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1.
采用简单的乙醇分散法制备了纳米羟基铁(nFeOOH)改性活性炭(AC)复合材料(nFeOOH@AC),并考察其对饮用水中Cd(Ⅱ)的吸附性能。结果表明,nFeOOH以100~500 nm的粒径均匀分布在AC表面及孔道上。相比AC,nFeOOH@AC对Cd(Ⅱ)的去除率提高了2.1倍。同时,Langmuir吸附模型及准2级反应动力学模型可以很好的描述nFeOOH@AC对Cd(Ⅱ)的吸附过程,其最大吸附量和反应速率常数分别为29.8 mg/g和8.52 mg/(g·min)。Cd(Ⅱ)的吸附过程具有pH依赖性且载铁稳定性强。吸附后的nFeOOH@AC可用醋酸脱附,且失效的nFeOOH@AC经1mol/L的HCl洗脱并重新负载nFeOOH后,再生率可达93.5%。因此,nFeOOH@AC具备良好的重复利用和再生性能。 相似文献
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用微波辐射制备无机复合吸附剂。将该吸附剂进行含磷废水的吸附试验,研究了静态吸附的动力学、热力学和再生条件。结果表明:该吸附剂对磷酸根的吸附符合一级反应动力学;平衡浓度与吸附容量符合Freundlich吸附等温线。失活的吸附剂在低的碱性溶液中很容易再生,解吸率可达98%,活化率为99%。 相似文献
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研究了新型吸附材料Zn-MOF-74对水体中重金属Cd(Ⅱ)的吸附性能和吸附机理。结果表明,吸附过程较好地符合Langmuir模型、Temkin模型、D-R模型和准二级动力学模型,最大吸附量为16.77 mg/g;吸附过程为物理吸附和化学吸附共同作用,且为自发的放热反应。采用Zn-MOF-74处理0.5 mg/L的含镉废水,有效时长可达36.25 h,Cd(Ⅱ)去除率>90%;NaCl溶液的解吸率可达到85%。吸附位点主要集中在孔道中,有静电作用、化学作用和氢键作用。 相似文献
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纳米腐植酸对镉离子的吸附热力学及动力学 总被引:1,自引:0,他引:1
研究了采用碱溶酸析法配加高剪切技术制备的纳米腐植酸对重金属镉离子的吸附性能,用原子力显微镜(AFM)、红外光谱(FT-IR)、扫描电子显微镜(SEM)、比表面积测试仪(BET)等对纳米腐植酸进行表征,绘制了静态平衡吸附等温线及吸附动力学曲线。实验结果表明:吸附剂纳米腐植酸对镉离子的吸附较符合Freundlich模型,在288~308 K温度下,吸附焓变?H=24.22 k J?mol?1,表明吸附是吸热过程,吸附动力学符合HO二级吸附速率方程,反应的表观活化能Ea=25.58 k J?mol?1,表明纳米腐植酸对重金属离子的吸附是化学反应控制,而非扩散所控。吸附剂纳米腐植酸解吸再生循环使用5次后,Cd2+的吸附容量仅减少18.9%,说明该吸附剂具有较好的解吸再生性能。 相似文献
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采用丙烯酸接枝改性聚丙烯非织造布(PP-g-AA)对阳离子红X-GRL染料进行吸附与解吸,探讨了PP-g-AA对染料的吸附动力学机理、解吸过程和解吸动力学机理,以及基于动态吸附的过滤分离操作,分析了PP-g-AA对染料吸附-解吸再生循环利用的可行性。结果表明:不同初始染料浓度下,PP-g-AA的吸附动力学符合Lagergren's准二级动力学模型和双指数模型;解吸液的最佳配比为表面活性剂质量分数5%,乙醇与水的体积比3∶7,解吸率随吸附量的增大呈现先增大后减小的趋势,解吸符合Lagergren's准二级动力学模型;动态吸附-解吸再生循环10次后,染料的去除率达96%以上,再生循环8次时,PP-g-AA的跨膜压力为37.1 k Pa,水通量最大达38.6 L/(m2·h)。 相似文献
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《水处理技术》2017,(9)
