Triisooctylamine Research Articles

Amino-functionalized graphene oxide membranes for efficient separation of Sr2+ ions

Graphene oxide (GO) membranes were integrated with diverse nitrogen functional groups by subjecting to ammonia (NH3) vapours and evaluated for resultant changes in their chemical functioning and strontium (Sr) adsorption performance. Exposure to NH3 vapours amends the functional groups of GO, introduces amine, amide, ammonium functionalities and generates abundant sites prone to react with Sr2+ ions. The extent of GO restructuring and repercussions on Sr adsorption behaviour were examined using different GO precursors, NH3 treatment methods, membranes with varying GO mass and other nitrogen reagents namely, tri-isooctyl amine, pyridine, N,N-dimethyl acetamide. Nitrogen group functionalization enhances the Sr adsorption capacity of GO membranes nearly by two times, irrespective of the NH3 exposure duration and nature of precursor GO membranes. These NH3 subjected GO membranes displayed optimum Sr adsorption performance of ~475 mg/g, reusable at least for nine filtration cycles and importantly, capable of discharging 35–60 % of adsorbed Sr. The N-group supported Sr separation demonstrated in the present work is an energy efficient solid state membrane based procedure, which also lays a road map for development of amine, amide, ammonium functionalized GO layers and provides flexible platform for separation of all those toxic elements displaying affinity to complex with N-groups.

The Reaction Extraction Combining Crystallization for Growth of Sodium Chloride in a Spray Fluidized Bed Crystallizer

At present, the crystal size of sodium chloride prepared by a traditional crystallization process (such as stirred crystallization) is inhomogeneous, and it has a great quantity of fine grains in crystallizer. This work presents a novel approach for the growth of sodium chloride from supersaturated solutions by reaction-extractive crystallization in a spray fluidized bed crystallizer (SFBC), in which sodium sulfate solution is transformed into potassium chloride and sulphuric acid based on a reactive extraction-crystallization process using triisooctylamine (TOL) in n-octanol as the extraction system. This paper mainly studies the effect of operating conditions (e.g., circulation flow rate, velocity ratio of oil and aqueous phases, crystallization temperature, hydraulic residence time, and feed velocity) on the crystal size distribution (CSD) during the crystallization process of sodium chloride in a SFBC. Experimental results show that the optimum conditions are 1.0362 m/s as the best circulation flow rate, 9.5 : 8.5 as the best velocity ratio of oil and aqueous phases, 313 K as the best temperature, 4320 s as residence time, and 8 mL.min−1 as the best feed velocity. Meanwhile, the proposed extraction kinetic model about extraction rates is developed and validated against data from the SFBC. And it proves that the reactive extraction system is controlled by diffusion and chemical reaction. Analysis of the extraction kinetic model and comparison with experiments reveal that the extraction kinetic model results are in well agreement with experiments. Furthermore, the uniform and large crystals can be obtained in a spray fluidized bed crystallizer without special concentration since extraction and crystallization are carried out in the same equipment. In addition, all of the sodium chloride products prepared under the optimal conditions in SFBC show a better CSD performance than the stirred crystallization. This research demonstrates that this process enables controlling the crystal size in a rather wide range, thus further underlining the potential of this technique for applications in the crystallization industry.

Solvent extraction of indium(III) from HCl solutions by the ionic liquid (A324H+)(Cl−) dissolved in Solvesso 100

Indium(III) is extracted from HCl solutions (0.1–6 M HCl) by the ionic liquid (A324H+)(Cl−). The ionic liquid was generated in a previous reaction of the tertiary amine Hostarex A324 (triisooctyl amine) dissolved in Solvesso 100 with 1 M HCl solution. The metal extraction was investigated under various experimentalconditions: equilibration time, temperature, metal and HClconcentrations in the aqueous solution and ionic liquid concentration in the organic solution. Experimental results suggested that the indium extraction is due to an anionic exchange reaction between the chloride ion of the ionic liquid and the InCl4− of the aqueous solution. The performance of the system was compared against the extraction of other metals in binary solution (indium and accompanying metal) and against other ionic liquids. Indium(III) was stripped from metal-loaded organic solutions by the use of diluted hydrochloric acid solutions, and the precipitation of zero valent indium is possible by a further addition of sodium borohydride to the In-bearing strip solution.

