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1.
改性膨润土对氨氮废水吸附性能的研究   总被引:1,自引:0,他引:1  
用内蒙膨润土及其碱改性膨润土进行模拟氨氮废水的脱氮实验研究。结果表明,在氨氮溶液初始浓度为300 mg/L,pH值为3.0~7.0时,相对于天然膨润土,碱改性膨润土对氨氮的吸附量有了很大提高,其吸附等温线符合Freundlich和Langmuir方程,且对氨氮的吸附动力学符合准一级和准二级吸附动力学模型,说明化学吸附和物理吸附共同起作用;在应用于畜禽废水处理中,碱改性膨润土对氨氮去除率达到91.0%。  相似文献   

2.
以原矿膨润土为原料,对其结构进行表征和分析。然后从单因素条件分析膨润土对Cu2+、Cd2+、Pb2+的吸附效果。结果表明:在相同条件下,膨润土加入量为0.30 g、温度为25℃时,Cu2+初始浓度为200 mg/L,溶液pH值为5.0,其最大吸附率为99.92%;Cd2+初始浓度为150 mg/L,溶液pH值为6.0,其最大吸附率为99.84%;Pb2+初始浓度为50 mg/L,溶液pH值为3.5,其最大吸附率为99.12%。竞争吸附中膨润土对Cd2+吸附效果最佳。此研究对处理含重金属离子的废水具有较好的潜在价值。  相似文献   

3.
制备了一种聚(丙烯酸-CO-丙烯酰胺)/膨润土/腐植酸钠三维网络凝胶吸附剂,重点考察了该吸附剂对Cd2+吸附能力的pH依赖性、吸附动力学和吸附等温线。结果表明,Cd2+溶液的pH值对吸附容量有较大影响。  相似文献   

4.
以钠基膨润土为原料,制备了4种二氧化钛(TiO2)改性柱撑膨润土,并探讨了膨润土的改性方法、投土量、溶液的振荡时间、温度、pH值等因素对膨润土吸附副品红实验的影响.结果表明,4种TiO2改性柱撑膨润土对副品红的吸附效果明显好于原土;未经煅烧的TiO2改性柱撑膨润土的吸附效果要明显优于经高温(500 ℃)煅烧过的柱撑膨润土;掺杂钇的TiO2改性柱撑膨润土的吸附性能略好于未经掺杂的柱撑膨润土;膨润土投土量、溶液的振荡时间、温度和pH值均会对柱撑膨润土的吸附效果产生影响;20 ℃时,4种柱撑膨润土对溶液中副品红的吸附等温线均符合Langmuir吸附等温方程.  相似文献   

5.
《广州化工》2021,49(16)
采用紫外吸收光谱法研究了酸改性膨润土吸附左氧氟沙星的分析方法。实验系统研究了溶液pH值、吸附时间、吸附剂用量等条件对左氧氟沙星测定结果的影响,最终确定了最佳分析条件。结果表明,强酸性条件有利于改性膨润土对左氧氟沙星的吸附,最佳pH值为2,吸附平衡时间为10 min。通过对左氧氟沙星的吸附等温线数据进行拟合,Freundlich等温模型优于Langmuir等温模型。通过描述改性膨润土吸附左氧氟沙星的动力学过程,该吸附过程更符合准二级动力学模型(相关系数为0.99994)。  相似文献   

6.
采用有机酸草酸改性天然膨润土(RB),制备了草酸膨润土(OAB),同时考察了膨润土与草酸质量之比、OAB投加量、溶液初始pH值、亚甲基蓝(MB)初始浓度、吸附时间对OAB去除MB的影响。结果显示,在膨润土与草酸质量比为1:1,OAB投加量为2g/L,溶液初始pH值为6%8,MB初始浓度为200mg/L,吸附2h能达到最佳去处效果,饱和吸附量为96. 9mg/g。进一步研究了OAB吸附MB的吸附动力学和吸附等温模型,结果表明,拟二级动力学和Langmuir模型能更好地描述OAB吸附MB。此外,还采用SEM观察了OAB吸附亚甲基蓝前后的表面微观形貌特征,采用FTIR对吸附前后的OAB进行表征,均表现出了关联性。  相似文献   

7.
改性粉煤灰处理含磷废水的研究   总被引:5,自引:0,他引:5  
采用浓硫酸固相反应法对粉煤灰进行改性用于含磷废水的净化,考察了pH值,吸附剂用量,磷初始浓度,反应时间对净化过程的影响。通过实验发现溶液pH值在4-10范围内对磷的吸附过程影响不显著,改性粉煤灰可以在较宽的pH值范围内进行脱磷处理;随着粉煤灰加入量的增加和初始溶液中磷酸根浓度的降低,磷的净化率逐渐增加。对于含磷50 mg/L的溶液,当粉煤灰的投加量为1.5%时,磷的吸附效率可达99.66%,净化后水中含磷量为0.17 mg/L。改性粉煤灰对水中磷的净化过程速度较快,5 min可达到最大净化率。改性粉煤灰对磷的吸附等温线符合Freudlich方程。  相似文献   

8.
采用从铀钨废水中提取出的一种米根霉菌(OR菌)吸附电镀废水中的镍,探讨了反应时间、溶液pH值、吸附剂用量、溶液Ni2+初始浓度等对OR菌吸附Ni2+效果的影响。实验结果表明,在室温条件下,pH值对吸附效果的影响不明显,吸附剂用量和溶液Ni2+初始浓度对吸附效果的影响显著;在试验的温度范围内吸附等温线符合Langmuir方程。  相似文献   

9.
用层状氢氧化镁铝的焙烧产物吸附水中苯酚,研究了吸附剂用量、吸附时间、温度、溶液pH值等条件对吸附性能的影响。结果表明,吸附主要发生在90min内,吸附量随着温度的升高而增加。溶液初始pH值对吸附影响较大,pH值在6~11范围内吸附效果较酸性时好。吸附符合Langmiur等温线,饱和吸附量为0.557mg/g。  相似文献   

10.
为探讨改性膨润土对Cd(II)的吸附特征及吸附动力学机制,通过吸附实验探讨了pH值、初始浓度和吸附时间对改性膨润土吸附Cd(II)的影响。结果表明,盐酸改性膨润土对Cd(II)的去除率表现为随溶液pH值升高而升高,而氢氧化钠改性膨润土、膨润土与十二烷基磺酸钠改性膨润土的去除率分别在pH=6和7时达到最大值。膨润土及改性膨润土对Cd(II)的去除率随初始浓度的增加而降低,吸附量随平衡浓度增加而增大,并趋向平稳,吸附符合Langmuir方程,吸附为单分子层吸附。膨润土及改性膨润土的吸附反应在240 min内基本达到平衡,吸附动力学分析表明吸附过程更符合准二级动力学模型,吸附过程以化学吸附为主,膨润土及改性膨润土的吸附速率大小依次为K2HCl-B>K2NaOH-B>K2B>K2SDS-B,液膜扩散与颗粒内扩散过程均为控速步骤。该研究可为改性膨润土处理含镉废水和修复镉污染土壤提供参考。  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   

13.
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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15.
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   

19.
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   

20.
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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