溶剂气浮法去除水中的刚果红的研究

以十六烷基三甲基溴化铵为表面活性剂, 与阴离子型染料刚果红形成缔合物, 对该缔合物的溶剂气浮过程进行研究. 研究多种参数对溶剂气浮过程的影响, 如气浮速率、共存溶质的量、pH等参数对溶剂气浮去除率的影响. 研究表明表面活性剂与染料的物质的量之比为2∶1, 约24 min水中刚果红的去除率可达97%;NaCl会大大降低溶剂气浮的去除率;溶剂气浮的速率随着气流速率的增加而增加, 但高速率反而降低溶剂的去除率;共存溶质乙醇存在会使去溶剂去除率降低, 有机溶剂的量对溶剂气浮影响较小;pH中性去除率最佳;考察了不同温度下溶剂气浮的热力学及动力学, 研究表明, 溶剂气浮过程遵从一级动力学, 计算了该过程中的气浮表观活化能为7.48 kJ/mol.     

Study of a mathematical model of metal ion complexes in solvent sublation

Separation of metal ion complex, [(C(12)H(8)N(2))(3)Fe(2+)], with surfactant sodium dodecylphrate (DLS) complex from aqueous phase was carried out by solvent sublation, which obeys first-order kinetics. On the base of the complete transport mechanisms, the Langmuir adsorption, and the ion complex equilibrium in the aqueous phase, a mathematical model for the [(C(12)H(8)N(2))(3)Fe(2+)]-surfactant ion complex is obtained with the aid of the Mathematic 4.0 program, 4th Runge-Kutta method, and the Matlab programs. The effects of many parameters, such as K(a), K(l), K(ow), d(i), V(o), V(w), and Q(a), on solvent sublation are investigated. Furthermore, the simulation showed that the model is substantiated for experiments on the solvent sublation of the complex.     

The removal of humic acids from water by solvent sublation

The application of solvent sublation in the removal of humic acids was investigated in the present study. The humic acids (HA) were removed from an aqueous solution by solvent sublation of humic acid-hexadecylpyridium chloride (HPC) complex (sublate) into isopentanol. Several parameters were examined towards the optimization of humic acid removal; the dosage of a surfactant was found to be the major one, controlling the overall efficiency of the progress. The removal rate was somewhat enhanced by higher airflow rate and almost independent of the volume of the organic solvent floating on the top of the aqueous column. The effects of electrolytes (e.g., NaCl), nonhydrophobic organics (e.g., ethanol), and pH of the solution upon the process were studied. Under the optimized condition, the treatment performance was found to be very efficient, reaching almost 100%, indicating that solvent sublation can serve as a possible alternative technology for the removal of humic acids. The solvent sublation process follows first-order kinetics. A characteristic parameter, apparent activation energy of attachment of the sublate to bubbles, was estimated at a value of 9.48 kJ/mol. Furthermore, the simulation of a mathematical model with the experiments on the solvent sublation of humic acid-HPC was described here.     

溶剂浮选法分离富集污水中痕量羧酸类和胺类有机污染物的研究

本文报道了溶剂浮选法分离富集污水中痕量羧酸类有机污染物和胺类有机污染物的新方法。考察了溶液的pH值、通气速度、离子强度、浮选时间、相比以及不同溶剂对浮选效果的影响。在优化了浮选条件下溶剂浮选效率达到95％以上。采用本法对石化工业污水中的痕量羧酸类和胺类物质进行分离富集和鉴定,证明了该法的可行性。     

Studies on the mechanism of Indigo Carmine removal by solvent sublation

Indigo Carmine (C16H8N2Na2O8S2), an anionic dye, was removed from aqueous solution by solvent sublation of Indigo Carmine-cetyltrimethylammonium bromide (CTAB) complex (sublate) into 2-octanol. A stoichiometric amount of surfactant (surfactant:dye=2:1) was demonstrated to be able to remove over 93% IC from the aqueous solution in 5 min. The apparent activation energy of attachment of the sublate to bubbles was calculated as 1.3 kJ/mol. Parameters were considered. At the same time, on the base of the complete transport mechanism, a mathematical model for the dye-surfactant complexation was obtained. Furthermore, the simulation of the mathematical and experimental data was made with good results.     

