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1.
磷酸活化烟草杆制备中孔活性炭的研究   总被引:10,自引:0,他引:10  
以烟草杆为原料,以磷酸为活化剂,采用一步炭化法制备了活性炭。采用正交实验研究了磷酸质量分数、浸渍时间、炭化温度及保温时间对活性炭得率和吸附性能的影响,在最佳工艺条件(磷酸质量分数30%,浸渍时间48 h,炭化温度750℃,保温时间20 min)下,所制备的活性炭其碘吸附值为889.36 mg/g,亚甲基蓝吸附值为21.5 mL/(0.1 g),得率为36.90%。同时测定了该活性炭的液氮吸附等温线,并通过BET、H K方程、D A方程和密度函数理论(DFT)表征了活性炭的孔结构。结果表明,该活性炭为中孔型,BET比表面积为892 m2/g,总孔体积为0.467 8 mL/g,微孔占总孔体积的37.06%,中孔占62.85%,大孔占0.07%。最后采用电子探针和透射电镜分析了活性炭的微观结构,其结构与氮吸附测定的结果较为一致。  相似文献   

2.
微波辐射亚麻屑制活性炭的研究   总被引:5,自引:0,他引:5  
以亚麻屑为原料,采用微波辐射氯化锌法制备活性炭。研究了浸渍时间、氯化锌浓度、微波功率和辐射时间等因素对活性炭吸附性能和得率的影响。确定了用亚麻屑制备活性炭的最佳工艺条件:亚麻屑15g、浸渍时间24h、氯化锌浓度20%、微波功率600W、辐射时问12min。在该工艺条件下制备的活性炭其碘吸附值为1071.3mg/g、亚甲基蓝吸附值165mL/g、得率可达37.1%,均超过了国家标准一级产品的指标,且该工艺所需炭化活化时间为传统方法的1/30。  相似文献   

3.
以核桃壳为原料,采用微波加热-水蒸汽活化法制备了活性炭。研究了微波功率、活化时间和水蒸汽流量等因素对吸附性能的影响。最佳工艺条件为:微波功率600 W、活化时间7 min、水蒸汽流量5 mL/min,活性炭产品的碘吸附值1076.57 mg/g,亚甲基蓝吸附值195 mg/g,得率25.11%。该工艺将常规加热方法的炭化和活化简化为一个过程,所需加热时间仅为传统方法的1/21,产品活性炭的亚甲基蓝吸附值为国家一级品标准的1.44倍。同时测定了该活性炭的氮吸附等温线,通过BET计算了活性炭的比表面积,并通过H—K方程和密度函数理论表征了活性炭的孔结构。结果表明,该活性炭为微孔型,BET 比表面积1 154.91 m~2/g,总孔体积0.564 9 mL/g,微孔占总孔体积(体积分数,下同) 79.86%,中孔体积分数19.97%,大孔占0.17%。  相似文献   

4.
以亚麻屑为原料,采用微波辐射氯化锌法制备活性炭。研究了浸渍时间、氯化锌浓度、微波功率和辐射时间等因素对活性炭吸附性能和得率的影响。确定了用亚麻屑制备活性炭的最佳工艺条件:亚麻屑15g、浸渍时间24h、氯化锌浓度20%、微波功率600W、辐射时间12min。在该工艺条件下制备的活性炭其碘吸附值为1071.3mg/g、亚甲基蓝吸附值165mL/g、得率可达37.1%,均超过了国家标准一级产品的指标,且该工艺所需炭化活化时间为传统方法的1/30。  相似文献   

5.
研究了以烟秆废弃物为原料,木焦油为主的复合黏结剂,采用微波辐射二氧化碳法制备颗粒活性炭的可行性.系统探索了微波功率,活化时间以及二氧化碳流量对颗粒活性炭吸附性能和产率的影响,得到了微波辐射二氧化碳法制备颗粒活性炭的最佳工艺条件:微波功率700W,活化时间70min,二氧化碳流量0.15L/min.用此工艺条件制得的颗粒活性炭,碘吸附值为960.30mg/g,亚甲基蓝吸附值13mL/0.1g,产率为43.37%.同时,测定了该颗粒活性炭氮气吸附,通过BET法计算了活性炭的比表面积,并通过DFT表征了活性炭的孔径结果.结果表明,该活性炭为微孔型,BET比表面积为986.65m^2/g,总孔容为0.5152mL/g.  相似文献   

