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1.
为了去除水中残留的低浓度苯酚,采用水蒸气活化法制备废轮胎活性炭,分析了废轮胎活性炭自水溶液吸附低浓度苯酚的吸附动力学特性,考察了吸附剂投加量和苯酚初始浓度对吸附过程的影响。分别采用拟一级反应、拟二级反应和颗粒内扩散反应模型对不同温度下的反应动力学数据进行拟合。研究结果表明:拟二级反应动力学模型能够较好地描述废轮胎活性炭吸附低浓度苯酚的动力学数据,颗粒内扩散影响吸附速率,但不是唯一的速率控制步骤,计算得到的表观吸附活化能表明,该吸附过程以物理吸附为主,废轮胎活性炭用量为0.3 g/L时,苯酚浓度小于2 μg/L。  相似文献   

2.
以生物质废弃物柚子皮为原料对工业废水中的镉离子进行吸附.考察金属离子初始浓度、吸附剂用量、溶液pH、吸附温度和吸附时间对镉离子的吸附情况,从而确定最佳的吸附条件,并对吸附性能进行动力学研究.结果表明,吸附温度为25 ℃、溶液pH=5、吸附剂的用量为7 g·L -1 、吸附时间为120 min、镉离子的初始浓度100 mg·L -1 条件下,柚子皮对镉离子的吸附率达到96.45%以上;通过用准一级动力学模型和准二级动力学模型进行数据拟合,结果显示吸附反应符合准二级动力学方程;红外光谱结果显示,参与吸附反应的主要官能团为羟基、羰基和羧基.  相似文献   

3.
选取由无烟煤和桃核制备的商用活性炭,考察了25~45℃,初始浓度60~200 mg/L下,它们对水溶液中孔雀石绿的吸附时间和平衡吸附量.通过准一级动力学模型、准二级动力学模型和粒子内扩散动力学模型,分析了吸附动力学;通过Langmuir模型和Freundlich模型对吸附平衡进行了研究.结果表明,虽然煤质炭和桃核炭对孔雀石绿的吸附行为不同,但是准二级动力学模型和Langmuir模型均可以拟合实验数据,这说明它们对孔雀石绿的吸附机理是相同的.通过关联孔结构参数,发现活性炭的比表面积是影响吸附性能的关键因素.  相似文献   

4.
采用微波高温烧结炉分别在600℃,700℃和800℃下对商业活性炭进行改性,利用比表面积及孔径分析仪、Boehm滴定、傅立叶变换红外光谱比较分析活性炭的比表面积和孔结构、表面官能团等物化性质.以1,2-二氯乙烷为吸附质进行固定床吸附实验.研究表明:改性后活性炭表面酸性基团减少,碱性基团随温度升高增多;比表面积、孔容减小,微孔比表面积增加;活性炭对1,2-二氯乙烷的吸附量排序为:AC-800AC-700AC-600AC-0;灰色关联度分析结果表明:改性活性炭的物理结构特性对吸附量的影响大于表面基团;D-R模型和动力学模型拟合结果都表明活性炭对1,2-二氯乙烷的吸附主要为物理吸附.  相似文献   

5.
采用氯化锌-软锰矿活化法制备核桃壳活性炭并研究其对废水中苯酚的吸附特性,结果表明:软锰矿的投加量占原料的5%、氯化锌浓度为3 mol/L、剂料比为1、活化温度600℃、活化时间10min是活性炭的最佳制备条件。在此条件下亚甲基蓝脱色力是123mL/g,碘吸附值945mg/g。在18℃、pH=2条件下,0.5g核桃壳活性炭对50mL的50mg/L苯酚溶液吸附240min吸附效果最佳,吸附效果优于市煤质活性炭。  相似文献   

6.
针对低温微污染水中(7℃)低质量浓度As(Ⅲ)/As(Ⅴ)离子(0.5 mg/L),通过优化配煤、改进制备工艺制备,制备一种中孔型活性炭(NCPAC),以普通商品活性炭PVAC为对照,研究了NCPAC的表面物理化学特性,并进行了pH影响和吸附等温线、吸附动力学方程及吸附热力学拟合研究.结果表明,NCPAC的孔径分布、总孔容积和表面极性大小等方面均得到改善.在酸性/偏中性范围内(pH=4.0~8.0),NCPAC对As(Ⅲ)、As(Ⅴ)均有较好的去除效果,除砷效果明显高于普通商品活性炭.NCPAC对As(Ⅲ)/As(Ⅴ)的吸附平衡可用Langmuir进行较好的拟合;动力学研究表明NCPAC对As(Ⅲ)/As(Ⅴ)的吸附过程可用假二级动力方程进行很好的拟合(R20.999),且As(Ⅲ)/As(Ⅴ)在活性炭表面的吸附过程以化学吸附为主;热力学数据显示,NCPAC对As(Ⅲ)、As(Ⅴ)的吸附过程均为放热反应.共存离子方面,天然水体中常见的磷酸氢根、硅酸根、碳酸根对NCPAC除砷效果有一定的抑制作用,铝离子会降低其对As(Ⅲ)的吸附效果,其他阴阳离子对除砷效果影响不大.  相似文献   

