Eine schnelle Methode zur quantitativen Abtrennung von Chlor und Brom aus sauren wäßrigen Lösungen / A Rapid Method for the Quantitative Elimination of Chlorine or Bromine from Aqueous Acidic Solutions

1988 ◽  
Vol 43 (1) ◽  
pp. 134
Author(s):  
Wolfram Baumgärtner ◽  
Youssef A. Gawargious ◽  
Klaus Brodersen
Keyword(s):  
Aqueous Solutions ◽  
Rapid Method ◽  
Dilute Solution ◽  
Acidic Solutions

Abstract The quantitative elimination of chlorine and bromine from acidic aqueous solutions was achieved through extraction with a dilute solution of styrene in CCl4 .

scholarly journals Boron removal from aqueous solutions by a polyethylenimine-epichlorohydrin resin

2018 ◽  
Vol 83 (2) ◽  
pp. 251-264 ◽  
Author(s):  
Sofia Sarri ◽  
Panagiotis Misaelides ◽  
Dimitrios Zamboulis ◽  
Jolanta Warchoł
Keyword(s):  
Aqueous Solutions ◽  
Boron Concentration ◽  
Kinetic Studies ◽  
Alkaline Solutions ◽  
Competitive Sorption ◽  
Boron Removal ◽  
Boron Uptake ◽  
Acidic Solutions ◽  
Ph Values ◽  
Batch Technique

The use of a polyethylenimine?epichlorohydrin resin for the boron removal from aqueous solutions (boron concentration: 100?5000 mg L-1) of non-adjusted and pre-adjusted pH (pHnat, pHinit 8.0, 9.0 and 10.0) aqueous solutions was investigated using a batch technique. The boron concentration in the solutions after sorption was determined photometrically. The results indicated that the pH-dependent boron uptake was related to the protonation/deprotonation of the surface functional groups of the resin and to the boron speciation in solutions of different pH values. The maximum boron sorption capacity observed in solutions of pH 9.0 was 55 mg g-1 exceeding the majority of other commercial or alternative sorbents. Five empirical adsorption equations (Freundlich, Langmuir, Redlich?Peterson, Langmuir?Freundlich and Toth) were applied to the modelling of the boron adsorption equilibrium. The modelling results identified the homogenous boron sorption from acidic and heterogeneous from alkaline solutions. At alkaline pH, the system non-ideality can originate either from the different binding mechanism or from the competitive sorption of different boron species. The homogenous type boron sorption from acidic solutions was further confirmed by kinetic studies

The Photolysis of Aqueous-Solutions of Potassium Hexacyanoferrate(III)

1986 ◽  
Vol 39 (9) ◽  
pp. 1411 ◽  
Author(s):  
MW Fuller ◽  
KMF Lebrocq ◽  
E Leslie ◽  
IR Wilson
Keyword(s):  
Aqueous Solutions ◽  
Quantum Yields ◽  
Alkaline Solutions ◽  
Potassium Hexacyanoferrate ◽  
Thermal Reactions ◽  
Acidic Solutions

The photolysis of aqueous solutions of potassium hexacyanoferrate(III) at 254 and 366 nm forms aqua- or hydroxo-pentacyanoferrate(III) in both acidic and alkaline solutions, with quantum yields between 0.02 and 0.06. Subsequent thermal reactions form the decacyanodiferrate(III) and/or decacyanodiferrate(III,II) species, especially in weakly acidic solutions, and, in alkaline solutions, may precipitate hydrated iron(III) oxides.

scholarly journals 1-ALKYL-3-METHYL-4-HYDROXYIMINO-2-PYRAZOLINE-5-ONES AS EXTRACTION REAGENTS

2017 ◽  
Vol 60 (5) ◽  
pp. 30
Author(s):  
Andrey E. Lesnov ◽  
Peter T. Pavlov ◽  
Larisa V. Pustovik ◽  
Irina А. Sarana
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Alkaline Media ◽  
Acidic Solutions ◽  
Pyrazoline Ring ◽  
Maximum Extraction ◽  
Aliphatic Radical ◽  
Extraction Properties ◽  
Partition Constants ◽  
Methanolic Medium

