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1.
以超重力旋转填充床(RPB)为反应装置,研究了O_3/UV工艺处理罗丹明B染料废水的效果。考察了旋转填充床转速、液体流量、催化剂P25质量浓度、臭氧质量浓度等因素对脱色率和COD去除率的影响。结果表明,随着旋转填充床转速、液体循环量、催化剂P25质量浓度以及臭氧质量浓度的增加,罗丹明B废水的处理效果增加;当温度为25℃、液体体积为2 L、RPB转速为1 000 r/min、废水pH为4、气体体积流量为150 L/h、液体循环量为30 L/h、臭氧质量浓度为35 mg/L、催化剂P25质量浓度为400 mg/L时,罗丹明B废水经处理20 min后脱色率和COD去除率分别可达100%和40%。  相似文献   

2.
以Cu(NO3)2•3H2O为原料,采用共沉淀法制备了CuMgLa/Al2O3催化剂,TEM和N2吸脱附结果表明,该催化剂具有介孔结构,主活性组分CuO的粒径约为25 nm。以喹啉为降解目标污染物,考察了温度、催化剂质量浓度等对湿式催化氧化降解喹啉效果的影响。结果表明,当喹啉模拟废水质量浓度为1000 mg/L,催化剂质量浓度为0.2 g/L,反应温度为240 ℃,氧分压为0.53 MPa,反应60 min时,喹啉降解率接近100.0%,化学需氧量(COD)去除率达到94.8%。通过UV-Vis、LC-MS分析喹啉降解生成的中间体,结合叔丁醇淬灭实验,发现·OH氧化在湿式催化氧化降解喹啉体系中起主导作用,推测了喹啉可能的降解路径。在最优工艺条件下,COD质量浓度为7000 mg/L的模拟焦化废水COD的去除率达94.6%;而COD质量浓度为4740 mg/L,NH3-N质量浓度为884.2 mg/L的实际焦化废水COD去除率为69.6%,NH3-N去除率为28.0%。  相似文献   

3.
在旋转填充床(RPB)中超重力环境下采用O3/Fenton法处理含硝基苯废水,考察了Fenton试剂投加次数、超重力因子β、液体流量、初始pH值、Fe2+投加量、H2O2与Fe2+摩尔比对硝基苯去除率的影响. 结果表明,在硝基苯浓度175 mg/L、反应温度25℃、气体流量75 L/h、臭氧浓度40 mg/L、分3次投加Fenton试剂、溶液初始pH值4.5、超重力因子β=80、液体流量140 L/h和Fe2+总投加量1 mmol/L、摩尔比H2O2:Fe2+=5、循环处理40 min的条件下,硝基苯去除率和化学需氧量(COD)去除率分别为99.6%和87.6%. 相近条件下,与RPB-Fenton法相比,硝基苯去除率和COD去除率分别提高了36.3%和4.5%,与RPB-O3法相比分别提高了7.2%和47.1%,与BR(鼓泡反应器)-O3/Fenton法相比分别提高了11.3%和47.8%.  相似文献   

4.
在旋转填料床中进行Fe~(2+)/O_3降解硝基苯废水的实验研究,并考察了初始pH、超重力因子β、液体流量、Fe~(2+)浓度对硝基苯去除率的影响。结果表明,在硝基苯质量浓度为175 mg/L、臭氧质量浓度为40 mg/L、气体流量为75 L/h、pH为3.5、超重力因子β=80、液体流量为140 L/h、Fe~(2+)浓度为0.4 mmol/L、循环处理40 min的条件下,硝基苯去除率和COD去除率分别为99.5%和67.97%。相同实验条件下,与O_3-RPB相比,该工艺的硝基苯去除率和COD去除率分别提高了7.1%和27.51%;与Fe~(2+)/O_3/BR工艺相比,该工艺的硝基苯去除率和COD去除率分别提高了27.2%和32.55%。表明将超重力技术与均相催化臭氧技术相结合,可实现硝基苯的高效降解。  相似文献   

