首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 187 毫秒
1.
刘佳  常希俊 《光谱实验室》2013,30(5):2436-2440
研究了新型吸附材料铬蓝黑R(钙试剂)负载改性的活性炭对样品中Cr(Ⅲ)和Pb(Ⅱ)的固相萃取(SPE)并用电感耦合等离子体-原子发射光谱法(ICP-AES)进行检测.优化了pH值、吸附剂用量、流速等条件以达到定量吸附(≥95%),同时研究了洗脱剂的最佳洗脱条件以及共存离子干扰等问题.本法测定Cr(Ⅲ)和Pb(Ⅱ)的检出限分别为0.91ng·mL-1和0.65ng·mL-1,将其应用于土壤沉积物、猪肝、黄河水中的Cr(Ⅲ)和Pb(Ⅱ)含量的测定,加标回收率在98%-101%之间;用于测定标准物质中Cr(Ⅲ)和Pb(Ⅱ)的含量,结果与标准物参照值一致.  相似文献   

2.
NMR imaging is employed to study the preparation of supported catalysts and a number of mass transport processes in porous catalysts and sorbents. It is shown that, similar to Pt, adsorbed Pd leads to the increase of the relaxation times of liquids permeating porous alumina supports. A faster penetration of adsorbed water into the sorbent is observed when water vapor sorption by selective water sorbents is carried out under vacuum as compared to the sorption from moist air. An interruption of the capillary flow of water within the monolithic catalyst is shown to lead to a non-uniform drying along the monolith channels. Flow imaging of water inflowing into the monolith has revealed a complicated flow pattern characterized by the existence of counterflows in the entrance region.  相似文献   

3.
双硫腙包覆钛酸锶钡粉体对水中镉的吸附性能   总被引:7,自引:1,他引:6  
用草酸盐化学共沉淀法合成钛酸锶钡粉体,用双硫腙对该粉体表面进行包覆修饰,制成新型有机包覆吸附剂。用傅里叶变换红外光谱对包覆粉体进行了表征;以火焰原子吸收为检测手段,研究了该吸附剂对水中Cd2+ 的吸附性能,考察了洗脱条件;通过红外光谱,初步探讨了包覆和吸附作用机理。结果表明,双硫腙以氢键作用牢固地包覆于钛酸锶钡粉体上;该包覆粉体对水中的Cd2+具有较高的选择性吸附能力,其吸附量受介质的pH值影响,当pH值小于3时,该吸附剂对水中的Cd2+几乎不吸附,当pH值大于6时,吸附量达到最大;常温下,20 min内吸附达到平衡;吸附在双硫腙包覆钛酸锶钡粉体上的Cd2+,可用5% EDTA溶液完全洗脱。建立了吸附富集,火焰原子吸收法测定水中Cd2+的新方法,方法检出限为0.2 μg·L-1,相对标准偏差为2.9%。应用于自来水和地表水中Cd2+的测定,结果满意。  相似文献   

4.
翟云会  阮晓芳  王振  翁姣 《光谱实验室》2011,28(4):2042-2046
制备了表面修饰2,6-二氨基吡啶试剂的新型复合磁性Fe3O4纳米粒子,采用红外光谱对其进行了表征,并以火焰原子吸收光谱法(FAAS)测定其对水中Cu^2+和Zn^2+等重金属离子的静态吸附性能,考察了溶液pH值、平衡时间、吸附物初始浓度、洗脱条件等对复合材料吸附性能的影响。结果表明,复合材料在pH6—7时可对水中Cu^2+和Zn^2+产生有效吸附,5min内即可达到吸附平衡,等温吸附数据符合Langmuir单分子层吸附模型,T=298K,pH=7,V=50mL时对两种离子的饱和吸附量分别为45mg.g^-1和32mg.g^-1,重复使用6次其饱和吸附能力未见明显下降。  相似文献   

