Fe~0可渗透反应墙处理地下水污染的研究现状与展望

阐述了Fe⁰可渗透反应墙(permeable reactive barrier,PRB)技术在处理污染物时可能发生的反应机理及研究现状,主要介绍了零价铁的吸附共沉淀作用、电化学腐蚀作用、化学还原以及生物还原作用。同时指出零价铁作为填料的不足之处,并且展望了PRB技术今后的研究方向。     

Fe~0可渗透反应墙处理地下水污染的研究现状与展望

阐述了Fe~0可渗透反应墙(permeable reactive barrier,PRB)技术在处理污染物时可能发生的反应机理及研究现状,主要介绍了零价铁的吸附共沉淀作用、电化学腐蚀作用、化学还原以及生物还原作用。同时指出零价铁作为填料的不足之处,并且展望了PRB技术今后的研究方向。     

PRB技术修复地下水污染的研究现状

介绍地下水修复技术的分类,论述可渗透反应墙技术的原理和结构,综述了当前国内外可渗透反应墙技术的应用情况,最后指出该技术当前存在的问题。     

PRB技术修复地下水污染物的研究综述

综述了可渗透反应墙的概念,按照处理不同的污染物和反应介质对PRB进行分类,并对此研究现状进行分析,分析当前PRB技术在修复地下水污染所遇到的问题。     

可渗透反应墙反应材料研究进展

可渗透反应墙(PRB)技术是一种经济高效的被动地下水污染原位修复技术,被认为是最有潜力的地下水处理技术之一.污染地下水流经PRB墙体时,污染物被墙体内的反应材料截留或降解,实现污染物的去除,因此,PRB材料的研发是该技术的研究热点.迄今为止,基于种类众多的反应材料,PRB已被成功用于多种污染物的去除.本文在分类阐述PR...     

PRB修复重金属污染地下水的反应介质研究进展

可渗透反应墙(permeable reactive barrier,PRB)技术作为一种经济、简易、高效的原位被动修复技术逐渐被广泛研究和应用。其关键技术是反应介质的研究,修复重金属污染地下水的PRB反应介质材料细分为氧化还原反应介质、吸附反应介质、沉淀反应介质和混合反应介质等四类,对反应介质的去除机理、应用现状和存在问题进行了综述。可渗透反应墙介质材料的选择应在其反应机理的基础上,结合当地水文地质条件、污染特征和经济费用等加以综合考虑,以保证PRB的长效性。未来PRB反应介质的发展主要集中于复合介质和新型反应介质的开发、反应介质的性能研究。同时,我国对PRB修复重金属污染地下水反应介质的研究还处于实验阶段,应进一步加强工程应用。     

PRB修复重金属污染地下水的反应介质研究进展

可渗透反应墙(permeable reactive barrier,PRB)技术作为一种经济、简易、高效的原位被动修复技术逐渐被广泛研究和应用。其关键技术是反应介质的研究,修复重金属污染地下水的PRB反应介质材料细分为氧化还原反应介质、吸附反应介质、沉淀反应介质和混合反应介质等四类,对反应介质的去除机理、应用现状和存在问题进行了综述。可渗透反应墙介质材料的选择应在其反应机理的基础上,结合当地水文地质条件、污染特征和经济费用等加以综合考虑,以保证PRB的长效性。未来PRB反应介质的发展主要集中于复合介质和新型反应介质的开发、反应介质的性能研究。同时,我国对PRB修复重金属污染地下水反应介质的研究还处于实验阶段,应进一步加强工程应用。     

我国垃圾填埋场地下水原位修复技术研究

垃圾填埋场渗漏造成的地下水污染具有掩蔽性且污染物种类较多,修复治理难度较大,原位修复技术以其处理方便、对环境扰动小、修复效果好等优势,在垃圾填埋场地下水修复中具有广阔的应用前景。本文重点介绍了几种垃圾填埋场地下水污染原位修复技术：包括可渗透反应墙(PRB)技术、电动修复(EK)技术、生物修复技术、原位注射修复技术和监控自然衰减(MNA)技术,以期为垃圾填埋场地下水污染的修复提供参考依据。     

纳米级金属铁还原脱氯技术的改进研究

零价铁处理环境中有机卤化物、重金属等污染物是目前公认的一种有效的环境修复技术,具有良好的应用前景。但无论是金属铁可渗透反应墙还是铁纳米颗粒原位注射技术都存在缺陷,对零价铁反应性能的改进十分迫切。文章综述了国内外对零价铁反应性能改进的研究进展,详细介绍了当前最热门的铁纳米颗粒负载技术及铁纳米颗粒分散稳定技术对零价铁反应性能的改进机理及优势,指出了目前研究存在的一些问题,并对零价铁技术修复环境的工程应用提出了展望。     

组合材料应用于可渗透反应墙技术的研究进展

因暴露于农业和工矿业等来源的各类污染物，地下水资源受到严重威胁。可渗透反应墙（Permeable reactive barrier,PRB）是一种地下水污染原位修复的创新技术，该技术的关键在于选取适宜的墙体反应介质，如广泛研究的零价铁（ZVI）、碳材料、沸石等。介绍了PRB技术的原理、介质材料类型与选取所需考虑的因素；回顾了含铁、含碳和含硅（矿物）组合材料应用于PRB修复地下水污染的研究进展，并聚焦了批量实验和柱试验中目标污染物的去除效果及作用机理。通过固定、表面修饰与混合等方式，组合材料在一定程度上可解决ZVI的聚集或表面钝化现象，并新增作用机制以助力污染物的去除；通过改性或混合等形式，组合材料还可增强含碳或含硅（矿物）材料对某些特定污染物的去除性能。最后，还展望了未来PRB技术中组合材料的开发和应用方向，以期为研发长效和环境友好型PRB反应介质提供参考。     

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。