利用遗态转化工艺制备获得桉树遗态结构HAP/C复合材料(PBGC-HAP/C),将其用于含Cd(Ⅱ)模拟废水的吸附净化处理,研究了p H、初始含量、投加量、吸附剂粒径和吸附剂种类对Cd(Ⅱ)吸附的影响,并且进行了材料吸附前后进行X射线衍射仪、傅里叶变换红外光谱仪表征和吸附机理探讨。结果表明,对50 m L含Cd(Ⅱ)模拟废水,当pH为5、初始Cd(Ⅱ)质量浓度为5 mg/L、PBGC-HAP/C投加量为0.1 g时,吸附平衡时间为120 min,去除率可达97.88%。Langmuir等温模型和准2级动力学模型更适合描述该吸附过程;材料表面Cd~(2+)取代了部分钙离子位置,表面基团与Cd~(2+)发生络合反应,吸附过程主要以单分子层化学吸附为主,该反应为吸热反应,升高温度有利于吸附进行。 相似文献
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以毛蕨为基体,研制的新型磁性生物吸附剂(CMJ),并对其进行表征、Cd(Ⅱ)吸附动力学与热力学研究、模拟灌溉水处理研究。结果表明,CMJ吸附剂具有良好的吸附能力,吸附过程是自发、吸热的,吸附等温线符合Langmuir模型,吸附动力学符合拟二级模型。温度为20℃、30℃、40℃和50℃时,CMJ对Cd(Ⅱ)最大吸附容量分别为40.8、49.4、54.6和56.6 mg/g,并有优异的循环性能和再生性。灌溉水镉处理研究表明,处理量为200 m L,灌溉水中Cd(Ⅱ)去除率为99.1%。因此,CMJ可应用于灌溉水中Cd(Ⅱ)的处理。 相似文献
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以甲基丙烯酸和丙烯酰胺为功能单体,通过悬浮聚合法制备了氨基和羧基双功能化的磁性复合微球(Fe3 O4@SiO2-NH2/COOH),并探讨了其对水溶液中Cd(Ⅱ)和Pb(Ⅱ)的吸附性能.X-射线衍射(XRD)分析表明,制备的磁性吸附剂内核为Fe3 O4.红外光谱(FT-IR)和扫描电镜(SEM)测试表明,氨基和羧基对Fe3 O4@SiO2表面改性成功.吸附试验显示,Fe3O4@SiO2-NH2/COOH吸附Cd(Ⅱ)和Pb(Ⅱ)的最优pH值分别为5.0和5.5,吸附过程均符合动力学准二级模型和Langmuir吸附等温模型,吸附剂对Cd(Ⅱ)和Pb(Ⅱ)最大吸附量分别为207.807 mg/g和168.995 mg/g.实际饮用水样中Cd(Ⅱ)和Pb(Ⅱ)的吸附表明,去除率分别可达97.74%和91.44%.该磁性吸附剂对两种重金属离子吸附量大、去除率高,具有良好的实际应用潜力. 相似文献
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文章研究了浮游球衣菌-纳米Fe3O4生物吸附剂对重金属离子Cd(Ⅱ)和Cr(Ⅵ)的吸附性能,结果表明,此生物吸附剂对Cd(Ⅱ)和Cr(Ⅵ)有一定的吸附作用,当处理废水的pH为5.5、菌体投加量为0.3 g·L-1时,对20 mg·L-1含Cd(Ⅱ)和Cr(Ⅵ)废水的去除率分别为89%和68%。吸附-解吸试验结果显示,生物吸附剂可重复利用3次,在使用第3次时,Cd(Ⅱ)和Cr(Ⅵ)的去除率仍可达64%和42%。 相似文献
10.
在室温条件下,通过戊二醛交联法制备得到壳聚糖/Fe3 O4(CS-Fe3 O4).采用FT-IR、XRD、SEM、VSM以及TGA等手段对合成材料进行表征,并系统考察了CS-Fe3 O4的吸附性能.结果表明:CS-Fe3 O4吸附水中茜素红S(ARS)时,在300 min内可以达到吸附平衡,在反应温度为313 K时最大吸附容量可达976.3 mg/g,整个吸附过程符合准二级动力学和Langmuir等温模型,经过5次吸附/解吸循环后,吸附剂对ARS的吸附容量仍然可达416.2 mg/g. 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
17.
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. 相似文献
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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. 相似文献
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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. 相似文献
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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。 相似文献