5.
火焰原子吸收法研究纳米钛酸锶钡粉体对铅的吸附性能   总被引:15,自引:1,他引:14  
以氯化钡、氯化锶和四氯化钛为原料,以草酸作共沉淀剂,采用化学共沉淀法制备了纳米复盐吸附剂——钛酸锶钡粉体,并利用TEM,XRD和FTIR进行了表征。以火焰原子吸收为检测手段,详细考察了该纳米吸附剂对水中铅的吸附性能。结果表明:该法合成的钛酸锶钡粉体外形以棒状为主,平均粒径为36 nm,为纯净的钙钛矿纳米粉体。该纳米粉体对水中的铅具有较强的吸附能力,吸附量受介质的pH值影响较大,当pH值为6.0时,该吸附剂对水中铅的吸附容量可达13 mg·g-1。吸附于纳米钛酸锶钡上的铅可用0.5 mol·L-1的硝酸完全解脱。建立了纳米钛酸锶钡粉体吸附富集,火焰原子吸收法测定水中痕量铅的新方法,该法检出限为11 μg·L-1,相对标准偏差为2.6%。用于地表水中铅的测定,结果满意。  相似文献   

6.
The sorption of methylene blue as a basic dye onto cellulosic materials such as waste newspaper was examined kinetically in the presence of ultrasound (sono-sorption) and in its absence (conventional method). The effects of various experimental parameters such as the amount of sorbent, type of cellulosic sorbents, initial dye concentration, temperature, and contact time have been investigated using a batch sorption technique. The information obtained can be used for treating effluents from the dye industry which deals with this kind of dye. The results show that as the amount of sorbent is increased, the dye removal in conventional method increases accordingly. In case of sono-sorption, it was stopped at specific amount of sorbent. More than 98% removal of the dye could be achieved in a very short period of time of sonication with respect to the conventional method. This behavior is related to the cavitation process which facilitates the removal of dye from aqueous solution. The method mentioned could be employed as a low cost alternative to the commercial activated carbon currently used in wastewater treatment for the removal of dyes.  相似文献   

7.
本文采用3种方法制备了新型复合CaO/MgO吸收剂,考察了不同制备方法对复合钙基吸收剂碳化/煅烧循环反应性能的影响。结果表明,不同制备方法能决定了钙基吸收剂中CaO颗粒与MgO颗粒在微观层面上的不同均匀混合程度,因此得到吸收剂的性能差异巨大。采用溶胶凝胶燃烧合成法制备的CaO/MgO吸收剂的性能明显优于其他两种常见方法...  相似文献   

8.
In this work, an experimental study aimed at the assessment of the factors affecting the adsorption of trichloroethylene (TCE) from water solutions onto activated carbons is presented. The influence of sorbent properties, such as B.E.T. surface area, micropore volume, chemical composition and acid/basic surface functional groups on TCE adsorption capacity is experimentally assessed by testing a set of 12 sorbents. Moreover, the effect of the presence of other species in solution, such as sodium acetate and tetrachloroethylene (PCE), is studied through parametric TCE adsorption isotherms realization. The experimental results show that the TCE adsorption capacity is promoted by a high B.E.T. surface area, micropore volume and C content and it is significantly affected by the presence of a non-ionic compound of similar structure (PCE), however it does not depend on the presence of an organic salt (sodium acetate). These results confirm that neither TCE-carbon ionic interaction nor sorbent ionization phenomena are involved in the TCE adsorption, since its mechanism is based on dispersion forces (London-Van Der Walls interaction). A thorough analysis of the experimental data set suggests that, in consideration of the TCE adsorption mechanism, the maximization of basal plane extent (as the B.E.T. surface area) and its effective fraction (as the C content) is a valid criterion to select or synthesize a new suitable sorbent for TCE adsorption from waters.  相似文献   

9.
S.F. Lim 《Applied Surface Science》2007,253(13):5772-5775
A new calcium-alginate magnetic sorbent has been prepared by an electrostatic extrusion technique. The sorbent has the calcium alginate as a bio-polymeric shell and iron oxides as magnetic cores. It is characterized by a multifunctional property: ease in separation via magnetic force, and effective adsorption of arsenic(V) and copper ions. It has been found that the equilibrium time of copper and arsenic(V) can be attained in less than 3 and 25 h, respectively. The maximum adsorption capacities of arsenic and copper ions are 6.75 and 60.24 mg/g, respectively, which are much higher than those of commercial adsorbents. Solution pH plays a key role in adsorption. The adsorption of arsenic increases as the pH is decreased. On the other hand, higher pH can enhance adsorption of copper ions.  相似文献   

