共查询到20条相似文献,搜索用时 62 毫秒
1.
采用US/Fe3+/H2O2体系超声催化降解甲基橙,考察了超声波功率、Fe3+初始质量浓度、H2O2用量、甲基橙溶液的初始质量浓度及初始pH值对超声催化降解甲基橙的影响,初步探讨了其降解动力学规律。结果表明,US/Fe3+/H2O2体系能有效降解甲基橙,且超声波与Fenton试剂对甲基橙废水的降解存在强烈的协同作用;在pH=3、超声波功率500 W、Fe3+和H2O2的初始质量浓度分别为30 mg/L和150 mg/L时,对含30 mg/L的甲基橙溶液降解120 min,其去除率达到99.5%;甲基橙的超声催化降解符合一级反应动力学规律,且甲基橙的一级反应速率常数随其初始质量浓度增大而降低。 相似文献
2.
采用UV/Fe3+/H2O2催化-混凝联合工艺对难处理络合铜镍电镀废水进行了研究,考察了Fe3+和H2O2初始浓度、初始pH值、温度、反应时间及混凝液pH、混凝剂质量浓度对处理过程的影响,探讨了废水的降解途径和机理.结果表明在体系初始pH=3,温度50℃,H2O2和Fe3+初始浓度分别为1.5×10-4mo1/L、2.5×10-5mo1/L,反应时间60min,混凝液pH=8及混凝剂质量浓度为500mg/L的条件下,废水的COD去除率为96.98%,Cu2+为99.91%,Ni2+为99.92%,处理水达到国家一级排放要求.同时依据GC/MS对X-GN降解最终产物的分析结果,推导出废水的基本降解机理和途径. 相似文献
3.
研究了芬顿(Fe2+/H2O2)体系和亚铁离子活化过硫酸钠(Fe2+/PS)体系在降解地下水氯苯(CB)过程中对氯苯酚(p-CBOH)稳定中间体的产量,运用响应面法考察了氧化剂(H2O2或Na2S2O8)投加量、催化剂(Fe2+)投加量以及初始pH对CB降解率和p-CBOH产量的影响.结果表明,当pH为2.40,H2O2投加量为1.31 mmol/L,FeSO4投加量为1.41 mmol/L时,Fe2+/H2O2体系降解CB过程中产生p-CBOH中间体的最小质量浓度为0.30 mg/L,与预测值0.36 mg/L较吻合;当pH为4.00,Na2S2O8投加量为3.50 mmol/L,FeSO4投加量为1.50 mmol/L时,Fe2+/PS体系降解CB过程中产生p-CBOH中间体的最小质量浓度为0.00 mg/L,与预测值完全吻合.上述两种情况下CB的去除率均为100%. 相似文献
4.
以偶氮染料橙黄G(OG)为目标污染物,研究Fe2+分别催化H2O2、S2O82-、H2O2-S2O82-降解0.1 mmol/L OG Fe2+/H2O2体系,[Fe2+]=1 mmol/L, pH=3, [H2O2]0=10 mmol/L,降解30 min OG脱色率为96%,随着pH值增大和[H2O2]0>10 mmol/L,OG脱色率减小,呈线性变化。Fe2+/S2O82-体系,随着S2O82-初始浓度增加OG脱色率增大,随着pH值增大OG脱色率减小,呈非线性变化。Fe2+/H2O2-S2O82-体系,pH=3, [H2O2]0=2 mmol/L, [S2O82-]0>10 mmol/L时OG脱色率持续增大。Fe2+/H2O2-S2O82-体系矿化率最高。利用乙醇和硝基苯作为分子探针,采用分子探针竞争实验鉴定该体系中产生的SO4?和OH?。 相似文献
5.
采用由小麦秸秆制备的生物炭(Biochar,BC)作为纳米零价铁(Nanoscale zero-valent iron,n ZVI)载体,制备出一种高效非均相催化剂-生物炭负载纳米零价铁(n ZVI@BC),用于活化过一硫酸盐(Peroxymonosulfate,PMS)降解高硫酸盐印染废水中的典型染料亚甲基蓝(Methylene Blue,MB)。n ZVI@BC 表征结果表明,BC 具有优良的稳定性且富含活性官能团,负载于 BC 上的 n ZVI 分散性好。通过批次实验探究了初始 p H、n ZVI@BC 投加量、PMS 浓度和硫酸钠浓度对 n ZVI@BC/PMS 体系降解 MB 的影响。结果表明,在 MB 初始质量浓度为 40 mg/L,p H 为 3,n ZVI@BC 投加量为 0.2 g/L,PMS 质量浓度为 0.4 g/L,Na2SO4浓度为 0.2 mol/L 的条件下,反应 30 min 后 n ZVI@BC/PMS 体系对 MB 的降解率达到 90.36%。Na2SO4浓度超过... 相似文献
6.
