Tri-n-octylmethylammonium Chloride Research Articles

Solvent Extraction of Copper and EDTA in Electroless Copper Plating Wastewater Using a Quaternary Ammonium Salt

To separate both copper and 2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetic acid (EDTA) from the waste electroless copper plating solution by solvent extraction, the liquid–liquid equilibria of the copper-EDTA complex and unbound EDTA ion were experimentally measured. An organic solution of tri-n-octylmethylammonium chloride (TOMACl) was used as solvent. The kerosene solution of TOMACl could extract both copper-EDTA complexes and EDTA ions from the model wastewater. The fractional removal and distribution ratios of both the copper-EDTA complex and EDTA ions decreased as the pH increased. The valence number of the major copper-EDTA complex or EDTA ion in the aqueous phase increased with pH, and the number of TOMA+ cations required to chelate the complexes and ions increased. These complexes and ions had lower reactivity with TOMACl owing to steric hindrance. These effects caused lower removal of both copper and EDTA in a higher pH range, which is a typical condition of waste electroless copper solution.

Statistical Optimization of Lactic Acid Extraction Using Green Solvent and Mixed Extractants (TOA and TOMAC)

Since some previous years, reactive extraction has become more attractive and competitive technique for the separation and purification of lower carboxylic acids from fermentation broth as well as from dilute aqueous streams. This paper shows the results of investigation of reactive extraction of lactic acid (LA) from an aqueous solution using the synergistic mixture of the extractants (TOA (tri-n-octylamine) and TOMAC (Tri-n-octylmethylammonium chloride)) and a non-toxic and biocompatible green solvent (soybean oil). Three-level Box-Behnken design (BBD) under response surface methodology (RSM) was opted for the experimental design and to interpret the mutual effect of seven independent process parameters on the LA distribution coefficient (KD). The maximum values of LA distribution coefficient (KD=2.51) and its extraction efficiency (ηη=71.5%) were obtained for the optimum values of various process parameters such as 0.02 [M] initial LA concentration (CC1), 0.5 (v/v) extractant ratio (α), 28.66% (v/v) mixed extractants concentration (ψ), 2 (v/v) phase ratio (φ), 270C temperature (T), 102 rpm stirring speed (ω), and 63 mincontact time (τ). This present investigation will provide a noble discussion on LA reactive extraction using green solvent and on various influencing process parameters for gaining the enhanced value of LA distribution coefficient (KD).
 Chemical Engineering Research Bulletin 21(2019) 20-35

Efficient and environment-friendly vanadium (V) extraction from vanadium shale leachate using tri-n-octylmethylammonium chloride

In this work, an efficient and environmentally friendly method for recovering V (V) from vanadium shale leachate using an ionic liquid, tri-n-octylmethylammonium chloride (TOMAC), was proposed. The main factors affecting the extraction and stripping of vanadium using TOMAC were studied. A significant quantity (93.18%) of vanadium was extracted with almost no impurities under the following conditions: the concentration of TOMAC was 20 vol%; the concentration of 2-octanol as the phase modifier was 15 vol%; the phase ratio (O/A) was 1:10. More than 90% of vanadium in the loaded organic phase could be stripped quantitatively using a mixed solution of 0.8 mol/L NaOH and 1.2 mol/L NaCl. The stripping and regeneration of the loaded organic phase could be carried out in one step. Meanwhile, the anion exchange mechanism of extraction and stripping was analyzed by Fourier transform infrared (FT-IR) spectroscopy. Moreover, the organic phase stripped by the NaOH–NaCl synergistic stripping system maintained a relatively high extraction efficiency (>90%) even across many cycles, which indicated that the developed system is environmentally friendly and efficient for the recovery of vanadium.

Highly efficient separation and extraction of vanadium from a multi-impurity leachate of vanadium shale using tri-n-octylmethylammonium chloride

An efficient separation and extraction method for the recovery of V (V) from a sulfuric acid leaching solution of vanadium shale was developed using the ionic liquid tri-n-octylmethylammonium chloride (TOMAC). In this study, the main factors affecting the extraction of vanadium using TOMAC were investigated. Under optimum conditions, including a TOMAC concentration of 20 vol%, initial aqueous phase pH of 1.8, phase ratio (O/A) of 1:10, and extraction time of 2 min, 98.1% of vanadium was separated by a three-stage extraction, while almost no other impurities were extracted. The V (V) present in the scrubbed organic phase could be quantitatively stripped using 1.0 mol/L NaOH. Moreover, the extraction mechanism using TOMAC was analyzed by Fourier transform infrared (FT-IR) spectroscopy as well as the slope method. The obtained results supported the existence of an anion exchange mechanism between the Cl− atoms of TOMAC and H2V10O284− (HV10O285−) within the extraction system.