7.
含铜氧化铝对煤油中硫醇的吸附特性   总被引:2,自引:0,他引:2  
利用油乳法制备了含铜氧化铝吸附剂.经筛选,获得一种含铜氧化铝,当煤油中硫醇起始浓度为456.9mg/L时,它对煤油中硫醇的吸附容量达到226mg/g.含铜氧化铝对煤油中硫醇的吸附动力学遵循准二级反应动力学模型,也可用Lagergren一级吸附速率方程描述.二级反应速率常数k2的数值范围为3.86×10-5~43.64×10-5g·mg-1·min-1,并随硫醇起始浓度的增加而减少.一级吸附速率常数k1的数值为6.00×10-3~14.28×10-3min-1,并随硫醇起始浓度增加而增加.由二级速率方程计算出的吸附平衡吸附量qec与实验确定的平衡吸附量qee之间的误差在7%以内.吸附等温线既遵从Langmuir方程,也可用Freundlich方程拟合.由Langmuir方程计算的单层最大吸附量q0为222.2mg/g.  相似文献   

8.
载铁颗粒活性炭(IOCGAC)去除废水中Cr(VI)的研究   总被引:1,自引:0,他引:1  
采用溶液浸溃一加热法制备栽铁颗粒活性炭(10CGAC).并通过SEM/EDAX进行表征,研究了不同实验条件(pH值、初始浓度、吸附剂投加量和共存无机离子)下吸附除Cr(Ⅵ)的效果.结果表明:随着pH值的升高,吸附去除率降低;相同实验条件下,10CCAC的吸附效果明显优于颗粒活性炭(GAC);SO12-对吸附具有抑制作用.吸附动力学实验数据符合准二级反应动力学模型,温度升高,反应速度常数以及吸附容量也随之增加.  相似文献   

9.
K_2CO_3-HNO_3法制备活性炭及其对苯酚吸附动力学研究   总被引:1,自引:0,他引:1  
活性炭因其发达的孔结构而常用于水中有机物的吸附脱除.利用农作废弃物玉米秸秆为原料,K2CO3-HNO3为活化剂制备低成本、高比表面积的活性炭,并研究该活性炭对水中苯酚的吸附特性,通过测定时间和溶液温度对吸附的影响,探讨了吸附过程的动力学及吸附机制;采用扫描电镜观测活性炭表面形貌,采用低温液氮吸附测定数据,以BET方程对活性炭孔结构进行计算表征.结果表明,该活性炭表面孔状结构明显,其比表面积和孔容积发达,分别达到1 652.7 m2/g和1.28 cm3/g,明显优于K2CO3法活性炭和商业活性炭;K2CO3-HNO3法活性炭对苯酚的吸附在50 min左右基本达到平衡,但温度升高对其不利,说明该吸附过程属于放热反应;吸附符合准二级动力学方程,说明整个过程包含扩散、吸附多方面;Freundlich模型与实验数据有较好的线性相关性,说明苯酚属于多分子层吸附.  相似文献   

10.
运用磷酸浸渍硼酸催化法制备木屑活性炭,并进行了其对水中酸性红的平衡吸附实验.研究结果表明木屑活性炭制备的最佳工艺条件为:磷屑比为1:1,硼酸投加量为3%,活化温度为400℃,该条件下所制备的生物活性炭对酸性红的理论最大吸附量可达到442.40mg/g.相对于Freundlich方程,该活性炭对酸性红的吸附等温线与Langmuir方程拟合的更好.当吸附时间达到2h时活性炭吸附达到平衡,吸附过程能较好的拟合准二级动力学方程,吸附以化学吸附为主.  相似文献   

11.
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   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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   

14.
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   

15.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

16.
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   

17.
18.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

19.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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