10.
The aim of this work was to examine the effect of thermal treatment on organoclay sorptive properties. Aqueous sorption of nitrobenzene used as a probe compound was studied on Na-montmorillonite and two types of HDTMA-montmorillonite (where HDTMA is n-hexadecyltrimethyl ammonium exchanged by 41 and 90% of the clay cation exchange capacity) heated in air at 150, 250, 360 and 420 °C. Mild heating of sorbents (at 150 °C) results in a distinct increase of their sorptive efficacy. Treatment of organoclays at higher temperatures (250 and 360 °C) results in the significant sorbent changes as revealed by a C loss, decrease of a basal spacing and disappearance of symmetric and asymmetric stretching vibrations of CH2 but has a little impact on the sorptive efficacy (as compared with organoclays treated at 150 °C). Hence, even a significant carbon loss in thermally treated organoclays should not be necessarily linked to the loss of their sorptive potential. Further increase of the treatment temperature results in a decrease of a sorptive efficacy of all sorbents. Mild heating of organoclays in air could be useful for improving their sorptive potential. This improvement is assumed to result from the weakening of water-sorbate competition for sorption sites on a mildly heated sorbent.  相似文献   

11.
高效液相色谱法测定食品中阿斯巴甜的含量   总被引:1,自引:0,他引:1  
样品经水提取后,在ODS-3色谱柱上以磷酸二氢钾水溶液(10mmol/L,pH=3.5)和乙腈以85∶15的比例作为流动相进行色谱分离,用HPLC法VWD210nm处检测食品中阿斯巴甜的含量。本方法在标准浓度1.0—50.0μg/mL范围内,相关系数大于0.999,该方法适合日常检测。  相似文献   

12.
A highly porous calcium carbonate (calcite; sorbent 1) was used as a support for modification with α-FeOOH (calcite/goethite; sorbent 2), α-MnO2 (calcite/α-MnO2; sorbent 3) and α-FeOOH/α-MnO2 (calcite/goethite/α-MnO2; sorbent 4) in order to obtain a cheap hybrid materials for simple and effective arsenate removal from aqueous solutions. The adsorption ability of synthesized adsorbents was studied as a function of functionalization methods, pH, contact time, temperature and ultrasonic treatment. Comparison of the adsorptive effectiveness of synthesized adsorbents for arsenate removal, under ultrasound treatment and classical stirring method, has shown better performance of the former one reaching maximum adsorption capacities of 1.73, 21.00, 10.36 and 41.94 mg g−1, for sorbents 14, respectively. Visual MINTEQ equilibrium speciation modeling was used for prediction of pH and interfering ion influences on arsenate adsorption.  相似文献   

13.
以纳米二氧化硅(Nano-SiO2)为原料,硅烷偶联剂(KH-550)作为交联剂首先合成了氨丙基纳米二氧化硅(Nano-APSG),然后加入有机功能试剂季磷盐(COOH-Ph-CH2-P(C6H5)3Br)通过有机合成反应合成有机功能试剂改性纳米二氧化硅材料(Si|(CH2)3-NH-CO-Ph-CH2-P(C6H5)3Br),利用红外、粒径、热重分析等对结构进行了表征.通过火焰原子吸收光谱法研究此有机功能试剂改性纳米二氧化硅材料对水中Cr2O12-离子的吸附行为,考察了吸附的最佳pH、震荡时间、吸附剂用量等因素的影响,实验结果表明,在pH1,吸附剂用量为0.1 g,震荡时问为30 min时吸附剂对Cr2O72-离子的吸附效率可达95%以上,实验结果表明这种新型的功能材料可实现对废水中Cr2O72离子的分离与处理.  相似文献   

14.
A microfabricated magnetic sifter has been designed and fabricated for applications in biological sample preparation. The device enables high-throughput, high-gradient magnetic separation of magnetic nanoparticles by utilizing columnar fluid flow through a dense array (∼5000/mm2) of micropatterned slots in a magnetically soft membrane. The potential of the sifter for separation of magnetic nanoparticles conjugated with capture antibodies is demonstrated through quantitative separation experiments with CD138-labeled MACS nanoparticles. Capture efficiencies ranging from 28% to 37% and elution efficiencies greater than 73% were measured for a single pass through the sifter.  相似文献   