A new emulsion liquid membrane based on a palm oil for the extraction of heavy metals.

The extraction efficiency of hexavalent chromium, Cr(VI), from water has been investigated using a vegetable oil based emulsion liquid membrane (ELM) technique. The main purpose of this study was to create a novel ELM formulation by choosing a more environmentally friendly and non-toxic diluent such as palm oil. The membrane phase so formulated includes the mobile carrier tri-n-octylmethylammonium chloride (TOMAC), to facilitate the metal transport, and the hydrophilic surfactant Tween 80 to facilitate the dispersion of the ELM phase in the aqueous solution. Span 80 is used as surfactant and butanol as co-surfactant. Our results demonstrate that this novel ELM formulation, using the vegetable palm oil as diluent, is useful for the removal of hexavalent chromium with an efficiency of over 99% and is thus competitive with the already existing, yet less environmentally friendly, ELM formulations. This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5. Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water) does not significantly influence the extraction rate.

Formulation and characterization of Tween 80/cholestherol niosomes modified with tri-n-octylmethylammonium chloride (TOMAC) for carboxylic acids entrapment

The effects of different formulations on the physicochemical properties of unloaded and carboxylic acid-loaded niosomes are studied. Citric acid and lactic acid were the model carboxylic acids employed. The niosomes were prepared by ultrasonication of different formulations in a phosphate buffer at pH 2 and 7 containing Tween 80 (polyoxyethylene (20) sorbitan monooleate) and cholesterol as the vesicle forming agents. This study examines the effect of tri-n-octylmethylammonium chloride (TOMAC) on the degree of Tween 80 aggregation, acid entrapment efficiency, hydrodynamic size, and zeta potential of the formulated niosomes. Carboxylic acid entrapment efficiency may be explained in terms of interaction within the solubilization sites of the niosomes. TOMAC addition at pH 7 increased both the Tween 80 aggregation and citric acid entrapment efficiencies, but its effect on lactic acid entrapment was lower.

Performance evaluation of vanadium (IV) transport through supported ionic liquid membrane

Increasing use of vanadium in different industries including alloys and steel manufacturing, electrochemical coating and catalysts causes environmental concern about the toxic effluents. In the present research, the extraction of vanadium in supported ionic liquid membrane was studied. The effect of operational conditions on the process performance such as initial feed phase concentration, pH of the feed solution, pore size of the membrane support, type of ionic liquid charged on the support and stripping agent solution was investigated. Vanadium was effectively transported from the feed phase to the stripping phase of ammonia solution using the room temperature ionic liquid, tri-n-octyl methyl ammonium chloride (TOMAC) embedded in the support membrane. Selective transport of vanadium from its mixture with chromium ions was carried out applying TOMAC as carrier. It was also observed that addition of a slight amount of a second room temperature ionic liquid, 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] imide [BMIM][NTF2], improved the vanadium extraction process considerably.

A comparative study of experimental optimization and response surface optimization of Cr removal by emulsion ionic liquid membrane

A comparative study on the optimization of process parameters of an emulsion ionic liquid membrane (EILM) by experimental work and response surface methodology (RSM) has been carried out. EILM was prepared by using kerosene as solvent, Span 80 as surfactant, NaOH as internal reagent, a hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM] +[NTf 2] −) as a stabilizer and a second ionic liquid tri-n-octylmethylammonium chloride (TOMAC) as a carrier. The prepared EILM was used to separate and concentrate Cr from wastewaters. The comparison between the experimentally optimized and the RSM optimized values was accomplished by optimizing the following parameters: homogenization speed, carrier concentration, internal phase concentration, agitation speed, treat ratio, internal to membrane phase ratio, surfactant concentration and pH of the feed phase. The comparison showed that all the values were in good agreement except for the internal phase concentration and the treat ratio. It was observed that the stability provided by [BMIM] +[NTf 2] − decreased as the extraction progressed due to its high density. Nevertheless, a good stability could be obtained by the combination of [BMIM] +[NTf 2] − and Span 80 during extraction process.

