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采用沸石填料电化学反应器处理低浓度氨氮废水,研究了阳极材料、粒子电极、阴极材料、电流密度、初始pH、曝气对氨氮去除效果的影响。结果表明,在钌铱锡阳极板(DSA)为阳极、活性碳纤维(ACF)为阴极、载铁斜发沸石为填料、电流密度为6 mA/cm2、pH为5、曝气量为5 L/min条件下,质量浓度为20 mg/L的模拟氨氮废水经处理后出水氨氮质量浓度为3 mg/L左右,且出水水质清澈。NH+4在直流电场作用下向阴极定向移动,曝气对阳极处理氨氮没有影响,·OH氧化氨氮可使氨氮质量浓度降低一半左右,氨氮降低至一定质量浓度时,·OH无法继续对其氧化,阴极附近氨氮质量浓度在20 min后基本保持不变。 相似文献
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《工业用水与废水》2018,(5)
采用天然硅藻土处理低浓度氨氮废水,运用单因素试验法考察了硅藻土投加量、废水pH值和搅拌时间对氨氮去除率的影响,研究结果显示:在其对地表水氨氮(0.277 mg/L)的处理中,当硅藻土投加量为40 mg/L、pH值为7、搅拌时间为25 min时,处理效果最佳,氨氮去除率可达64.5%;在其对咸阳印染废水氨氮(13.4 mg/L)的处理中,当硅藻土投加量为800 mg/L、 pH值为8、搅拌时间为25 min时,处理效果最佳,氨氮去除率可达45.3%;在其对福建印染废水氨氮(26.76 mg/L)的处理中,当硅藻土投加量为2 500 mg/L、 pH值为7、搅拌时间为35 min时,处理效果最佳,氨氮去除率达到51.6%。硅藻土适用于低浓度氨氮废水的处理。 相似文献
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利用硅藻土对氨氮废水的吸附进行实验研究,分别考察了硅藻土投加量、搅拌反应时间、静置时间、pH和沸石投加量对氨氮去除率的影响.试验结果表明,采用硅藻土处理氨氮废水的最佳运行条件为:硅藻土的投加量为0.8 g/L,pH为7.0左右,搅拌反应时间为15 0 min,静置时间为15 0 min,以及沸石的投加量为3.0 g/L... 相似文献
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采用次氯酸钠对城市污水厂二级生物处理出水进行消毒试验,从氨氮浓度、pH、消毒时间、水温这4个方面,分析其对次氯酸钠消毒效果的影响。当氨氮浓度≤0.2 mg/L时,次氯酸钠最佳投加量为15 mg/L;氨氮浓度为0.2~0.4 mg/L时,次氯酸钠最佳投加量为8 mg/L;氨氮浓度约0.6 mg/L时,次氯酸钠最佳投加量为6 mg/L;氨氮浓度为0.8~1.2 mg/L时,次氯酸钠最佳投加量为5 mg/L。当pH值为5. 0~6.0时,10 mg/L的次氯酸钠投加量即可使出水达标,若pH值为8.0~9.0时,必须加大次氯酸钠的投加量至15 mg/L。冬季气温较低时,尾水消毒要考虑延长消毒接触时间。夏季水温较高,可以相应减少加氯量。一般消毒接触时间为15~30 min时消毒效果最佳。 相似文献
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在对NaCl改性沸石吸附处理模拟氨氮水单因素研究基础上,对该吸附过程的吸附等温线及动力学模型进行了分析。实验结果表明:在最佳改性条件下得到的NaCl改性沸石在室温(27℃),初始氨氮浓度30 mg/L,溶液pH值6,投加量5 g/L以及反应时间90 min时,氨氮去除率高达90.7%,吸附剂的吸附容量为8.97 mg/g。且吸附过程更符合Langmuir等温吸附模型,其相关系数为0.9973。吸附动力学分析表明,NaCl改性沸石吸附模拟氨氮水更符合准二级动力学模型,其相关系数为0.9988。 相似文献
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研究以沸石粉为主要原料,添加木屑、淀粉等有机物为碳化结合剂,通过造粒、氮气气氛低温热处理制备得到了粒度为0.5~1 cm的沸石-炭复相材料水处理剂颗粒,研究了不同碳化结合剂含量和不同热处理温度等氨氮超标污水的吸附性能影响。采用场发射扫描电镜对沸石-炭复相材料进行了显微形貌观察。通过氨氮吸附实验得出,相同质量条件下沸石-炭复相材料水处理剂颗粒在吸附速率上弱与沸石粉体,在足够吸附时间下对氨氮的吸附量同沸石粉体吸附量接近。5%碳化结合剂添加量样品有最优氨氮吸附性能,起始浓度为15 mg/L氨氮溶液被吸附24 h后氨氮溶液浓度降为4.69 mg/L,氨氮吸附量为1.03 mg/g;吸附100 h后氨氮溶液浓度降为1.35 mg/L,氨氮吸附量为1.36 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
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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