Solvent extraction of the ion-pairs of chromium(VI) and molybdenum(VI) with trioctylmethylammonium chloride and benzyldimethylcetylammonium chloride

Ohashi, Kousaburo

doi:10.1016/0039-9140(84)80243-x

Cited by 9 publications

(3 citation statements)

References 6 publications

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“…The concentration of the residual chromate in the aqueous phase after extraction was determined by spectrophotometry using 1,5-diphenylcarbazide, which forms an intense red-violet complex in the presence of chromate with an absorption maximum at 540 nm. ,− The corresponding concentrations after extraction using Cu(NO 3 ) 2 /4-OctpzH and Cu 3 (μ 3 -OH)(μ-4-Octpz) 3 (NO 3 ) 2 (H 2 O)] were 97(±5) and 68(±5) ppb, respectively. Because quaternary ammonium salts (including trioctylammonium, which forms during the nanojar-forming reaction as a side-product) are also known to extract chromate from aqueous to organic solutions (although under highly acidic conditions), − chromate extraction was also tested with Oct 3 NH + NO 3 – alone. In this case, the residual chromate concentration was 247(±5) ppb, indicating that Oct 3 NH + alone is not as good an extraction agent as nanojars.…”

Section: Resultsmentioning

confidence: 99%

“…An alternative way of removing chromate from water is by liquid–liquid extraction into an immiscible organic layer using extracting agents such as quaternary ammonium salts, − trioctylphosphine oxide, tributyl phosphate, and calixarenes. − This method offers recyclability and easier recovery of the extracted chromate. However, it is difficult to transfer CrO 4 2– (which is the dominant form of chromate at neutral and alkaline pH values) from water into organic solvents due to its large hydration energy (Δ G h ° = −950 kJ/mol) .…”

Section: Introductionmentioning

confidence: 99%

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Chromate Incarceration by Nanojars and Its Removal from Water by Liquid–Liquid Extraction

et al. 2023

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The unprecedented liquid−liquid extraction of the dinegative chromate ion (CrO 4 2− ) from neutral aqueous solutions into aliphatic hydrocarbon solvents using nanojars as extraction agents is demonstrated. Transferring chromate from water into an organic solvent is extremely challenging due to its large hydration energy (ΔG h °= −950 kJ/mol) and strong oxidizing ability. Owing to their highly hydrophilic anion binding pockets lined by a multitude of hydrogen bond donor OH groups, neutral nanojars of the formula [cis-Cu II (μ-OH)(μ-4-Rpz)] n (n = 27−33; pz = pyrazolate anion; R = H or n-octyl) strongly bind the CrO 4 2− ion and efficiently transfer it from water into n-heptane or C 11 − C 13 isoalkanes (when R = n-octyl). The extracted chromate can easily be recovered from the organic layer by stripping with an aqueous acid solution. Electrospray ionization mass spectrometric, UV−vis and paramagnetic 1 H NMR spectroscopic, X-ray crystallographic, and thermal stability studies in solution and chemical stability studies toward NH 3 , methanol, and Ba 2+ ions are employed to explore the binding of the CrO 4 2− ion by nanojars. Titration of carbonate nanojars [CO 3 ⊂ {Cu(OH)(pz)} n ] 2− with H 2 CrO 4 leads to anion exchange and the formation of chromate nanojars [CrO 4 ⊂ {Cu(OH)(pz)} n ] 2− . Details of chromate binding by H-bonding based on single-crystal structures of (Bu 4 N) 2 [CrO 4 ⊂ {Cu(OH)(pz)} 28 ], four pseudopolymorphs of (Bu 4 N) 2 [CrO 4 ⊂ {Cu(OH)(pz)} 31 ], and also the methoxy-substituted derivative (Bu 4 N) 2 [CrO 4 ⊂ {Cu 31 (OH) 30 (OCH 3 )(pz) 31 }] are presented.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Chromate Incarceration by Nanojars and Its Removal from Water by Liquid–Liquid Extraction

et al. 2023

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“…Therefore, the maximum extraction degree, E max , and the type of diluent have been basely used to compare the efficiency of a commonly used reactive extractant. The reported maximum uptake capacities of some common commercial carriers and the corresponding diluents used as solvation media for the chromium complexes are summarized as follows: Alamine 336 ( E max = 99.5%, xylene); Aliquat 336 ( E max = 95%, kerosene and xylene); tetrabutylammonium bromide ( E max = 95%, CH 2 Cl 2 ); tetrabutylammonium iodide ( E max = 99%, MIBK); diphenyl carbazide ( E max = 90%, isoamyl alcohol); tribenzyl amine ( E max = 98.5%, toluene); benzyldimethylcetylammonium chloride ( E max = 80%, CHCl 3 ). The present extraction method based on both the Alamine 300/xylene and DOA/xylene systems provide relatively large Cr(VI) uptake capacities of 99.8% for Alamine 300 and 94.5% for DOA in HCl media.…”

Section: Results and Discussionmentioning

confidence: 99%

Optimal Extractive Separation of Chromium(VI) from Acidic Chloride and Nitrate Media by Commercial Amines: Equilibrium Modeling Through Linear Solvation Energy Relation

Şenol

2013

Ind. Eng. Chem. Res.

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Data for the extraction of chromium, Cr(VI), from aqueous acidic chloride and nitrate solutions by Alamine 300 (tertiary amine)/xylene and di-n-octyl amine (DOA)/xylene solvent systems (298 K) have been subjected to formulation of an optimization structure for an effective Cr(VI) separation. The optimization approach uses a derivative variation method to efficiently identify the optimization range through analyzing the first-order derivatives of the optimized quantity and the nonlinear deviation profile of the derivative value. The main characteristics of it are simplicity and suitability for generalization. Optimum Cr(VI) removal efficiencies, defined both experimentally and analytically, range from about 70 to 90% for Alamine 300 and from 50 to 70% for DOA, being dependent about equally strongly on the types and concentration levels of the amine, acid, and the transferred Cr(VI) species. These dependencies are rationalized in terms of the interactions that take place in the equilibrium phases. Three independent variables, i.e. the concentrations of the amine, acid, and Cr(VI), are adequate for expressing the nonlinear dependence of the optimized extraction factor (E, Z t) on the properties of relevant system. Modeling efforts based on the LSER (linear solvation energy relation) principles and the mass–action law methodology have shown considerable success. The proposed LSER-based solvation model using nine physical descriptors of the solvent and ion provides relatively reliable fits with a mean error of 9%, and satisfies established limiting behavior of the physical event. A critical comparison of the present method with the other commonly used reactive extraction methods on an efficiency basis has been carried out.

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Extractive separation and determination of chromium in tannery effluents and electroplating waste water using tribenzylamine as the extractant

Kalidhasan

Ganesh

Sricharan

et al. 2009

Journal of Hazardous Materials

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Solvent extraction of the ion-pairs of chromium(VI) and molybdenum(VI) with trioctylmethylammonium chloride and benzyldimethylcetylammonium chloride

Cited by 9 publications

References 6 publications

Chromate Incarceration by Nanojars and Its Removal from Water by Liquid–Liquid Extraction

Chromate Incarceration by Nanojars and Its Removal from Water by Liquid–Liquid Extraction

Optimal Extractive Separation of Chromium(VI) from Acidic Chloride and Nitrate Media by Commercial Amines: Equilibrium Modeling Through Linear Solvation Energy Relation

Extractive separation and determination of chromium in tannery effluents and electroplating waste water using tribenzylamine as the extractant

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