生物滴滤法净化VOCs气体的研究进展

生物滴滤法净化VOCs气体是一种经济有效的废气处理方法,介绍了生物滴滤法净化VOCs气体的研究进展,重点阐述了生物滴滤法的工艺特点、生物滴滤法净化VOCs研究现状和影响净化效率的因素等内容,并提出发展生物滴滤技术的建议和研究方向。     

海上油田伴生气生物滴滤净化技术研究进展

介绍了国内外针对油田伴生气开采利用现状,从合成生物学角度出发,阐述构建微生物菌群净化体系的技术思路,综述了生物滴滤技术的综合应用与效果,为完善生物滴滤技术净化油田伴生气提供多样化治理视角与合理净化体系。     

生物法净化处理工业废气的研究进展

随着世界范围内环境污染的加剧,环境问题引起了强烈的重视,尤其是大气污染,成为了大众关注的焦点。在空气污染治理中,生物法净化工业废气具有高效、低成本等优点,成为目前研究的热点。本文介绍了生物法净化处理废气的基本原理,主要包括生物膜理论中的传质和降解过程,阐述和比较了生物滤池、生物洗涤和生物滴滤这3种处理工艺,分析了影响生物法处理废气的重要因素,如填料、营养物、微生物、压降。同时对国内外发展现状进行了详细评述,与国外研究相比,特别是在污染物种类的研究上还有一定差距。生物滴滤工艺相对研究的较晚,提出今后研发重点和方向,将生物滴滤工艺全面推向工业化,加强对降解微生物的深入研究,实现单种到多种污染物的降解。     

基于混菌体系生物滴滤系统净化甲苯废气的研究

以纳米活性陶瓷球为生物滴滤塔填料,利用基因工程改造大肠杆菌和铜绿假单胞菌为底盘菌进行挂膜,结合物理吸附开展生物滴滤系统净化甲苯废气的研究。结果表明,混菌体系在含甲苯培养基中生长良好,且大肠杆菌与铜绿假单胞菌不形成竞争,二者相互利用、相互促进;当生物滴滤系统运行96 h时,生物滴滤塔去除率可达96.7%,总去除率可达97.2%。     

硅油对生物滴滤塔处理邻二甲苯废气的影响

研究了硅油对生物法处理有机废气的强化效果。在摇床实验中考察了硅油对邻二甲苯的增溶效果,及其对微生物降解活性的影响情况。结果表明硅油对邻二甲苯有明显的增溶效果且对微生物的活性无影响。在生物滴滤塔挂膜稳定后,考察了加入5%硅油后邻二甲苯在生物滴滤塔中的去除效率变化。相同实验条件下,当进气浓度在600 mg·m-3左右时,硅油可以使邻二甲苯的去除效率明显增加。研究结果显示,添加硅油的生物滴滤塔在去除邻二甲苯废气方面效率更高,去除效率比普通生物滴滤塔高10%左右。根据以上实验结果可以得出结论,硅油能有效提高生物法处理邻二甲苯废气的效果。     

生物法处理挥发性有机废气（VOCs）的研究

生物法处理挥发性有机废气是近年来逐步发展起来的一项废气治理新技术,具有效率高、投资及运行费用低、无二次污染、安全性好等优点。文章主要概述了有机废气生物处理的3种主要形式：生物过滤池、生物滴滤塔和生物洗涤器的原理、流程以及研究进展,比较了以上3种反应器的优缺点,并提出了现存问题和将来的研究方向。     

生物滴滤塔净化处理硫化氢的实验研究

在常温条件下,以陶粒和悬浮改性填料WD-F10-4为填料的生物滴滤塔系统对硫化氢废气进行净化处理,考察了不同硫化氢负荷、营养液喷淋量和气体停留时间对生物滴滤塔性能的影响。实验结果表明,当进气质量浓度为400 mg/m3,硫化氢负荷为32 g/(m3·h),喷淋量为4 L/h,气体停留时间为46 s,系统的平均去除效率为97%。系统运行期间,填料未出现堵塞现象,证明悬浮改性填料可用作生物滴滤塔的填料。     

生物滴滤塔处理低浓度氮氧化物

采用活性炭填料挂膜的生物滴滤塔净化低浓度氮氧化物废气,研究结果表明,生物净化效率可达99%。适宜的喷淋量为3L/h,适宜的气体流量为0.4～0.5m3/h。当气体流量在0.56m3/h,入口气体氮氧化物浓度为480mg/m3,停留时间18.4s时,氮氧化物的净化效率可达到96.67%。净化氮氧化物的反硝化菌大部分为副球菌属(Paracoccus)中的细菌,也有小部分硫杆菌属(Thiobacillus)中的细菌。活性炭生物净化氮氧化物废气主要发生在活性炭外表面,而活性炭内表面发生的生化反应很少。     

生物滴滤塔在处理市政恶臭中的应用

市政恶臭污染已成为严重的环境污染问题,对其治理也成为近几年研究的热点。生物法中的生物滴滤法因其压降小、不易堵塞、易调控、适用范围广等特点在市政恶臭处理中得到广泛应用。文章介绍了生物滴滤塔概况,包括生物滴滤塔除臭技术原理和工艺流程,详细阐述了影响生物滴滤塔处理恶臭的重要因素,如生物填料、微生物菌种、运行参数及运行环境条件等;并例举了近几年应用生物滴滤塔处理市政恶臭的工程实例,最后提出其未来研究发展方向。     

生物技术在挥发性有机废气净化中的应用

生物技术是近年发展起来的挥发性有机废气净化新技术.文章介绍了国内外这方面的应用进展、主要处理工艺设备及其性能特征.概述了生物滴滤塔处理挥发性有机废气的影响因素的选择,同时指出了存在的主要问题和今后的研究方向.     

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。