Chromium removal by emulsion liquid membrane using [BMIM] +[NTf 2] − as stabilizer and TOMAC as extractant

A new type of emulsion liquid membrane (ELM) has been prepared to separate and concentrate chromium (Cr) from waste water. A hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM] +[NTf 2] −) is used in the membrane phase as a stabilizer to provide sufficient stability and a second ionic liquid Tri-n-octylmethylammonium chloride (TOMAC) as a carrier. The other components to prepare emulsion are kerosene as solvent, span 80 as surfactant and NaOH as an internal reagent. In the present experimental investigation, the effects of various parameters such as homogenization speed, carrier concentration, internal phase concentration, agitation speed, treat ratio, internal to membrane phase ratio, surfactant concentration, pH of the feed phase and ([BMIM] +[NTf 2] − concentration on the % removal of Cr have been reported. At an optimum condition, 97% percentage of Cr could be extracted. Results showed that the stabilizing effect of [BMIM] +[NTf 2] − keeps on decreasing as the extraction proceeds. However, the provided stability by the combination of [BMIM] +[NTf 2] − and span 80 has been found to be sufficient during the extraction process.

Electrochemical study and electrodeposition of copper in the hydrophobic tri-n-octylmethylammonium chloride ionic liquid media

The electrodeposition of metallic Copper in binary mixture ionic liquid/organic solvent (tri-n-octylmethylammonium chloride (TOMAC))/chloroform (CHCl 3) was investigated. The electrochemical behavior of Cu(II) in TOMAC/CHCl 3 at glassy carbon working electrode at room temperature was studied by cyclic voltammetry and spectroscopy impedance. The results from the cyclic voltammetry showed that the electrodeposition of metallic Cu in the binary mixture ionic liquid/organic solvent was an irreversible process and was controlled by the diffusion of Cu(II) on a glassy carbon working electrode. The average value of αn α was found to be 0.23 at 25 °C and the diffusion coefficient (D 0) of Cu(II) was calculated to be 7.12 10 − 9 cm 2/s at room temperature. The performance of TOMAC ionic liquid such as internal resistance has been investigated with electrochemical impedance spectroscopy (EIS). The scanning electron microscopy (SEM) micrographs was used to observe that the copper plating was moderately dense and contains fine crystallites with average sizes of about 1 μm at room temperature. Energy dispersive X-ray analysis (EDAX) profile showed that the obtained film was copper.

Emulsion stabilization using ionic liquid [BMIM] +[NTf 2] − and performance evaluation on the extraction of chromium

This study focuses on the role of a hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMIM] +[NTf 2] − in the preparation of emulsion liquid membrane (ELM) phase containing kerosene as solvent, Span 80 as surfactant, NaOH as internal phase and TOMAC (tri-n-octylmethylammonium chloride) a second ionic liquid as carrier. The first time used [BMIM] +[NTf 2] − in ELM was found to play the role of a stabilizer. The emulsion prepared using [BMIM] + [NTf 2] − has a long period of stability of about 7 h (at 3% (w/w) of [BMIM] +[NTf 2] −) which otherwise has a brief stability up to only 7 min. The stability of the emulsion increases with the increase in concentration of [BMIM] +[NTf 2] − up to 3% (w/w). Nevertheless, with further increase in concentration of [BMIM] +[NTf 2] −, a reduction in the stability occurs. The extraction experiments were carried out after holding the ELM for 2 h after the preparation and a removal efficiency of approximately 80% was obtained for Cr. The destabilization of the emulsion was studied by observing the change in the interface height. An empirical correlation for the stability of the emulsion has been proposed.

Electrochemical behavior of uranium(VI) in 1-butyl-3-methylimidazolium chloride and in 0.05 M aliquat-336/chloroform

Summary Alkali metal uranyl chloride (M2UO2Cl4 (M = Na or Cs)) was dissolved in 1-butyl-3-methylimidazolium chloride (bmimCl) and the redox behavior of uranyl ion present in the resultant solution was investigated by cyclic voltammetry at 343 K. The cyclic voltammogram consisted of a reduction wave occurring at the peak potential of −0.85 V, due to the reduction of U(VI) and two oxidation waves occurring at the peak potentials of −0.6 V and +0.2 V. Controlled potential electrolysis of uranium(VI) loaded bmimCl gave a black deposit, which was characterized as uranium oxide by EDXRF and XRD analysis. Extraction of uranium(VI) from nitric acid medium by 0.05 M tri-n-octylmethylammonium chloride (TOMAC) in chloroform was studied and the cyclic voltammogram of uranyl ion present in the extracted phase exhibited a single reduction (−0.8 V) and an oxidation wave (0.06 V) at 298 K. Controlled potential electrolysis of uranium(VI) loaded TOMAC at −1.0 V also gave a black uranium oxide deposit similar to that observed in the previous case. The results indicated that uranyl ion in organic phase undergoes a single step two electron quasi-reversible reduction at the working electrode, which can be conveniently exploited for the direct recovery of uranium from the spent fuel or from high level liquid wastes.

