scholarly journals Extraction of Alkali Ions Investigated by Conductometric and pH Measurements

10.14311/888 ◽  
2006 ◽  
Vol 46 (6) ◽  
Author(s):  
L. Kalvoda ◽  
R. Klepáček

Extraction of alkali ions from aqueous solutions of chlorides and hydroxides into a lipophilic liquid membrane composed of tetraethyl p-tert-butylcalix[4]arene tetraacetate (TBT) solution in hexane was investigated by means of measurements of changes in the electrolytic conductivity and pH-value of the aqueous solution. Hydrolysis of the TBT ionophore resulting in the release of the ethyl groups was proposed as the main reaction process, leading to disturbance of the known preference of TBT for sodium ions. 

2015 ◽  
Vol 72 (3) ◽  
pp. 478-483 ◽  
Author(s):  
Yunleiyu Guo ◽  
Tingting Shen ◽  
Chen Wang ◽  
Jing Sun ◽  
Xikui Wang

The removal of caffeine (CAF) in aqueous solution by peroxymonosulfate oxidant activated with cobalt ion was investigated under a variety of operating conditions. The effects of various operating parameters, such as oxone and Co2+ concentrations, pH value, and the coexistence of dissolved organic matter and inorganic anions on the removal of CAF have been investigated. The removal efficiency increased with the increase in the concentrations of oxone and Co2+ ion added. The additions of chloride, bicarbonate, and sodium humate have negative effects on the removal of CAF. Near-neutral condition (5.0 < pH < 7.0) is favorable for the removal of CAF. Based on our experiments, 100% degradation of 50 mg/L CAF can be achieved within 4 minutes under the conditions of 1.00 mM oxone and 0.10 mM Co2+ ion at pH 5.0–7.0.


2011 ◽  
Vol 356-360 ◽  
pp. 1675-1678 ◽  
Author(s):  
Wei Peng ◽  
Chun Jian Xu

Removal of phenol from aqueous solution by a new emulsion liquid membrane (ELM) system and its heat-induced demulsification have been investigated. The ELM consists of commercial kerosene as organic solvent, OP-4 as surfactant agent, hydrochloric acid as the stripping phase. Effect of different operating parameters such as internal phase concentration, surfactant concentration, stirring speed, PH value in external phase, volume ratio of membrane phase to internal phase and volume ratio of membrane phase to external phase were investigated for the removal of phenol from aqueous solution. At the optimum condition about 95.7% phenol is removed in less than 20min of contact time. The demulsification efficiency was investigated under different temperature and time and proved to be high at 80°C.


2020 ◽  
Vol 58 (5A) ◽  
pp. 170
Author(s):  
Bạch Long Giang ◽  
Lam Van Tan ◽  
To-Uyen T. Dao ◽  
Hong-Tham T Nguyen ◽  
Trinh Duy Nguyen

Recent interest in wastewater treatment has shifted to the use of agricultural waste to treat antibiotics in aqueous solutions due the economic efficiency the technique brings. This study focuses on the synthesis, properties and study of the kinetic mechanism of activated carbon and its potential application to remove antibiotics from aqueous solutions. Activated carbon is synthesized from sugarcane bagasse by activated method with active substance of ZnCl2. With a specific surface area of about 980.84 m2/g and high porosity, the product could absorb a large amount of ciprofloxacin (CIP) antibiotics. The properties of materials are characterized by relevant analytical techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET). The behavior of CIP adsorption was studied under the effect of adsorption dose, initial CIP concentration and pH value. The adsorption and isothermal mechanisms are also studied. The results show that the adsorption adhered to the second kinetic model and the experimental data was found to be reasonably fitted to the Langmuir isotherm. Therefore, activated carbon manufactured from sugarcane bagasse could be used as a potential adsorbent to effectively remove antibiotics from aqueous solution.


Author(s):  
Xiaoyan Wang ◽  
Jinmei Du ◽  
Changhai Xu

Abstract:: Activated peroxide systems are formed by adding so-called bleach activators to aqueous solution of hydrogen peroxide, developed in the seventies of the last century for use in domestic laundry for their high energy efficiency and introduced at the beginning of the 21st century to the textile industry as an approach toward overcoming the extensive energy consumption in bleaching. In activated peroxide systems, bleach activators undergo perhydrolysis to generate more kinetically active peracids that enable bleaching under milder conditions while hydrolysis of bleach activators and decomposition of peracids may occur as side reactions to weaken the bleaching efficiency. This mini-review aims to summarize these competitive reactions in activated peroxide systems and their influence on bleaching performance.


1984 ◽  
Vol 49 (3) ◽  
pp. 559-569 ◽  
Author(s):  
Jaroslav Nývlt

The metastable zone width of an aqueous solution of KCI was measured as a function of the time and temperature of overheating above the equilibrium solubility temperature. It has been found that when the experiments follow close upon one another, the parameters of the preceding experiment affect the results of the experiment to follow.The results are interpreted in terms of hypotheses advanced in the literature to account for the effect of thermal history of solution. The plausibility and applicability of these hypotheses are assessed for the given cause of aqueous solution of a well soluble electrolyte.


1983 ◽  
Vol 29 (8) ◽  
pp. 1513-1517 ◽  
Author(s):  
M W McGowan ◽  
J D Artiss ◽  
B Zak

Abstract A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.


1971 ◽  
Vol 26 (6) ◽  
pp. 543-545
Author(s):  
Leopoldo J. Anghileri ◽  
Esther S. Miller

The hydrolysis of 32P-sodium polyphosphates (linear and cross-linked) in aqueous solution has been studied. The radiometric determinations indicate that the ortho-phosphate formation is a slow reaction, and that the amount formed by the linear variety is higher than that produced by the cross-linked form. There is a significant formation of metaphosphates during the hydrolysis of the cross-linked polyphosphate which is missing or at least reduced to a much lesser extent in the case of the linear polyphosphate.


1879 ◽  
Vol 29 (196-199) ◽  
pp. 472-482 ◽  

In order to investigate this subject, I devised and constructed the following apparatus :—A and B are two thin glass basins, 81 millims. internal diameter (= 5,153 sq. millims. of mercury surface), and 6·0 centims. deep; each containing a layer of mercury about 1·0 centim. deep, covered by a layer, about 3 centims. deep, of the aqueous solution to be examined.


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