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1.
实验考察不同温度下活性炭纤维(ACFs)对苯酚的静态吸附性能,利用Langmuir、Redlich-Peterson吸附等温模型和准二级动力学模型计算苯酚在ACFs上的动力学和热力学性能。结果表明:Redlich-Peterson吸附等温模型和准二级动力学模型能较好地描述吸附性能;升高温度,ACFs的最大吸附容量Q max减小,动力学吸附速率常数K2变大,吸附过程的吉布斯自由能ΔG的绝对值减小,吸附过程的焓变ΔH、熵变ΔS和吸附活化能E a分别为-10.2 kJ/mol、-23.6 J/(mol·K)和55.2 kJ/mol,吸附过程为物理吸附。  相似文献   

2.
采用浸渍法以氧氯化锆修饰颗粒活性炭,获得Zr-GAC.用扫描电子显微镜、X射线衍射仪和比表面仪对等方法对修饰活性炭性能进行表征,结果表明:氧氯化锆负载在活性炭上为ZrO_2.以苯酚为去除目标,研究了Zr-GAC在电化学氧化处理4-氯酚模拟废水过程,实验结果表明:ZrGAC三维电极对4-氯酚具有降解作用,粒子电极投加量10 g,电解质硫酸钠浓度2 g/L、板间距4 cm,电流强度1 A,电解500 mg/L4-氯酚模拟废水300 ml,电解180 min时,4-氯酚去除率可达98.5%,降解过程中产生4-氯邻苯二酚、苯酚、对苯二酚、苯醌、反丁烯二酸、草酸.  相似文献   

3.
粒状活性炭对水中双酚A吸附性能的研究   总被引:1,自引:0,他引:1  
研究了粒状活性炭(GAC)对水环境中内分泌干扰物双酚A(BPA)的吸附动力学和热力学特性,分别讨论了温度、溶液pH以及背景离子的存在等因素对整个吸附过程的影响。研究结果表明:在吸附开始阶段,不同质量的活性炭吸附速率均较大,约3 h达到吸附平衡。吸附量随着温度的升高而减小;当pH≥10时,吸附量随着双酚A的电离而减小;背景离子的存在使得吸附量下降。活性炭对双酚A的吸附过程遵循二级动力学方程。用Langmuir方程可以比较好的对吸附等温线进行拟合;对吸附热力学研究表明:ΔH0,说明吸附为放热过程;ΔG0,说明双酚A倾向于从溶液中吸附到活性炭表面,反应过程是自发进行的;ΔS0,说明吸附过程对溶液体系属于熵减小的过程,活性炭对双酚A的吸附比解吸强烈。  相似文献   

4.
污泥活性炭对活性艳红K-2BP染料的吸附特性研究   总被引:6,自引:0,他引:6  
以城市污水处理厂脱水污泥作为原料,采用化学活化法(ZnCl2作为活化剂)制得污泥活性炭,并将其用于吸附活性艳红K-2BP染料.考察了吸附剂投加量、吸附时间和pH值对吸附效果的影响,并对其吸附动力学和热力学特性进行了探讨. 结果表明,所制得的污泥活性炭的碘吸附值为326mg.g-1,产率为51.31%,BET比表面积为298m2.g-1,具有中孔性和开放的孔结构,浸出液重金属含量不超标;污泥活性炭对活性艳红K-2BP的吸附动力学符合二阶段吸附速率方程和伪二级动力学方程;此吸附为优惠吸附,Langmuir等温方程比Freundlich等温方程更适合于描述此吸附行为;此吸附是一个吸热过程(吸附焓ΔH>0),提高温度有利于吸附的进行,吸附自发进行(吸附自由能ΔG<0),吸附熵ΔS总是正值.  相似文献   

5.
为考察温度对生物吸附性能的影响,采用传统的静态试验方法,以4-氯酚为吸附质,厌氧颗粒污泥为吸附剂,研究了温度对4-氯酚在厌氧颗粒污泥上吸附性能的影响。实验结果表明,不同温度下4-氯酚在厌氧颗粒污泥上的吸附可以很好地用Langmuir吸附等温方程(L方程)和Freundlich吸附等温方程(F方程)进行描述。L方程和F方程的相关系数R2分别在0.92~0.99和0.82~0.97之间,25℃时达到最高,分别为0.97(L方程)和0.99(F方程)。结果还表明,温度是影响4-氯酚在厌氧颗粒污泥上吸附的重要因素,随着温度的增高,平衡吸附量降低,4-氯酚在厌氧颗粒污泥上的吸附过程为放热过程。  相似文献   

