著降低而造成.     

丝瓜瓤固定黄孢原毛平革菌对2,4-二氯酚的降解研究

利用植物载体丝瓜瓤对黄孢原毛平革菌进行固定,研究了固定化细胞对2,4-二氯酚的降解性能。利用固定化细胞流化床反应器连续处理质量浓度为20mg/L的2,4-二氯酚废水。考察了不同水力停留时间对处理效果的影响。结果表明,采用吸附生长法能有效实现黄孢原毛平革菌的固定,固定细胞量可达0.791g[细胞]/[丝瓜瓤]。固定化细胞最适降解温度和pH值分别为35℃、6.0。对于质量浓度在20mg/L以下的低浓度2,4-二氯酚,固定化细胞和游离细胞的降解速率相当;对于质量浓度在50～120mg/L的高浓度2,4-二氯酚,固定化细胞具有明显优势,不仅可以耐受更高浓度的2,4-二氯酚,其降解速率也高于游离细胞,最大降解速率是13.95mg/(L·d),是游离细胞的2倍。不同的水力停留时间对固定化细胞流化床反应器连续处理2,4-二氯酚的降解效率有很大影响,固定化细胞对2,4-二氯酚降解过程遵循Monod方程。     

高效降氰真菌的分离筛选及降氰条件研究

从电镀废水、含氰污泥及电镀车间渡槽液中分离筛选出三株高效降氰真菌,并对其中Fw菌株氰化物降解条件进行了研究。研究结果表明,该菌株的最佳降氰条件为温度20-30℃、pH5-7、摇床转数100～180r／min、接种量6％-20％。在最佳降氰条件下,Fw菌株降氰率达到95％以上,剩余氰化物质量浓度低于1mg／L。该菌株可以直接利用CN-作为碳源和氮源,并且在培养基中不外加碳源和氮源时,氰化物剩余质量浓度分别为0．25mg／L和0．49mg／L,达到国家一级排放标准。本研究结果可以作为利用真菌处理含氰废水的依据。     

固定化铜绿假单胞菌GF31对氯氰菊酯降解的强化作用

研究了沸石固定化铜绿假单胞菌GF31的氯氰菊酯降解特性及强化修复效果。综合考虑氯氰菊酯特性及其传质等因素,选择沸石为载体进行固定化,电镜扫描结果显示,菌株GF31能较好地生长于沸石载体孔隙中。固定化后菌株GF31的去除率和比降解速率提高,6 d对100 mg·L^-1氯氰菊酯的去除率由37%提高至61.4%,游离细胞和固定化细胞对于300 mg·L^-1的氯氰菊酯的平均比降解速率分别为487和917 mg·[L·d·(g细胞干重)]^-1。固定化细胞对pH和高浓度氯氰菊酯的耐受性显著增强,在pH 10或者菊酯浓度为800 mg·L^-1时仍能保持一定的降解活力。投加固定化细胞对实际土壤进行生物强化修复,其降解过程可用一级动力学方程来描述。与自然降解相比,氯氰菊酯的半衰期t_1/2由34.3 d缩短至8.02 d,显示出固定化细胞良好的强化修复效果。     

苯酚降解菌的固定化及其降解特性的研究

以海藻酸钠为载体,对苯酚降解菌进行细胞固定化,并对其降解特性进行了研究。通过单因素实验确定较佳的固定化条件为:海藻酸钠质量浓度3.0%、CaCl2质量浓度4.0%、湿菌体量0.4 g/10 mL海藻酸钠溶液;固定化细胞降解苯酚的最适条件为:温度30℃、pH值7.0、NaCl质量浓度低于2.5%,该菌株固定化细胞的降解苯酚能力和耐受苯酚能力均大于游离细胞,800 mg.L-1苯酚降解48 h,降解率可达99%以上。     

固定化活细胞苯酚生物降解特性研究

从活性污泥中分离得到1株苯酚降解能力较强的菌株,16S rRNA基因序列分析表明,该菌属于不动杆菌属(Acinetobactersp.)。通过不同的方式将细菌细胞固定后,与自由悬浮细胞比较,分析其苯酚生物降解特性,结果表明,在苯酚初始质量浓度为700 mg/L、培养时间为25 h的条件下,游离细胞和固定化活细胞的苯酚降解率均超过90%;与自由悬浮细胞相比,固定化细胞的降酚能力、耐酚能力以及环境耐受能力均强于游离细菌。比较细菌细胞不同固定方式对苯酚降解性能的影响,结果发现,将细胞固定在纱布上的可操作性及处理效果均优于海藻酸钠小球,且固定化细胞的机械强度随着培养基中pH的减小而增加,研究结果对含酚工业废水的生物处理具有重要的实际意义。     

Fe-C@CNTs球团降解含氰废水

含氰废水对生物和环境危害极大,其排放标准越来越严格。介绍了铁碳微电解法降解含氰废水工艺,考察了Fe-C@CNTs球团、Fe-C球团与铁屑对含氰废水降解率的影响,实验结果表明Fe-C@CNTs球团处理含氰废水更为高效。Fe-C@CNTs球团处理含氰废水时最佳质量浓度为100 g/L、最佳反应时间为40 min,在此条件下,Fe-C@CNTs球团对含氰废水的降解率高达83. 3%。     

聚氨酯泡沫固定化Alcaligenes sp.DN25去除苯酚的研究

载体材料是构建固定化体系的基础,其中孔结构直接影响固定化的生物量及降解结果,开展了制备不同孔径聚氨酯泡沫材料并考察其固定化产碱杆菌DN25降解苯酚的研究。结果表明,孔隙结构的聚氨酯泡沫材料在孔径均值为150 μm时所固定的生物量达到最大值（0.0253±0.0010） g,固定化细胞能在48 h内完全降解1160 mg·L^-1苯酚,而游离细胞则完全受到抑制,并且发现载体材料PUF在降解前12 h内吸附苯酚的平衡吸附率为56.1%。进一步研究固定化细胞在初始pH6.0~9.0,NaCl浓度0~4.0%条件下降解900 mg·L^-1苯酚的情况,固定化细胞对苯酚的去除率受pH、NaCl浓度的影响不显著。并且,固定化细胞重复使用11个批次对500 mg·L^-1苯酚的去除率仍能保持100%,反映了PUF-固定化细胞体系对苯酚处理浓度和系统稳定性两方面的强化作用。     

苯酚高效降解菌固定化小球的制备及其降解条件研究

对采自某印刷厂的污泥进行驯化、富集、筛选,得到一株以苯酚为唯一碳源生长的高效苯酚降解菌,并以海藻酸钠为载体对该苯酚高效降解菌进行固定化包埋,并通过正交试验确定了制备固定化小球的最佳条件,研究表明,固定化的该高效苯酚降解菌在对苯酚的降解率与对苯酚的耐受程度均高于游离细胞,经30 h,1 200 mg/L的苯酚可以完全降解,固定化降解苯酚的最适温度范围30~35℃,最适pH范围为7~9,最适摇床转数为120~150 r/m in。     

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。