The kinetics and thermodynamics of surfactants in solvent sublation

Solvent sublation has been performed on very dilute solutions of one cationic surfactant, hexadecylpyridinium chloride (HPC), and one anionic surfactant, dodecylbenzenesulfonic acid (LBS). Some thermodynamic values were obtained, e.g. molecular areas, A0, which are 50.0 and 47.7 A2/molecule, respectively, for HPC and LBS, and free adsorption energies, delta G(o)ads, which are -33.17 and -43.58 kJ mol(-1), respectively, for HPC and LBS. The kinetics were determined for a range of temperatures and gas flow-rates. Although the processes of solvent sublation of the two surfactants obey first-order kinetics, the respective adsorption mechanisms of HPC and LBS in the solvent sublation process were different. The pH and the presence of KCl and ethanol had no effect on the solvent sublation of LBS. The apparent active energy was calculated as 8.11 kJ mol(-1).     

Critical bubble radius in solvent sublation

The complex compound of dithizone-Co(Ⅱ) was separated and concentrated from the aqueous phase to n-octanol by solvent sublation.From the analysis of the coalescence behavior of bubbles on water-organic interface,the conception of critical bubble radius was proposed,and the value of the critical bubble radius in the water-octanol system was obtained:1.196×10~(-3)m.The simulation of the mathematical model using CBR and experimental data is completed with perfect results,and the simulation of the mathematical model using CBR is very different with the classic one.The analytical results proved that the critical bubble radius should be adequately considered in mathematical model of solvent sublation.     

Solvent Effect upon Ion-pair Extraction of Different Sodium Dyes Using Some Crown Ethers

Liquid-liquid extractive-spectrophotometric studies of sodium ion complexes of 18-crown-6(18C6), dibenzo-18-crown-6(DB18C6), 15-crown-5(15C5), and 12-crown-4(12C4) and anionic dyes [4-(2-pyridylazo)-resorcinol monosodium salt monohydrate (PAR), Eriochrom Black T (EBT), and methyl orange (MOR)] and sodium picrate (PICRAT) as the counter ion are described. The overall extraction equilibrium constants for the 1 : 1 complexes of the above crown ethers with sodium dyes between different organic solvents and water have been determined at 25deg;C. They were conducted in various solvent-water systems maintaining an identical initial cation concentration in water, [M0+]w, and macrocyclic ligand concentration in the organic phase, [L0]org}, so that in all extractions [M0+]w : [L0]org ratios were 1 : 1, 1 : 10, 1 : 20, 1 : 50, and 1 : 62.5. An ion association complex formed between the sodium-crown ether complex ion and a dye anion was extracted into the organic solvent, and then the dye concentration of the separated aqueous phase was measured with an ultraviolet-visible spectrophotometer. PAR was the best associated dye with all crown ethers sodium-dyes and the extracted dye occurs as the ion-pair complex. Methylene chloride was found to be better than other extractive solvents used in this study.     

Adsorptive Bubble Separation of Dinitrophenol

Dinitrophenol was removed from aqueous solution by various adsorptive bubble separation techniques. Foam fractionation of dinitrophenol with hexadecyltrimethylammonium bromide(HTA) was most effective with over 99% removal in 15 min. The addition of a surfactant in greater than stoichiometric amounts was required for effective separation. Solvent sublation of the dinitrophenol-HTA complex was also effective. The separation efficiency of solvent sublation of dinitrophenol-HTA was similar to that of foam fractionation. The separation by solvent sublation of dinitrophenol without adding any surfactant was very poor. Adsorbing colloid flotation with Fe(OH)₃ was not effective in removing dinitrophenol from aqueous solution.     

溶剂气浮法分离水中的Zn离子的研究

以双硫腙为配体,溴化十六烷基三甲基铵（CTAB）为表面活性剂。对Zn离子在无机相中形成的Zn-双硫腙-CTAB体系的溶剂气浮进行了研究。研究表明表面活性剂与Zn离子的物质的量之比为5：1,约1h水中的锌离子去除率可达98％。0．5mol／L NaCl大大提高体系的溶剂气浮的去除率,溶剂气浮的速率随着气流速率的增加而增加,共存溶质乙醇存在会使去除率降低,有机溶剂的量对溶剂气浮影响较小,溶剂气浮过程遵从假一级动力学。考察了不同温度下溶剂气浮的回收速率,计算了该过程中的气浮表观活化能为9．037kJ／mol。     

