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1.
萃取-反萃取以提取酸溶液中的镓   总被引:2,自引:1,他引:1  
以磷酸三丁酯为萃取剂,NH4Cl为反萃剂,系统探究了不同萃取环境下萃取和反萃取效果,实验结果表明,在6 mol/L的盐酸体系中,将体积分数为30%的TBP,按1∶1的相比,震荡6 min以萃取25 mg/L的镓溶液,萃取率达98.61%~98.69%,硫酸-氯化钠体系也可实现良好的萃取效果,此外还考虑了其他离子的干扰作用。而在pH=5.5,反萃取剂浓度为2.5 mol/L,反相比为2∶1的条件下,反萃取率可达100%,优化了萃取-反萃取条件,实现了镓的高效回收。  相似文献   

2.
离子交换—丁基罗丹明B光度法测定铅锌矿中微量镓   总被引:1,自引:0,他引:1  
本文研究了用国产强碱性氯型阴离子交换树脂分离除去矿石中大量存在的Zn^2 ,Pb^2 ,Al^3 ,Ca^2 等离子对镓测定的干扰,用6mol/L的HC1-抗坏血酸溶液消除Fe^3 等高价杂质离子的影响,留于柱上的镓用0.5mol/L HCl溶液洗脱,在酸性和TiCl3存在条件下,用苯萃取,测定GaCl4^-与丁基罗丹明B形成的紫红色配合物。用于铅锌矿石中微量镓(Ca)的测定,回收率在96.3%左右,RSD为24‰,结果令人满意。  相似文献   

3.
真菌吸附重金属离子的研究   总被引:4,自引:0,他引:4  
利用黑曲霉和简青霉制备生物吸附剂,研究了它们对重金属Pb2 离子和Cd2 离子的吸附、解吸行为以及实验条件对吸附的影响,包括吸附剂用量、溶液pH值、吸附时间以及共存离子等因素.结果表明,黑曲霉和简青霉吸附Pb2 离子的最适pH值均为5,吸附Cd2 离子时均为3.二者对Pb2 离子的吸附均在4 h达到平衡,吸附量分别为29.07 mg·g-1和36.65 mg·g-1.Cd2 离子吸附也在约4 h达到最大吸附量,分别为26 mg·g-1和26.5mg·g-1.溶液中Zn2 离子和Cd2 离子的存在都会降低Pb2 离子的吸附量.2种吸附剂对Pb2 离子的吸附都符合Langmuir等温线模型,而对Cd2 离子的吸附都较为符合Freundlich等温线模型.1 mol/L HNO3对吸附有Pb2 离子的黑曲霉和简青霉进行解吸,解吸率分别可达77.4%和92.3%.  相似文献   

4.
研究了亚胺基二乙酸树脂(D401)吸附钐(Ⅲ)离子性能,在HAc-NaAc缓冲体系中pH为5.73时,树脂吸附钐(Ⅲ)离子的吸附最好,其静态饱和吸附容量为190mg/g树脂;用0.5~2.0 mol/L HCl溶液作解吸剂,解吸率为100.0%.  相似文献   

5.
采用熟化-浸出-萃取法从黄磷电炉电尘浆中提取镓   总被引:3,自引:0,他引:3  
在硫酸、盐酸直接浸出镓实验的基础上,进行硫酸直接浸出镓的动力学模拟,研究一种利用浓硫酸恒温熟化预处理、以磷酸三丁酯(TBP)为萃取剂从黄磷电炉电尘浆中提取镓的方法.研究结果表明镓浸出过程符合表面化学反应控制;提取镓的适宜实验条件是当反应体系中硫酸浓度为6.5 mol/L,液固比为3-2,200 ℃恒温熟化2.5 h,然后于90 ℃水浴中搅拌浸出1.5 h,镓的浸出率为90%左右;以TBP 为萃取剂在6.0 mol/L HCl 体系中萃取镓,萃取率达99%;以1 mol/L NaCl 为反萃剂,在有机相与水相的体积比为2-1 的条件下,反萃率在98%以上;经过进一步浓缩、纯化,可以获得含镓4.5 g/L 的富集物.  相似文献   

