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1.
将椰子壳在高温缺氧条件下热解制备了椰壳生物碳(CSBC),考察了Cd(II)溶液pH、初始浓度、吸附时间对CSBC吸附Cd(II)性能的影响,通过FTIR、XRD、XPS、EDS等方法对CSBC以及CSBC-Cd(II)进行了表征,研究了CSBC对Cd(II)的吸附机理。结果显示:pH对CSBC吸附Cd(II)有显著的影响,pH 5为最佳吸附条件;CSBC吸附Cd(II)的过程符合Pseudo-second-order model模型和Langmuir模型,吸附过程以化学吸附为主,拟合的饱和吸附量为29.36 mg/g。研究显示活性官能团与Cd(II)形成配合物,以及Cd(II)与CSBC表面的CO32-生成CdCO3和Cd(OH)2沉淀是主要的吸附机理。  相似文献   

2.
利用模板法合成介孔纳米γ-Al2O3,用透射电镜(TEM)、X射线衍射(XRD)、比表面测定(BET)等手段对所得的介孔纳米γ-Al2O3进行了表征.考察了介孔纳米γ-Al2O3在静态条件下对硫酸根离子的吸附性能.探讨了溶液的初始浓度、pH值、时间和温度对吸附性能的影响,结果表明:介孔纳米γ-Al2O3对硫酸根离子有较好的吸附性能,其吸附行为符合Freundlich等温式.  相似文献   

3.
利用模板法合成介孔纳米γ=Al2O3,,用透射电镜(TEM)、X射线衍射(XRD)、比表面测定(BET)等手段对所得的介孔纳米γ-Al2O3进行了表征.考察了介孔纳米γ-Al2O3在静态条件下对硫酸根离子的吸附性能.探讨了溶液的初始浓度、pH值、时间和温度对吸附性能的影响,结果表明:介孔纳米γ-Al2O3对硫酸根离子有较好的吸附性能,其吸附行为符合Freundlich等温式.  相似文献   

4.
用天然存在且吸附能力较强的果胶包覆具有磁性的四氧化三铁纳米颗粒制备一种吸附剂-Fe3O4果胶磁性微球.通过红外光谱、扫描电镜对样品进行表征,并考察吸附时间、Cu2+的质量浓度、吸附剂用量和吸附溶液的pH值对果胶磁性微球吸附溶液中Cu2+量的影响.结果表明,果胶磁性微球对铜离子的吸附主要发生在最初的1.5 h内,通过1.5 h的吸附后,吸附反应慢慢达到平衡,果胶磁性微球的平衡吸附量为72.50 mg/g.  相似文献   

5.
以氯甲基化交联聚苯乙烯(CMCPS)微球为起始原料,与对羟基苯甲醛(HBA)发生反应,制得醛基化改性聚苯乙烯微球(ALCPS),然后再将ALCPS与氨基葡萄糖盐酸盐发生缩合反应,制得席夫碱型螯合树脂AGCPS微球.探究了该树脂对铅离子的吸附性能,测试不同的pH、吸附时间、吸附温度、铅离子溶液的浓度对吸附性能的影响.结果表明:EDTA螯合树脂对镉离子的吸附量随pH值的增大而降低;随吸附时间的延长而增强,然后趋于平缓;随温度升高而增大;随初始离子溶液浓度的增大而不断增强.且其吸附过程符合Langmuir等温吸附方程和Lagergren一级动力学方程.  相似文献   

6.
以人工合成的纳米碳羟基磷灰石(n-CHAP)吸附水溶液中的镉离子(Cd2+),考查pH值、反应时间及Cd2+初始浓度等因素对吸附效果的影响,并探讨吸附机理。结果表明:n-CHAP对Cd2+的吸附过程符合拟二级反应动力学方程;吸附类型符合Langmuir等温吸附模型,最大吸附量为86.17 mg/g。  相似文献   

7.
竹炭对水溶液中Cd(Ⅱ)的吸附研究   总被引:5,自引:1,他引:4  
研究了竹炭对溶液中Cd (Ⅱ) 的吸附行为.考察了酸处理、pH值、竹碳与溶液的接触时间、投料量、吸附温度和Cd (Ⅱ)的初始浓度对吸附的影响.结果表明竹炭对镉离子的吸附是放热过程,并且符合Freundlich吸附模型,在初始浓度为15 mg·L-1、最佳酸度及287K条件下,未经处理的竹炭饱和吸附量达到11.0 mg·g-1,增加竹碳的用量,镉离子吸附率可达99%以上.  相似文献   

8.
探讨了吸附时间、溶液pH、重金属离子初始质量浓度、离子强度以及竞争吸附等因素对天然高岭土吸附水中Pb2+,Cd2+,Ni2+,Cu2+等重金属离子的影响.结果表明,pH、初始质量浓度、离子强度以及共存离子,是影响高岭土吸附重金属离子的主要因素;高岭土对Pb2+的吸附性能明显优于其它3种重金属离子,顺序为:Pb2+>Cd2+>Ni2+>Cu2+;吸附等温线均符合Freundlich型等温方程,说明高岭土对这几种离子都是典型的单分子层吸附;Pb2+,Cd2+,Ni2+,Cu2+离子解吸量大小顺序为:Pb2+<Ni2+<Cu2+<Cd2+.  相似文献   

9.
采用滴定-固化包裹法制备得到以海藻酸钙(Alg)为壳,内包聚苯乙烯磺酸钠溶液(PSSA)的椭球状软胶囊 (PSSA@Alg软胶囊),用其吸附溶液中的Cu(II)和Cd(II).结果表明: PSSA@ Alg 软胶囊对溶液中Cu(II)和Cd(II) 的吸附量随溶液 pH 升高而增大,吸附过程包括表面吸附和固态海藻酸钙壳内缓慢扩散, 符合拟二级动力学模型, 分别在约240,360 min时达到吸附平衡;等温吸附数据与Langmuir模型拟合良好,25 ℃ 条件下,PSSA@Alg软胶囊 对Cu(II)和Cd(II)的最大吸附量分别为143.92,193.64 mg·g-1. 海藻酸钙上的羧基和聚苯乙烯磺酸钠上的磺酸基 团在重金属离子吸附过程中起重要作用.  相似文献   

10.
以三乙醇胺为催化剂,十六烷基三甲基溴化铵(CTAB)为模板剂,通过硅烷四乙酯(TEOS)和3-巯丙基三乙氧基硅烷(MPTES)共水解,成功制备了巯基功能化介孔二氧化硅纳米微球.用盐酸-乙醇混合溶液去除模板后,这种介孔纳米微球能有效吸附银离子,进一步反应得到SiO2-Ag和SiO2-Ag2S复合纳米微球.用X射线衍射、透射电子显微镜、热分析以及紫外-可见光谱表征了微球形貌、结构与性能.这种复合纳米微球平均粒径约70nm,Ag2S微粒小于10nm且担载于SiO2微球表面,而Ag量子点则包覆于介孔硅的内部,在350nm到700nm范围呈现明显的宽吸收.另外,这两种复合纳米微球作为无机抗菌剂都表现出良好的抗菌性能.  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.
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   

13.
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   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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