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1.
系统研究了油页岩渣合成沸石过程中NaOH浓度、熔融温度、晶化时间、晶化温度对沸石生成及其Cr6+吸附性能的影响. 结果表明,NaOH浓度和晶化时间主要影响沸石的种类;沸石对Cr6+的吸附率随其制备的熔融温度、晶化时间、晶化温度的增加有增大的趋势,但随NaOH浓度降低而增加;沸石对1 mg/L含铬模拟废水中Cr6+的最大吸附量为1.120 mg/g,吸附率达到89.6%. 考虑到成本,最佳合成条件为:NaOH浓度4.6 mol/L,熔融温度400℃,晶化时间72 h,晶化温度140℃.  相似文献   

2.
赤泥是制铝工业提取氧化铝时排出的污染性废渣.以赤泥为原料合成沸石分子筛,考察合成分子筛去除氨氮的效果,实现"以废治废"的目的.系统分析了Si/Al比、Na/Si比、陈化时间、晶化温度和晶化时间等参数对合成沸石分子筛及其对相应水溶液中氨氮去除率的影响.结果表明:合成制备分子筛的最佳条件为Si/Al比、Na/Si比、陈化时间、晶化温度和晶化时间的最佳合成条件分别为4.5、1.3、10 h、120℃和16 h.与原赤泥相比,合成的沸石具有较好的吸附性能,在最佳实验条件下,氨氮去除率由6.31%提高到42.86%.合成分子筛是废水中氨氮去除的有效吸附材料.  相似文献   

3.
《硅酸盐学报》2021,49(7):1429-1438
以风化花岗岩洗砂尾泥为硅铝源,通过水热法制备4A沸石用于处理氨氮污染。通过不同煅烧温度的表征确定尾泥活化最佳温度为600℃,并在单因素实验基础上,以阳离子交换容量(CEC)为响应值,根据中心组合设计–响应面优化法实验设计原理对水钠比、钠硅比、晶化温度、晶化时间等参数进行优化,发现晶化时间对阳离子交换容量影响最大,确定最优工艺参数为:n(H_2O):n(NaO_2)=1.42;n(NaO_2):n(SiO_2)=61.0;晶化温度为90.89℃;晶化时间为8.16 h,此时阳离子交换容量最大为198.5 mmol/100 g。用扫描电子显微镜、X射线衍射对合成4A沸石进行表征,最优工艺参数下所得4A沸石纯度较高。静态吸附实验,pH=4,固液比为0.5 g/L,氨氮浓度为70 mg/L,结果表明:以风化花岗岩洗砂尾泥合成的4A沸石对氨氮吸附量为69.1 mg/g,对氨氮去除机理主要为离子交换,符合二级反应动力学,是一种潜在的氨氮高效吸附材料。  相似文献   

4.
王爱民  白妮 《硅酸盐通报》2012,31(5):1117-1121
粉煤灰经过磁选、酸洗预处理,采用碱熔融-水热反应法进行Na-P1沸石的合成研究,探讨了焙烧温度、碱灰比及晶化时间对合成的影响,并将合成产物用于含Cu2+废水处理研究.结果表明:当碱灰比为1.3,焙烧温度为800℃,24 h搅拌陈化,16h晶化后可获得单一的、结晶度较高的Na-P1沸石.合成沸石对含Cu2+废水有较快的吸附能力,投加1 g/100mL含Cu2+ 100 mg/L溶液,常温下25 min,Cu2+去除率可达98%;吸附容量为56 mg/g.  相似文献   

5.
粉煤灰合成沸石及其处理焦化废水A/O出水的试验   总被引:3,自引:0,他引:3  
以NaOH作碱源,采用水热晶化法将粉煤灰转化成沸石.通过改变灼烧温度、NaOH浓度、液固比、晶化时间,考察合成条件对合成沸石阳离子交换容量的影响,并应用于焦化废水A/O出水的处理.结果表明:在灼烧温度为700℃、NaOH浓度为1 mol/L、液固比为5:1 mL/g、晶化时间为36 h条件下,合成沸石的阳离子交换容量最高为167 mmol/100g,是原粉煤灰的12.8倍,高于天然沸石的160 mmol/100 g;合成沸石处理焦化废水A/O出水的最佳条件是反应时间为1 h,沸石投加量为2g/100mL,pH值为6.0~9.0,此时NH3-N、COD去除率及出水质量浓度分别为46.7%、17.6%和62.6、197.8 mg/L,合成沸石对NH广N的吸附符合Freundlich吸附等温式.  相似文献   

