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排序方式: 共有453条查询结果,搜索用时 31 毫秒
1.
A new method for analysis of trace mercury in water samples was developed, based on the combination of preconcentration/separation using dithizone-modified nanometer titanium dioxide (TiO2) as a solid phase extractant and determination by cold vapor atomic adsorption spectrometry (CVAAS). Dithizone was dissolved with alcohol and loaded on the surface of nano-sized TiO2 powders by stirring. The static adsorption behavior of Hg2 on the dithizone-modified nanoparticles was investigated in detail. It was found that excellent adsorption ratio for Hg2 could be obtained in the pH range of 7-8 with an oscillation time of 15 min, and a 5 mL of 3.5 mol·L-1 HCl solution could quantitatively elute Hg2 from nanometer TiO2 powder. Common coexisting ions caused no obvious influence on the determination of mercury. The mechanisms for the adsorption and desorption were discussed. The detection limit (3σ) for Hg2 was calculated to be 5 ng·L-1. The proposed method was applied to the determination of Hg2 in a mineral water sample and a Zhujiang River water sample. By the standard addition method, the average recoveries were found to be 94.4%-108.3% with RSD (n = 5) of 2.9%-3.5%. 相似文献
2.
注聚井注入状况诊断方法研究 总被引:3,自引:3,他引:0
在室内试验和动态分析的基础上,对引起注聚井注入困难的原因进行了分析,提出了利用单井动态预测结果和实际注入动态曲线对比判断聚合物注入状况的方法,建立了预测注聚井注入动态的预测模型,并对数值模拟计算结果进行了分析。同时还评价了现场应用效果。通过数值模拟和实际注入动态曲线对比,可以初步判断待措施井有无近井地带堵塞,为提高注聚井压解堵措施的有效性奠定了基础。 相似文献
3.
Zeolite beta with a low SiO2/Al2O3 ratio was synthesized by a novel two-step process.The synthesized sample was characterized with XRD,SEM,FTIR,and N2 adsorption-desorption and solid-state MAS NMR.The results showed that aluminium species were inserted into the framework of zeolite beta.The BET surface area,volume,and particle size of the zeolite beta sample decreased with decreasing SiO2/Al2O3 ratio.Our process was proved an efficient route to synthesize zeolite beta with a low SiO2/Al2O3 ratio. 相似文献
4.
ZhangXiaojing QinRuyi LiuJinlong 《中国炼油与石油化工》2003,(4):31-35
This article refers to the procedure for selection, evaluation and development of the LADS-D desorption agent associated with the LADS-A adsorbent used in the non-hydroprocessing adsorptive desulfurization (LADS) process for FCC naphtha developed by LPEC Refining Research Institute. The LADS-D desorption agent can effectively remove the sulfides adsorbed on the LADS-A adsorbent. The saturated LADS-A adsorbent can be instantly regenerated by the LADS-D desorption agent to recover its adsorption activity. The LADS-D desorption agent can not only effectively remove all impurities adsorbed on the adsorbent, but also has strong ability to dissolve the impurities to keep a stable desorption efficiency of adsorbent to be basically commensurate with fresh adsorbent after extended use. 相似文献
5.
The sorption behavior of acid dyes onto cetyltrimethylammonium bromide (CTAB)-modified silica as a function of pH in the aqueous medium was studied. Single-and multi-solute sorption equilibria of orange Ⅱ(OR), phenol red (PR) and Eriochrome Black T (EBT) were studied at pH 3, unbuffered water pH and pH 11. Sorption behavior of EBT could not be conducted at pH3 due to its aggregation in acidic medium. All the reaction conditions, experimental protocols and techniques remained the same throughout the sorption process. Sorption isotherms for single-solute system were fitted by the Langmuir model, while Langmuir competitive model (LCM) and the ideal adsorbed solution theory (IAST) coupled with Langmuir model (IAST/Langmuir) were used for the prediction of multisolute competitive sorption. Sorption affinities influenced by the factors like physical interactive forces between the molecules of CTA on silica and sorbate, structural limitations of the dyes based on their geometrical arrangement were investigated. Sorption affinity of OR was found to be higher than that of EBT and PR at all the pH values investigated. Magnitude of the sorption capacities was observed to be higher in acidic medium but lower in alkaline medium. Trends of the sorption affinities in multisolute system were simlar to those in single-solute system but magnitude of the sorption capacities was significantly reduced due to the prevailing competition among the sorbates. 相似文献
6.
大量研究表明,壳聚糖、海藻和泥炭都是天然高分子物质,其结构中提供许多能与离子结合的活性官能团,对重金属离子都具有很强的吸附作用,且资源丰富,价格低廉,可广泛用于工业废水中重金属的去除与回收。在静态条件下用改性的壳聚糖、海带、泥炭吸附电镀废水中重金属离子Cr(Ⅵ),探讨了废水pH、吸附时间、吸附剂用量、铬液初始质量浓度对去除Cr(Ⅵ)效果的影响。结果表明,在废水pH为1.0—2.0, 相似文献
7.
8.
9.
冬艳 《军民两用技术与产品》2004,(12):28-28
北京东立银燕环保设备技术有限公司是专门从事环保设备和空调设备开发生产的股份制企业。该公司研制生产的DYJ型活性炭废气净化器,是一种干法废气净化设备,它利用活性炭的特殊吸附作用处理工业废气。其核心部件——活性炭吸附单元有独特的设计结构,具有风阻小、更换方便(可在设备正常运行情况下更换)、标准化设计等特点。 相似文献
10.
Mansour Moinpour Ashley Wayman Ashwani Rawat Colin T.Carver Edward E.Remsen 《功能材料与器件学报》2013,(4):186-189
荧光相关光谱(FCS)用于研究化学机械平坦化研磨液中添加剂-磨料粒子间的相互作用。通过添加剂和荧光探针分子,Alexa fluor 546(A546)在二氧化硅磨料粒子表面的竞争性吸附作用性质的描述,FCS提供了添加剂和磨料粒子间粘合的数量测定。胶态二氧化硅上吸附苯并三唑(BTA)的分析确认,A546被附加的BTA取代。但是,乙氨酸增强了胶态二氧化硅对A546的吸附。也证明了FCS是检测CMP工艺中使用的不同类型胶态二氧化硅磨料粒子间表面化学成分差异的灵敏技术。 相似文献