The kinetics and thermodynamics of surfactants in solvent sublation

Solvent sublation has been performed on very dilute solutions of one cationic surfactant, hexadecylpyridinium chloride (HPC), and one anionic surfactant, dodecylbenzenesulfonic acid (LBS). Some thermodynamic values were obtained, e.g. molecular areas, A₀, which are 50.0 and 47.7 Ų/molecule, respectively, for HPC and LBS, and free adsorption energies, ΔG°_ads, which are –33.17 and –43.58 kJ mol^–1, respectively, for HPC and LBS. The kinetics were determined for a range of temperatures and gas flow-rates. Although the processes of solvent sublation of the two surfactants obey first-order kinetics, the respective adsorption mechanisms of HPC and LBS in the solvent sublation process were different. The pH and the presence of KCl and ethanol had no effect on the solvent sublation of LBS. The apparent active energy was calculated as 8.11 kJ mol^–1.     

Determination of pyrethroid pesticide residues in vegetables by solvent sublation followed by high-performance liquid chromatography

A novel method is developed for separating and enriching pyrethroid pesticides from vegetables by solvent sublation, and determination of the pyrethroids is performed by high-performance liquid chromatography (HPLC). The effects of organic solvent, pH of the solution, nitrogen flow rate, and sublation time on the sublation efficiency of pyrethroids are investigated in detail, and the optimal conditions of the solvent sublation are selected. The floated product of vegetables in the optimal conditions is determined by HPLC. The limit of detection values range from 1.4 microg/kg (for bifenthrin) to 4.2 microg/kg (for fenpropathin). The recoveries of spiked vegetable samples are from 85.7% to 110.4%, and relative standard deviation values are from 1.70% to 6.19%. The results are satisfactory.     

Effect of water droplet in solvent sublation

Aqueous phase layer around bubble and water droplet are two additional processes in solvent sublation. In the dynamic process of mass transfer, they are always neglected, but they are very important in the investigation of thermodynamic equilibrium. In this paper, the effect of water droplet in solvent sublation was discussed in detail, and the previous mathematical model of solvent subaltion was improved. Matlab 6.5 was used to simulate the process of water droplets, and the comparison between the previous hypothesis and the improvement in this paper showed the superiority, especially in the investigation of thermodynamic equilibrium. Moreover, the separation and concentration of the complex compound dithizone-Co（Ⅱ） from aqueous phase to n-octanol by solvent sublation also proved the improved mathematical model was reasonable.     

溶剂浮选分离富集麻黄草中有效成分

采用溶剂浮选法分离富集麻黄草中的有效成分。考察了浮选溶剂、氮气流速、试液pH、浮选时间及电解质NaCl等因素对浮选效率的影响,优选出最佳浮选条件;对最佳条件下的浮选结果进行了评价,并与溶剂萃取法进行了对照;对麻黄草有效成分的浮选过程进行了初步探讨,浮选过程符合一级动力学方程。     

Solvent Sublation for Surface-Active Substances from Aqueous Solution,Comparison with Solvent-Extraction

The solvent sublation technique, a non-foaming technique, is originated by Sebba^[1] as an option for ion flotation, in which the surface active solute in water is adsorbed on the surface of ascending bubbles and then collected in an immiciable solvent As we know that there are a number of features that make the technique more advantageous than that of the solvent extraction:the possibility of easy handling of large volumes of aqueous sample; the equilibrium state established not in the bulk of system but only at the aqueous-organic interface and the recovery of trace elements eventually reaching 100%; no emulsion formation^[2-3]. Furthermore, the effluent water from a sublation column doesn't require further treatment to remove residual solvent. The handles are single and expenses are cheap, so the solvent sublation has the potential in the environmental treatment and the separation and preconcentration process^[4-6]. The aim of this paper is to investigate the experimental possibilities of the solvent sublation and its intercomparison with conventional liquid-liquid extraction, in order to get more information on widely applications in the near future.     