5.
在旋转填料床(RPB)中考察了Mn~(2+)/H_2O_2/O_3处理硝基苯废水的效果。考察了Mn~(2+)浓度、初始p H、超重力因子β、H_2O_2浓度、液体流量对硝基苯去除效果的影响。结果表明,硝基苯去除率随Mn~(2+)浓度、p H、超重力因子β、H_2O_2浓度、液体流量的增加呈先增加后减小的趋势。当硝基苯质量浓度为150 mg/L时,在Mn~(2+)浓度为1.8 mmol/L,p H 2.5,超重力因子β=40,臭氧质量浓度为40 mg/L,H_2O_2浓度为5.0 mmol/L,液体流量为120 L/h,循环处理25 min的条件下,硝基苯去除率和TOC去除率分别可达99.82%、59.24%,硝基苯质量浓度为0.27 mg/L,达国家一级排放标准(GB 8978—1996)。相同实验条件下,硝基苯去除率比RPB-O_3/H_2O_2提高了21.43%,TOC去除率比RPB-O_3/H_2O_2提高了21.08%。  相似文献   

6.
采用硫酸亚铁和过氧化氢所构成的Fenton试剂,对经生化处理后的焦化废水进行Fenton高级氧化深度处理,重点考察了废水初始pH,FeSO4·7H2O、H2O2及PAM投加量对焦化生化废水处理效果的影响。结果表明,采用Fenton高级氧化法可使经生化处理后的焦化废水中的COD、NH3-N和色度得到进一步有效去除。对于中等浓度的焦化生化废水,较适宜的Fenton氧化工艺条件:废水初始pH为8~10,FeSO4·7H2O投加量为500 mg/L,H2O2投加量为3.5 mL/L,PAM投加量为4.0 mg/L。在此条件下,COD、NH3-N和色度的去除率分别可达85.9%、97.3%和84.6%。  相似文献   

7.
采用次氯酸钠(Na Cl O)氧化法对乙炔清净废水进行预处理。分别考察了废水的p H、温度、Na Cl O溶液加入量和反应时间对废水中NH3-N和COD去除率的影响,用正交实验的方法确定了NH3-N的最佳处理条件。结果表明,Na Cl O溶液加入量对NH3-N去除率的影响最大,其次是废水的温度和p H,反应时间的影响最小,对于200 m L的废水,最佳处理条件为:废水的p H为8、温度为50℃、Na Cl O溶液加入量为5.5 m L、反应时间为5 min。此时NH3-N、COD和TN的去除率分别为99.8%、51.9%和90.9%,游离氯的剩余量很低。  相似文献   

8.
US/Fenton氧化-混凝法对焦化废水的预处理研究   总被引:10,自引:0,他引:10  
采用US/Fenton氧化-混凝法对高浓度焦化废水进行预处理.考察了对处理效果的影响因素,确定了最适工艺条件.结果表明,在超声波功率500W,H2O2投加质量浓度为6.0 g/L,Fe2 为400 mg/L,pH 3,Al2(SO4)3、PAM投加量分别为480、4.0 mg/L的条件下,COD、NH3-N、CN-和色度的去除率分别达75.1%、53.4%、62.8%和83.1%,废水的COD由处理前的4 799mg/L降至1 195 mg/L,BOD/COD由0.196提高到0.373,出水可生化性良好.US/Fenton氧化-混凝法可作为高浓度焦化废水的一种有效的预处理方法.  相似文献   

9.
以焦化废水为研究对象,采用水热氧化技术研究废水处理的技术可行性,具有重大的理论和实际应用价值。在连续式反应器中,研究了实际焦化废水中主要污染物指标COD、NH3-N的降解行为。采用水热法处理焦化废水对COD去除率可达90%以上,当温度高于500 K时,COD浓度可降至300 mg/L以下,达到三级排放标准(GB 13456-1992)。停留时间是NH3-N彻底去除的主要因素。在停留时间达到12.46 min、温度为581 K、压力为15 MPa的亚临界条件下,NH3-N浓度可降至2.6 mg/L,达到一级排放标准。  相似文献   

10.
在旋转填充床(RPB)中,研究了O_3/Fenton工艺处理模拟聚丙烯酰胺(PAM)污水的效果。考察了溶液p H值,Fe~(2+)浓度,H2O2浓度,O_3浓度,反应温度与RPB转速对PAM氧化降解率以及化学需氧量(COD)去除率的影响。结果表明,在pH值为4,Fe~(2+)浓度为0.25 mmol/L,H_2O_2浓度为0.8 mmol/L,O_3浓度为50 mg/L,反应温度为25℃,以及RPB转速为800 r/min的条件下,PAM氧化降解率和COD去除率可以达到96.82%与89.96%,表明采用RPB强化O_3/Fenton工艺处理PAM污水具有良好的效果。  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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