以偶氮染料酸性大红为研究对象,通过正交实验确定了Fe3+/H2O2类Fenton体系中,Fe3+浓度,H2O2浓度及反应溶液pH等因素的影响。同时考察了反应时间、H2O2浓度、Fe3+浓度和pH对脱色效率的影响。实验表明对于50 mg/L的酸性红染料,Fe3+/H2O2体系脱色反应基本能在60 min内完成。pH=3,[H2O2]=33 mg/L,Fe3+浓度为25 mg/L时,染料脱色率达到97.2%。增加双氧水的投加量能够明显促进染料的降解脱色。Fe3+浓度大于25 mg/L,Fe3+投加量的增加不会明显促进染料的脱色,体系pH是最重要的影响因素。在酸性条件下,Fe3+催化效果优于Fe2+,拓展了Fenton反应的应用。 相似文献
7.
以五水硝酸铜和碘化钾为原料,采用以乙二醇为溶剂的溶剂热法,通过水热温度的控制对BiOI进行形貌调控,制备了3D球状碘氧化铋(BiOI)光催化剂。应用SEM、EDS、XRD、UV-Vis对材料结构进行了表征,将BiOI与过一硫酸盐(PMS)耦合于可见光下降解偶氮染料金橙Ⅱ,探究了BiOI投加量、PMS投加量、金橙Ⅱ浓度、pH及常见阴离子对降解体系的影响。结果显示,BiOI拥有良好的可见光响应性能,禁带宽度为1.8eV,在BiOI投加量为0.2g/L,PMS浓度为0.2mmol/L,金橙Ⅱ质量浓度为100mg/L时降解效率最好,高达97.0%,降解过程符合准二级动力学模型。降解过程中可见光激发BiOI产生光生载流子,一方面光生载流子与PMS反应,生成硫酸根自由基和羟基自由基(·SO4-,·OH),另一方面光生载流子与体系中的溶解氧反应生成超氧自由基(·O2-),·O2-与H2O中H+反应生成单线态氧(1O2),同时PMS自分解产生1O2,说明降解过程是多途径的非均相反应,·O2-、1O2是降解过程中的主要自由基。 相似文献
8.
以偶氮染料橙黄G(OG)为目标污染物,研究Fe2+分别催化H2O2、S2O82-、H2O2-S2O82-降解0.1 mmol/LOG Fe2+/H2O2体系,[Fe2+]=1 mmol/L,pH=3,[H2O2]0=10 mmol/L,降解30 min OG脱色率为96%,随着pH值增大和[H2O2]0>10 mmol/L,OG脱色率减小,呈线性变化。Fe2+/S2O82-体系,随着S2O82-初始浓度增加OG脱色率增大,随着pH值增大OG脱色率减小,呈非线性变化。Fe2+/H2O2-S2O82-体系,pH=3,[H2O2]0=2 mmol/L,[S2O82-]0>10 mmol/L时OG脱色率持续增大。Fe2+/H2O2-S2O82-体系矿化率最高。利用乙醇和硝基苯作为分子探针,采用分子探针竞争实验鉴定该体系中产生的SO4.和OH.。 相似文献
9.
利用水热法将MnFe2O4负载在生物质气化炭渣(CR)得到负载型复合催化剂MnFe2O4-CR,通过SEM、XRD、XPS、BET和VSM等技术对复合催化剂进行表征,并将其用于活化过一硫酸盐(PMS)降解盐酸四环素(TC)。考察了不同反应体系、催化剂的不同复合比例、PMS用量、催化剂用量、温度、pH、阴离子(HCO3–、H2PO4–、Cl–、NO3–)和腐植酸(HA)对MnFe2O4-CR/PMS体系降解TC的影响,并探究了MnFe2O4-CR的稳定性和循环使用性,探讨了MnFe2O4-CR/PMS体系中TC可能的降解机理。结果表明,MnFe2O4与炭渣的质量比为1∶2时制备的MnFe2O4-CR催化效果良好,在30 ℃,30 mg MnFe2O4-CR催化40 mg PMS,在90 min内对100 mL质量浓度为50 mg/L自然pH的TC溶液中TC的降解率达到91.32%;MnFe2O4-CR可利用其磁性回收,经过5次循环利用,催化PMS降解TC的降解率仍能达到82.90%。表明MnFe2O4-CR具有良好的稳定性和重复使用性。自由基淬灭实验表明,MnFe2O4-CR/PMS体系中,SO4??、?OH 、1O2 和O2??是降解TC的主要活性氧物种,并提出了相应的催化降解机理。 相似文献
10.
曝气循环Fe~(3+)/UV光催化降解酸性橙Ⅱ 总被引:1,自引:0,他引:1
研究了曝气作用下Fe3+的UV光催化体系(Fe3+/UV/O2)对染料酸性橙Ⅱ的降解效果。试验结果表明,在该体系中染料的降解主要通过Fe3+光解反应产生.OH来完成。此外,曝气导致了Fe2+的光氧化并实现了降解反应的持续进行。在紫外灯功率为15 W、Fe3+的投加量为10 mg/L的条件下,经过180 min的反应,初始质量浓度为100 mg/L的酸性橙Ⅱ溶液能够完全降解。进一步的动力学分析表明酸性橙Ⅱ的降解符合一级反应动力学模型。 相似文献
11.
12.
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
13.
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
14.
15.
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
16.
17.
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.
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
20.
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