溶剂浮选法分离富集葛根中大豆甙元的研究

采用溶剂浮选法分离富集葛根中的大豆甙元。考察了浮选溶剂、氮气流速、试液pH、浮选时间及电解质（KC1）等因素对浮选效率的影响,优选出最佳浮选条件;对最佳条件下的浮选效果进行了评价,并与溶剂萃取法进行了对照,前者明显优于后者。     

Characteristics of proflavine solubilized in complexes of anionic polymers with a cationic surfactant

Absorption and emission spectra of 3,6-diaminoacridine (proflavine) are reported in mixed solutions of dodecyltrimethylammonium bromide (DTAB) with various polyelectrolytes including the sodium salts of poly(acrylic acid) (PAA). poly(methacrylic acid) (PMA), poly(styrenesulfonic acid) (PSS), poly(garacturonic acid) (pectate), and the alternating copolymers of maleic acid with ethylene (PMA-E) and styrene (PMA-S). The spectral change indicates the association of the dye (blue-shift) on these polyions except on PSS, the easy dissociation of the aggregated form into the monomeric form and the solubilization into the hydrophobic PMA-S/DTAB complex (red-shift), the little dissociation in the PAA/DTAB, PMA/DTAB and PMA-E/DTAB complexes, and the liberation of the bound dye in the case of pectate/DTAB complexes. In the PSS system, the strong interaction of the dye with the styrene groups induces the completely different spectral behavior. These results are discussed with the cooperative binding of the dye and the surfactant ion.     

溶剂浮选法分离富集茶叶中茶多酚的研究

采用溶剂浮选法分离富集了茶叶中的茶多酚。考察了浮选溶剂、氮气流速、试液pH及浮选时间等因素对浮选效率的影响,优选出最佳浮选条件;对最佳条件下的浮选效果进行了评价,并与溶剂萃取法进行了比对,前者明显优于后者。     

精氨酸的溶剂浮选分离技术及其分离机制

以表面活性剂十二烷基苯磺酸为捕收剂(DBSA),二(2-乙基己基)磷酸酯(P204)为萃取剂,正庚烷为有机溶剂,采用溶剂浮选法对水溶液中精氨酸进行分离富集,并与气浮络合萃取法、泡沫浮选法和溶剂萃取法进行了比较.结果表明,在常温下,0.09 g/L精氨酸水溶液250 mL、初始pH 7.0,DBSA浓度0.15 g/L,正庚烷体积10 mL, P204体积4.5 mL,气体流量200 mL/min,溶剂浮选法分离水溶液中精氨酸的富集比为16.2,回收率为97.2%.溶剂浮选法分离精氨酸的动力学实验结果表明,精氨酸的溶剂浮选过程阶段性明显,大致可分为3个阶段,第一阶段和第二阶段都符合一级动力学方程,第三阶段符合零级动力学方程,探索了溶剂浮选法分离精氨酸的分离机制.     

Solute-solvent and solvent-solvent interactions in the preferential solvation of 4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide in 24 binary solvent mixtures

The molar transition energy (E(T)) polarity values for the dye 4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide were collected in binary mixtures comprising a hydrogen-bond accepting (HBA) solvent (acetone, acetonitrile, dimethyl sulfoxide (DMSO), and N,N-dimethylformamide (DMF)) and a hydrogen-bond donating (HBD) solvent (water, methanol, ethanol, propan-2-ol, and butan-1-ol). Data referring to mixtures of water with alcohols were also analyzed. These data were used in the study of the preferential solvation of the probe, in terms of both solute-solvent and solvent-solvent interactions. These latter interactions are of importance in explaining the synergistic behavior observed for many mixed solvent systems. All data were successfully fitted to a model based on solvent-exchange equilibria. The E(T) values of the dye dissolved in the solvents show that the position of the solvatochromic absorption band of the dye is dependent on the medium polarity. The solvation of the dye in HBA solvents occurs with a very important contribution from ion-dipole interactions. In HBD solvents, the hydrogen bonding between the dimethylamino group in the dye and the OH group in the solvent plays an important role in the solvation of the dye. The interaction of the hydroxylic solvent with the other component in the mixture can lead to the formation of hydrogen-bonded complexes, which solvate the dye using a lower polar moiety, i.e. alkyl groups in the solvents. The dye has a hydrophobic nature and a dimethylamino group with a minor capability for hydrogen bonding with the medium in comparison with the phenolate group present in Reichardt's pyridiniophenolate. Thus, the probe is able to detect solvent-solvent interactions, which are implicit to the observed synergistic behavior.