6.
海泡石对污染土壤镉、锌有效态的影响及其机制   总被引:13,自引:0,他引:13  
通过土壤原位钝化与等温吸附试验, 研究了海泡石黏土矿物对污染土壤中镉、锌有效态及 pH 对海泡石吸附镉、锌的影响。结果表明: 海泡石黏土矿物加入土壤后, 显著降低了土壤中水溶态镉、锌和可提取态镉、锌含量。在海泡石最大施用量( 土重的4%) 时, 水溶态镉、锌含量分别比对照下降了57. 3% 和41. 4% ; 而可提取态镉、锌含量分别比对照下降42. 8% 和24. 7% 。海泡石对 Cd2+ 和 Zn2+ 的吸附过程符合 Langmuir 和 Freundich 等温吸附方程所描述的规律。随着体系 pH 升高, 海泡石对镉、锌的吸附能力增强, 在 pH 为 6, 海泡石对 Cd2+和 Zn2+ 的最大吸附量分别为 12. 3 mg/ g和6. 80 mg/g, 海泡石对2种金属离子的吸附能力为 Cd2+ > Zn2+ 。海泡石作为土壤重金属钝化剂,施入土壤后能有效地降低土壤中 Cd2+ 和Zn2+的活性;而pH是控制海泡石的钝化能力强弱的关键因素。  相似文献   

7.
N-(2-羟乙基)哌嗪溶液吸收/解吸SO_2的性能研究   总被引:1,自引:0,他引:1  
文章通过亚硫酸钠溶液研究SO32-浓度和添加不同阴离子对溶液中S(Ⅳ)氧化率的影响。通过静态法和加热法分别研究N-(2-羟乙基)哌嗪溶液吸收/解吸SO2的性能,并推测了N-(2-羟乙基)哌嗪溶液吸收/解吸SO2的机理。结果表明,SO32-浓度在0.08~1.0 mol/L范围内,随着SO32-浓度的增大,S(Ⅳ)氧化率明显降低,当SO32-浓度高于1.0 mol/L,S(Ⅳ)的氧化率降低程度减小;Cl-、SO42-、PO43-和SO32-离子均能够降低S(Ⅳ)的氧化率,且差别不大。选用50%的N-(2-羟乙基)哌嗪溶液吸收SO2,溶液中SO32-浓度高,可有效地抑制溶液中S(Ⅳ)的氧化,解吸率达80.5%,且实验结果与所推测的N-(2-羟乙基)哌嗪溶液吸收/解吸SO2机理相一致。  相似文献   

8.
钙基蒙脱石对氟离子吸附及解吸实验   总被引:1,自引:0,他引:1  
一般根据研究认为粘土中的氟以可交换态的形式存在,对环境中氟的迁移具有重要意义,可用1M MgCl2进行提取,但其有效性却未进行验证.在不同初始pH和初始质量浓度条件下,但用钙基蒙脱石进行氟吸附.实验表明:钙基蒙脱石对氟的吸附与初始pH呈负相关关系,而与溶液初始质量浓度呈正相关关系.同时用MgCl2对粘土吸附的氟进行解吸,其解吸率在0%~30%之间,低初始氟质量浓度(<20 mg/L)时氟主要交换蒙脱石中的OH2基团,中初始氟质量浓度(20 mg/L~100 mg/L)时氟主要交换蒙脱石中的OH基团而与Al结合,高初始氟质量浓度(>100mg/L)时氟主要是与层间Ca结合,由于Al结合态氟稳定性最强,导致用1M MgCl2解吸粘土吸附的氟时中等初始质量浓度氟的解吸率最低.  相似文献   

9.
氟离子选择电极法测啤酒中的氟   总被引:1,自引:0,他引:1  
本文采用氟离子电极法测定啤酒中的氟 ,测量溶液的酸度为PH5— 6,用总离子强度调节缓冲液 ,消除干扰离子及酸度的影响 ,方法回收率 96.1 2 %~ 99.2 4 % ,线性范围为 1 0 - 1 mol/L~ 5× 1 0 - 7mol/L ,最低检出浓度 0 .0 1 μg/ml,本法操作简单、快速 ,适合作常规测定 .  相似文献   

10.
黄姜中鼠李糖的提取   总被引:4,自引:0,他引:4  
以黄姜为原料对鼠李糖的提取工艺进行了研究.实验表明,采用发酵法对黄姜水解液预处理,可有效除去溶液中的葡萄糖.通过优化实验,得到分离提取鼠李糖的最佳条件为:水解液为50g/L稀硫酸溶液,水解时间2h;酵母菌发酵的pH值为6,发酵时间2h;黄姜中鼠李糖的提取率为1.5%.经薄层层析、核磁共振氢谱分析表明,制备的产品是鼠李糖.  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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

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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