Reactive extraction of d, l-α-phenylglycine with a quaternary ammonium salt: Effect of hydroxide anions and water coextraction

The extraction equilibria of α-phenylglycine in alkaline solutions with tri- n-octylmethylammonium chloride (TOMAC) (10%, v/v) in 1-decanol as diluent have been studied. Hydroxide anion and water co-extraction were also investigated. Equilibrium constants for the extraction of phenylglycine and OH - ions have been determined experimentally at 20 °C, being K ePhg = 1.09 and K eOH = 0.30. A mathematical model has been developed to predict the equilibrium concentrations from initial conditions, the equilibrium constants and mass balances to the system. The model takes into account the coextraction of water (3.5 ± 0.4%, v/v) that was determined to be independent of feed concentration.

Extraction of fission palladium by Aliquat 336 and electrochemical studies on direct recovery from ionic liquid phase

The wide electrochemical window and ion exchange properties of a room-temperature ionic liquid (RTIL) have been exploited for the extraction of palladium from nitric acid medium into ionic liquid phase — followed by direct electrodeposition of the metal from the organic phase. Extraction of palladium by commercial Aliquat 336 ionic liquids, tri- n-octylmethylammonium chloride (TOMAC) and tri- n-octylmethylammonium nitrate (TOMAN), was studied as a function of [HNO 3], [NO 3 −] and [TOMAN]. The distribution ratio ( D Pd(II)) of palladium in TOMAN increased with an increase in the concentration of nitric acid and passed through a maximum at 1.0 M nitric acid. In contrast, the D Pd(II) value of palladium in TOMAC decreased continuously with an increase in the concentration of nitric acid. Substantial amounts of water and nitric acid were also co-extracted into the organic phase with palladium. The redox behavior of a solution of Pd 2+ extracted in 0.1 M TOMAN/CHCl 3 and 0.1 M TOMAC/CHCl 3 at glassy carbon working electrode was studied using cyclic voltammetry. The voltammogram consisted of a single reduction and an oxidation wave indicating that Pd 2+ was reduced to palladium metal by a single-step two-electron transfer at the working electrode. Controlled potential deposition of palladium on platinum electrode gave a black deposit, which was characterized to be metallic palladium. Interference of other fission products during extraction and electrodeposition of palladium is also reported.

Improved back extraction of papain from AOT reverse micelles using alcohols and a counter-ionic surfactant

The extraction of papain (MW 23 kDa, p I 9.6) from water was studied using reverse micelles containing sodium bis(2-ethylhexyl)sulfosuccinate (AOT). Forward extraction of papain was carried out in the pH range of 4.0–6.5 and a maximum extraction of 65–70% was observed at pH 6.3. Papain extracted into the micelles could be back extracted to only 30% into a conventional aqueous phase (high pH and high KCl concentrations). In order to improve the back extraction of papain, 8–10 vol% alcohols were added because it was known that alcohols have an effect on the micelle–micelle interactions. However, this way resulted in the loss of papain activity inspite of good back extraction yields (80–90%). The back extraction of papain encapsulated in AOT reverse micelles was then carried out by adding a counter-ionic surfactant tri- n-octylmethyl-ammonium chloride (TOMAC). This technique resulted in faster back extraction compared to conventional method. Around 80–90% of activity recovery was obtained after back extraction. The improved backward transfer was likely caused by electrostatic interaction between the oppositely charged surfactant molecules, which led to the collapse of reverse micelles.