With nitrosation of the corresponding 1-R-3-methylpyrazole-5-one (R = C4H9, C5H11, C6H13, C7H15, C8H17, C6H5) in acidic aqueous methanolic medium at 0-5 °C a series of 1-alkyl-3-methyl-4-hydroxyimino-2-pyrazolin-5-ones with a yield of 72-85% were synthesized. The compounds are soluble in CHCl3, C2H4Cl2, C6H5CH3, i-C4H9OH, CCl4, C2H5OH, slightly soluble in C6H14, H2O. They can be recrystallized from a mixture of C6H14: C6H5CH3 = 5: 1 or isooctane. The structure of the compounds was confirmed by the data of ECR, IR, Raman spectroscopy and TLC data. The interphase distribution of oxyiminopyrazolones between chloroform and aqueous solutions was studied as a function of pH. In alkaline media, the reagents completely transferred into the aqueous phase. In acidic solutions, up to 1 mol/l HCl, the compounds are in the organic phase. The maximum values of the partition coefficient are observed for the reagents with the maximum length of the aliphatic radical. The effect of the length of aliphatic radical at the first position of the pyrazoline ring on their extraction properties were studied by example of extraction of nickel and copper (II) ions. The length of the radical does not affect the composition of the recoverable complexes of nickel and copper (II). In all cases the ratio is close to 1:2. Extraction proceeds through a cation-exchange mechanism. Replacement of the phenyl radical in the first position of the pyrazoline ring by an aliphatic resulted to the increase in partition constants of the reagents between chloroform and aqueous solutions. The range of pH values of the maximum extraction of elements was widened. The capacity of the extractant for metals also increased. At the same time, the pH50 extraction values remained practically unchanged. In the case of 0.05 mol/l solution of 1-phenyl-3-methyl-4-oxyimino-2-pyrazolin-5-one in chloroform, when the extract was saturated with the metal ion, precipitation of the complex was observed.For citation:Lesnov A.E., Pavlov P.T., Pustovik L.V., Sarana I.A. 1-Alkyl-3-methyl-4-hydroxyimino-2-pyrazoline-5-ones as extraction reagents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 30-36.

scholarly journals Influence of pH on the Electropolymerisation of 2-Aminophenol and 2-Aminobenzyl Alcohol

2015 ◽  
Vol 18 (1) ◽  
pp. 037-041
Author(s):  
Ahmad S. Barham
Keyword(s):  
Aqueous Solutions ◽  
Benzene Ring ◽  
Polymer Films ◽  
Resonance Effect ◽  
Microelectrode Arrays ◽  
Hydroxyl Group ◽  
Amine Group ◽  
Acidic Solutions ◽  
Ph Values ◽  
Influence Of Ph

The electrochemical oxidation and polymerisation of 2-aminophenol and 2-aminobenzyl alcohol in aqueous solutions of different pH values has been studied. Polymer films of the studied monomers on gold electrodes were synthesized. The behaviour of both monomers is quite different, illustrating the resonance effect of the hydroxyl group being bound directly to the benzene ring for 2-aminophenol. For each compound it is shown that oxidation in acidic solutions is most difficult due to the protonation of the amine group. These polymer films can be used for applications such as corrosion protection and as structures from which textured electrodes, microelectrode arrays for example, can be generated.

scholarly journals Release of Cationic Drugs from Charcoal

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 683
Author(s):  
Chiara Di Ruocco ◽  
Maria Acocella ◽  
Gaetano Guerra
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Uv Spectra ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acidic Solutions ◽  
Cationic Drugs ◽  
Mild Conditions ◽  
Harsh Conditions

The goal of this research is to improve preparation of charcoal adducts in a manner suitable for cationic drug release, possibly using an eco-friendly procedure. Charcoal, widely commercialized for human ingestion, is oxidized by hydrogen peroxide in mild conditions. Adducts of a cationic drug (lidocaine hydrochloride, a medication used as local anesthetic) with charcoal are prepared after basification of charcoal and characterized mainly by elemental analysis, wide-angle X-ray diffraction, infrared spectroscopy and thermogravimetry. The drug in the prepared adducts is present in amount close to 30% by weight and can be readily released to both neutral and acidic aqueous solutions. Cation release, as studied by UV spectra of aqueous solutions, is faster in acidic solutions and is faster than for adducts with graphite oxide, which can be prepared only in harsh conditions.

Complexation of arsenate with ferric ion in aqueous solutions

RSC Advances ◽  
2015 ◽  
Vol 5 (126) ◽  
pp. 103936-103942 ◽  
Author(s):  
Jinqin Yang ◽  
Liyuan Chai ◽  
Mengqing Yue ◽  
Qingzhu Li
Keyword(s):  
Aqueous Solutions ◽  
Spectroscopic Techniques ◽  
Ferric Ion ◽  
Acidic Solutions ◽  
Ferric Arsenate ◽  
Higher Temperature

Ferric arsenate complexes (FeH2AsO42+ and FeHAsO4+) formed in acidic solutions were confirmed by UV-Vis spectroscopic techniques, which transformed into gel-like material under higher pH (pH ≥ 2.38) or higher temperature (T ≥ 90 °C) conditions.

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