6.
探讨了活化温度、活化时间、水蒸气流量对再生后活性炭吸附性能和得率的影响,得到了最佳工艺条件:活化温度1 000℃,活化时间60 min,水蒸气流量2.23 g/min。该工艺条件下再生活性炭的碘吸附值1 174.37 mg/g,亚甲基蓝吸附值200 mL/g,得率为62.87%。再生后活性炭的吸附指标达到国家一级品的标准,其中亚甲基蓝吸附值是国家一级品标准的2.22倍。同时,测定了该活性炭氮吸附,通过BET计算了活性炭的比表面积,通过密度函数理论(DFT)表征了活性炭的孔结构。结果表明:该活性炭为微孔型,BET比表面积为1 254.51 m2/g,总孔容为0.592 6 mL/g。  相似文献   

7.
添加FeCl3改性污泥活性炭吸附Cu2+研究   总被引:1,自引:0,他引:1  
以城市污水厂污泥为原料,以氯化锌为活化剂,添加FeCl3改性制备活性炭,用以吸附模拟废水中的Cu^2+离子。研究表明:最佳制备条件是活化温度700℃,ZnCl3浓度5mol/L,活化时间60min和FeCl3添加量10%,其污泥炭样品多点BET比表面积为163.853m^2/g,平均孔半径为5.28nm。污泥活性炭吸附最优操作条件为温度20℃,pH值为6.0,Cu^2+初始浓度越高,吸附量越大,在Cu^2+初始浓度388.064mg/L下的吸附量可达20.6mg/g。通过BET比表面积测试,活性炭表面积为163.85m^2/g。  相似文献   

8.
微波辐射-水蒸气法制备烟杆基颗粒活性炭   总被引:11,自引:1,他引:10  
研究了以烟杆废弃物为原料,炭化过程中所产生的木焦油为主的复合粘结剂,采用微波辐射-水蒸气法制备颗粒活性炭的可行性。探讨了微波功率、活化时间以及水蒸气质量流量对颗粒活性炭吸附性能和得率的影响。得到了微波辐射-水蒸气法制备颗粒活性炭的最佳工艺:微波功率700 W,活化时间40 m in,水蒸气质量流量1.70 g/m in。此工艺条件制得的颗粒活性炭,碘吸附值1 060.81 mg/g,亚甲基蓝吸附值175 mL/g,得率30.83%。同时,测定了该颗粒活性炭氮吸附,通过BET法计算了活性炭的比表面积,并通过DFT表征了活性炭的孔结构。结果表明:该活性炭为微孔型,BET比表面积为1 109.22 m2/g,总孔容为0.613 1 mL/g。  相似文献   

9.
以氯化锌浸渍的木屑为原料,黏土为粘结剂,制备炭陶复合吸附材料。讨论了炭化温度和保温时间对其吸附性能的影响,并对其孔隙结构进行了表征。结果表明,随温度和保温时间的增加,炭陶复合吸附材料的碘吸附值和亚甲基蓝吸附值呈先上升后下降的趋势;木屑受到活化作用形成活性炭而发生收缩,在活性炭和陶土之间形成空隙,有利于形成孔隙结构发达的炭陶复合吸附材料。在温度500℃、保温时间1 h的较佳工艺条件下,制得炭陶复合吸附材料的比表面积为809.5 m2/g,总孔容积为0.298 cm3/g,中孔容积为0.185 cm3/g,微孔容积为0.113 cm3/g,炭陶的含炭量为60.7%,碘吸附值为680.5 mg/g,亚甲基蓝吸附值为165.0 mg/g。  相似文献   

10.
以丝瓜络为原料,经氯化锌活化丝瓜络制备微孔活性炭。通过设计正交实验,考察了不同因素氯化锌浓度、活化温度、活化时间和浸泡时间对所制备活性炭吸附性能的影响。结果表明:最佳工艺条件为活化剂浓度40%、活化温度450℃、活化时间60 min和浸泡时间12 h。在此条件下制备的活性炭孔径分布窄,为多微孔、无定形活性炭,BET比表面积达1 020 m2/g,其吸附碘值、亚甲基蓝值分别达到819.45 mg/g、165.43 mg/g,是一种廉价且吸附性能高的吸附材料。  相似文献   

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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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14.
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   

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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   

18.
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   

19.
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   

20.
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   

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