Separation and Recovery of Cr(VI) from Simulated Plating Waste Using Microcapsules Containing Quaternary Ammonium Salt Extractant and Phosphoric Acid Extractant

The separation and recovery of Cr(VI) from a simulated plating waste aqueous solution, containing Cr(VI), Ni(II), Cu(II), and Zn(II), have been investigated, using microcapsules consisting of styrene−divinylbenzene copolymer and containing, as the extractant, tri-n-octylmethylammonium chloride (TOMAC) or bis(2-ethylhexyl)phosphoric acid (D2EHPA). The extractants were encapsulated successfully into the microcapsules by the addition of the extractants to the dispersed phase, during the polymerization process, and possess an extractability for the metals identical with that for the conventional liquid−liquid extraction system. Chromatographic operation, using a column packed with microcapsules, showed that perfect separation and recovery of toxic Cr(VI) was achieved with the TOMAC microcapsules, with further separation of the three other metals then being carried out with D2EHPA microcapsules.

Back extraction of lactic acid with microporous hollow fiber membrane

In this work, back extraction was considered a promising alternative to regenerate carboxylic acids of low-volatility into appropriate aqueous solution from organic phase. Identification of an efficient back extraction system for lactic acid recovery was focused on. Screening of back extraction reagents was first carried out by employing a wide variety of inorganic compounds. From the viewpoints of high stripping power, low cost and capability of simultaneously regenerating the extractant, aqueous sodium chloride solution was selected as the most suitable one for recovery of lactic acid from lactate–TOMAC (tri- n-octylmethylammonium chloride) complex. However, TOMAC and oleyl alcohol are likely to pose the troubling emulsion problem in conventional mixer–settler system. Therefore, non-dispersive back extraction of lactic acid from organic phase was attempted in a microporous hollow fiber (MHF) membrane device by aqueous NaCl solution. A satisfactory recovery was accomplished, signifying the great potential of integrating membrane back extraction with extractive fermentation process for lactic acid production.

Photoreductive stripping of vanadium using 2-propanol as radical scavenger in liquid-liquid extraction process of vanadium and molybdenum.

Photoreductive stripping of V in a liquid-liquid extraction process for separation of V and Mo was investigated. A halogen lamp or a low-pressure mercury lamp was used as a light source and 2-propanol was used as an OH radical scavenger. The pentavalent V was photoreduced to V(IV) and stripped selectively from tri-n-octylmethylammonium chloride (TOMAC)/benzene organic phase into HCl-NaCl aqueous phase. The separation factor of 170–250 was obtained by a single extraction-stripping process. The equilibrium relationship in the course of the stripping process was also investigated. The scheme of photoreductive stripping of V was formulated, taking the photoreduction in aqueous phase into consideration.

Electro-reductive stripping of vanadium in solvent extraction process for separation of vanadium and molybdenum using tri-n-octylmethylammonium chloride

The electro-reductive stripping of vanadium from benzene containing vanadyl and molybdate anions and tri-n-octylmethylammonium chloride (TOMAC) as extractant was studied. A two-compartment cell separated by a cation exchange membrane (Nafion 417) and equipped with platinum electrodes was used. The pentavalent vanadyl anion was reduced to tetravalent vanadyl cation at the aqueous phase/electrode interface and was stripped selectively, with the molybdenum remaining in the organic phase. At a low agitation speeds, such as 300 min −1, in both the organic and aqueous phases, the stripping rate was influenced by mass transfer of the vanadyl anion from the organic into aqueous phase, while it was influenced by diffusion and the electrochemical reduction of vanadyl ion at a higher agitation speeds. The organic solution after the electro-reductive stripping was reusable for the extraction of vanadium and molybdenum without any extra treatment.

Photoreductive Stripping of Vanadium in Solvent Extraction Process for Separation of Vanadium and Molybdenum.

The separation of vanadium and molybdenum by solvent extraction followed by photoreductive stripping was investigated, using tri-n-octylmethylammonium chloride (TOMAC) as extractant. A low-pressure mercury lamp and a halogen lamp were used as light sources. Pentavalent vanadium was reduced photochemically to tetravalent or trivalent vanadium in organic solution as well as in aqueous solution, using isopropyl formate as a radical scavenger. The photoreduction of vanadium in TOMAC/benzene phase containing vanadyl and molybdate anions allowed the vanadium to be stripped into an aqueous phase selectively, leaving the molybdenum in the organic phase. The stripping yield of vanadium reached 100%. The separation factor of vanadium and molybdenum by single extraction followed by single selective stripping was 1000–2000 when using the mercury lamp and 170–430 when using the halogen lamp. The organic solution was not damaged by the photoreductive stripping and was reusable for repeated extraction and stripping.