15.
Magnetic properties were added to original materials via impregnation with magnetic fluids, layer-by-layer (LbL) assembly of magnetite nanoparticles with polyelectrolytes or admixing to adhesive solutions. Thin multilayers with controllable thickness were formed on glass surfaces and lignocellulose fibers by the LbL method. Magnetic sorbents were created by impregnation of activated charcoal with a magnetite magnetic fluid stabilized with triethanolamine oleate. A mechanism of sorbent interaction with the nanoparticles is proposed. Possible application of these aqueous magnetic fluids for the formation of glutinous magnetic layers on metallized foil is demonstrated.  相似文献   

16.
In this research, ferroferric oxide nanoparticles were coated with silicon dioxide and further functionalized with alizarin complexone as the adsorbent of magnetic solid-phase extraction, thus aiming for extraction and preconcentration of heavy metals in Gastrodiae rhizoma samples. The determination of heavy metals was carried out by flame atomic absorption spectrometry. The results showed that the functionalized magnetic nanoparticles demonstrated higher extraction efficiency for copper, lead, and cadmium. The synthesized magnetic sorbents were characterized by transmission electron microscope, X-ray diffraction, and Fourier-transformed infrared spectra. Different parameters influencing the extraction efficiency including the amount of sorbent, sample pH, sorption time, solution volume, elution solvent, and reuse times were optimized. Under the optimal conditions, the method detection limit was 0.18, 0.25, and 0.12 µg/L for copper, lead, and cadmium, respectively. The proposed method was successfully applied to extract copper, lead, and cadmium in Gastrodiae rhizoma samples, and the recoveries of the samples ranged from 90.0 to 102.0% and relative standard deviations (n = 5) were in the range of 1.93–3.82%.  相似文献   

17.
黄志坚  孙军强 《光学学报》1998,18(6):67-772
对掺饵光激光器的自脉冲行为进行了研究。采用半导体激光器连续光泵浦,在较低的泵浦功率下,在掺饵光纤激光器中得到了稳定的1倍周期和2倍周期自脉冲输出,观察到周期性的不等幅脉冲序列输出,在理论上动用光子寿命可变的正交偏振激光场耦合模型对实验进行了分析。结果表明,掺饵光纤激光器中两正交偏振模光子寿命的调节对获得稳定的自脉冲有着十分重要的作用。  相似文献   

18.
《Current Applied Physics》2020,20(2):344-351
Oil spills are a major threat to the marine ecosystem, requiring immediate solutions to remove spilled oil from oceanic environments. In this study, we report a superhydrophobic molybdenum disulfide (MoS2) coated polydimethylsiloxane (PDMS) sponge and demonstrate its high proficiency in spilled oil recovery and oil spill detection based on oil-water separation ability. This novel oil sorbent is fabricated by a simple dip-coating to incorporate MoS2 flakes into PDMS sponge. The optimized MoS2-sponge displays a water contact angle of >152°, demonstrating excellent superhydrophobicity and high oil absorption (>97 wt%) for a variety of oils, including vegetable oil and fuel waste. Moreover, the material retains excellent oil absorption capability upon repetitive compression cycles. The versatility of this novel sorbent has been extended for the real-time spontaneous detection of oils by taking advantage of electrically conductive MoS2 layers.  相似文献   

19.
利用超高效液相色谱串联质谱技术检测啤酒原料麦芽中的赤霉酸(Gibberellic acid,GA3)。样品由乙腈/水(80/20)提取后,经Oasis MAX固相萃取柱净化,以甲醇-甲酸水为流动相,梯度洗脱下,经选择离子模式(SIR)检测。结果表明,赤霉酸在ACQUITY UPLCTMBEH C18色谱柱上(2.1mm×100mm,1.7μm)得到较好分离,回收率为70%—78%,检出限0.6μg/L,RSD≤8.9%,该方法适用于麦芽等复杂体系中微量赤霉酸的检测。  相似文献   

20.
钾基CO2吸收剂再生反应特性   总被引:5,自引:0,他引:5  
通过热重分析试验研究了钾基 CO2 吸收剂的再生反应特性.深入分析了气氛、分解终温和升温速率对再生转化率和分解反应速率的影响.通过热分析方法求取了反应动力学参数.研究发现,其分解终温最佳值为 200℃;CO2 和H2O 在分解终温较低时对反应过程的影响较大;升温速率对反应的影响程度在其高于 10℃/min 后明显减弱;KHCO3分解反应的表观活化能为 90~120 kJ/mol.本文为干法 K2CO3/KHCO3 循环脱除 CO2 的研究提供了一定的基础数据.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号