6.
夏彬  王晓丽  张艳 《硅酸盐通报》2018,37(4):1462-1466
试验以内蒙古鄂尔多斯煤矸石为原料,采用水热法合成A型沸石吸附剂.以氨氮去除率为指标,通过正交试验考察了焙烧温度、焙烧时间、晶化温度、晶化时间对合成A型沸石的影响并确定了最佳合成条件.结果表明:对A型沸石氨氮去除率的影响顺序为晶化温度>晶化时间>焙烧时间>焙烧温度,最佳合成条件为焙烧温度750℃,焙烧时间2.5 h,晶化温度95 ℃,晶化时间8 h.样品经XRD、SEM、BET表征,得到了形态较佳且结晶度较好的A型沸石,且该产品为良好的吸附剂.  相似文献   

7.
利用壳牌炉粉煤灰水热合成沸石,调节硅铝物质的量比为1.7合成NaA型沸石。通过单因素实验和正交实验优化合成工艺条件,在碱液浓度为1 mol/L、晶化温度为100 ℃、晶化时间为7 h、液固比(mL/g)为5∶1的条件下合成的NaA型粉煤灰沸石的脱氮能力较强,氨氮去除率达74.62%。分析正交实验结果可知,各因素对NaA型沸石脱氮性能的影响程度:碱液浓度>晶化温度>液固比>晶化时间。对较优产品进行分析,可知其结晶度较大、纯度较高;晶体形貌完整、规则;沸石的孔道排列紧密有序。该NaA型沸石可用于处理氨氮废水。  相似文献   

8.
以粉煤灰为原料,在温和条件下水热合成粉煤灰基沸石分子筛,并通过正交试验研究了碱浓度、晶化时间、晶化温度对粉煤灰吸附重金属Cu2+性能的影响,确定在晶化时间10 h、晶化温度80℃、NaOH的质量浓度为8%的工艺条件下合成的分子筛对Cu2+吸附效果最好.经X射线衍射仪分析表明,合成的产物含有NaP1型微孔沸石分子筛.通过比表面积分析仪分析测定样品的比表面积为45.98 m2/g.用优化工艺合成的分子筛去除含铜废水,1500 mg/L的沸石处理该废水30 min,去除率达到93.9%,结果表明,合成的分子筛具有良好的吸附性能.因此,本实验合成工艺简单,条件温和,降低了能源成本和最小化环境影响,有利于工业大规模生产.  相似文献   

9.
混碱改性粉煤灰制备NaP1型沸石   总被引:1,自引:0,他引:1       下载免费PDF全文
本文通过对粉煤灰进行酸处理与不同浓度的NaOH和KOH混碱改性,采用水热晶化法合成了单一的NaP1型沸石.利用X射线衍射(XRD)、扫描电子显微镜(SEM)和X射线荧光光谱仪(XRF)进行测试表征,结果表明:在硅铝比和晶化时间一定的情况下,单一NaP1型沸石的合成主要取决于混碱浓度和晶化温度;在硅铝摩尔比为1.5,晶化时间为8h的条件下,制备单一NaP1型沸石的最佳混碱浓度和晶化温度分别是10 mol/L、120℃.  相似文献   

10.
张子伟  姜晓琳  解强 《硅酸盐通报》2015,34(11):3095-3101
采用分光光度法测定水热合成条件下大同塔山电厂粉煤灰中硅、铝溶出量,据此调配粉煤灰水热合成沸石凝胶体系的硅铝比,在研究优化室温陈化时间、晶化温度和晶化时间等工艺参数的基础上,定向制备出X型沸石;采用氮气吸附仪、X射线衍射仪、醋酸铵法等表征沸石的比表面积、物相组成及阳离子交换容量.结果表明:水热合成条件下大同煤粉煤灰中硅、铝溶出量随时间延长先增大后减小,在14~16 min达到峰值,此时硅、铝溶出率分别为16.9%、9.1%,凝胶体系硅铝比为3.9,适宜制备X型沸石;室温陈化24 h、100℃晶化8h工艺条件下制备的沸石性能较好,比表面积为97.5 m2/g,阳离子交换容量为214.2 cmol/kg,产物主要为NaX型沸石.  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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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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