6.
为考察温度对生物吸附性能的影响,采用传统的静态试验方法,以4-氯酚为吸附质,厌氧颗粒污泥为吸附剂,研究了温度对4-氯酚在厌氧颗粒污泥上吸附性能的影响。实验结果表明:不同温度下4-氯酚在厌氧颗粒污泥上的吸附可以很好地用Langmuir吸附等温方程(L方程)和Freundlich吸附等温方程(F方程)进行描述。L方程和F方程的相关系数R2分别在0.92~0.99和0.82~0.97之间,25℃时达到最高,分别为0.97(L方程)和0.99(F方程)。结果还表明,温度是影响4-氯酚在厌氧颗粒污泥上吸附的重要因素,随着温度的增高,平衡吸附量降低,4-氯酚在厌氧颗粒污泥上的吸附过程为放热过程。  相似文献   

7.
通过模拟植物根际酸性环境制得硅钾矿肥不溶残余物,研究了水溶液的pH值对Cu2 的吸附性能的影响和吸附机理。结果表明,不溶残余物对Cu2 的吸附符合Freundlich吸附等温式,吸附符合二级吸附动力学,其吸附过程由孔隙的内扩散控制,求出了有效扩散系数;温度升高,吸附平衡量增大,其吸附过程是吸热过程,求出反应的焓变ΔH和熵变ΔS、各温度下的吉布斯自由能变化ΔG。  相似文献   

8.
以表面聚合法制备纳米Fe_3O_4表面聚合磁微粒,研究纳米Fe_3O_4表面聚合磁微粒对芴和荧蒽的吸附热力学和动力学特性.结果表明,纳米Fe_3O_4表面聚合磁微粒对芴和荧蒽等温吸附过程符合准二级动力学方程.在5 22 mg/L浓度范围内,纳米Fe_3O_4表面聚合磁微粒对芴和荧蒽的吸附行为符合Langmuir等温方程,30 60℃温度范围内,吸附自由能ΔG0,吸附焓变ΔH0,吸附熵变ΔS0,表明吸附是一个自发的、吸热的熵增过程.  相似文献   

9.
采集不同土质土壤,以恒温振荡模拟土壤对4-氯酚的流动吸附,分光光度法测定,研究了4-氯酚在花土、草坪土、湖边泥土等不同种类土壤和同类不同成分配比土壤中的吸附行为。结果表明:4-氯酚与土壤溶液接触振荡前2~3h进行吸附阶段,很快吸附到土壤颗粒表面,吸附量迅速增加,溶液中4-氯酚浓度降低,吸附平衡时间约为3~6h。随着反应的进行,土壤中较易吸附的疏水位点逐渐被4-氯酚占据,4-氯酚开始向土壤内部不易吸附的疏水位点,吸附速度开始减缓,溶液中4-氯酚浓度变化不大。3种土壤中草坪土对4-氯酚的吸附能力最强;对于含不同配比腐殖酸的花土,随着腐殖酸的含量增加,土壤对4-氯酚的吸附能力也逐渐增强。4-氯酚在混土2中的吸附系数Kd为0.036mL/g,有机碳吸附常数KOC为4.235mL/g,具有很强的移动性;4-氯酚在花土中的吸附系数Kd为0.017 3mL/g,有机碳吸附常数KOC为2.477mL/g,具有很强的移动性;4-氯酚在泥土中的吸附系数Kd为1.55mL/g,有机碳吸附常数KOC为310.02mL/g,具有中等的移动性。  相似文献   

10.
本文通过静态吸附实验,研究了NKA大孔吸附树脂吸附甘草酸三铵盐过程的吸附动力学和吸附热力学特征,以期为甘草酸大孔吸附树脂分离提纯提供理论支持。实验采用紫外可见分光光度法测定了吸附动力学曲线和不同温度时的吸附等温线,用拟二级动力学方程很好地描述了吸附动力学过程,使用Langmuir方程较好地拟合了等温吸附热力学过程。实验结果显示:NKA大孔吸附树脂对甘草酸三铵盐吸附焓变ΔH吸附和熵变ΔS吸附为正值,自由能变ΔG为负值,吸附活化能为Ea=36.01kJ/mol;该吸附过程是自发的吸热过程,属于物理吸附范畴。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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