Liquid–Liquid Equilibrium and Molecular Toxicity of Active and Inert Diluents of the Organic Mixture Tri-iso-octylamine/Dodecanol/Dodecane as a Potential Liquid Membrane for Lactic Acid Removal

Lactic acid can be in situ removed from a fermentation broth through reactive liquid extraction or a liquid membrane to enhance the fermentation process. The organic mixture tri-iso-octylamine (TiOA)/dodecanol/dodecane at 10 vol % of the amine is a potential organic mixture for lactic acid removal. Liquid–liquid equilibria with lactic acid aqueous solutions and molecular toxicity on the bacteria Lactobacillus casei ATCC 393 were measured with several dodecanol proportions in dodecane (0 to 90 vol %) and 10 vol % TiOA as potential solvents or membrane phases for LA removal from a fermentation broth. Effects of the organic phase on the bacteria as cell growth, biomass production, glucose consumption, productivity, and product to biomass yield are analyzed. Dodecanol increases the lactic acid chemical equilibrium constant for the liquid–liquid equilibria, while increasing the molecular toxicity on the bacteria. However, for dodecanol concentrations from 30 to 40 vol % the value of the chemical equilibrium co...

Utilization of a triacetylcellulose membrane to immobilize 5-(2′,4′-dimethylphenylazo)-6-hydroxypyrimidine-2,4-dione for erbium determination in real samples

A membrane optode formed by physical inclusion of a chromophore 2-amino-6-(1,3-thiazol-2yldiazenyl)phenol (ATDP) into a plasticized cellulose triacetate (CTA) matrix was investigated for preconcentration, extraction and colorimetric determination of Er(III) from aqueous samples. The optode was examined for erbium uptake in borate buffer medium (∼125ngmL−1) at pH 8.5–9.0. The inclusion of an anion-exchanger tri-isooctylamine (TiOA) was found to be necessary for the formation of Er(III)–ATDP complex in the optode matrix, resulting into distinct color change of the optode from red to violet color after erbium sorption. The composition of the optode was prepared by varying the amounts of different plasticizers and TiOA to obtain minimum response time towards Er(III) in borate buffer medium. The effects of different experimental parameters involved in the detection and quantification of Er(III) using optode were optimized. The optode analytical performance was performed in terms of interference of cations and anions, reusability, equilibration time, detection limit, etc. and compared with the conventional colorimetric method for Er(III) using different chromophores. The optode developed in the present study was tested in real samples with good results comparing to the GF-AAS method.

Recovery of hydrochloric acid from galvanizing industrial effluents

ABSTRACTThe recovery of hydrochloric acid and its separation from iron, zinc and minor elements, in the galvanizing pickling baths, were studied by solvent extraction (SX) and distillation and by distillation and crystallization. Several extractants were tested, the tri-isooctyl amine, Alamine 308, the primary aliphatic amine Primene JM-T and the mixture of four trialkylphosphine oxides, Cyanex 923. Only Cyanex 923 enabled distillation. The results indicated the feasibility of the processes to treat a real effluent using Cyanex 923 and to obtain high HCl concentrations in the distillate (256–330 g/L).

Rhenium(VII) solvent extraction with mixtures of tertiary amine and oxygen-containing extractants from sulphate media

The extraction of rhenium(VII) from sulfate media by mixtures of tri-iso-octylamine (TIOA) and oxygen-containing reagents (2-octanol, 2-octanone, phenetole) has been examined. The synergistic effect for mixtures of TIOA and electron-donor reagents (ketone, ether) was established. The maximal synergistic enhancement factor (3.1) was observed for the “TIOA-2-octanone” mixture. Rhenium(VII) was extracted by this mixture as (R3NH)ReO4∙0.2B. The maximal rhenium(VII) extraction was found at weak acid concentrations in aqueous phase (pH~2–3), whereas the “TIOA-ketone” mixture could extract rhenium(VII) from weak alkaline media (pH~7–9) in contrast to the “TIOA-alcohol” mixture.Effective stripping from the loaded “TIOA-2-octanone” mixture was achieved with a 3mol/L NH4OH in 2–3 stages.

Synergistic extraction of Cr(VI) from Ni(II) and Co(II) by flat sheet supported liquid membranes using TIOA and TBP as carriers

Abstract In present study, the synergistic separation of Cr(VI) has been investigated from synthetic acidic solution containing Cr(VI), Co(II) and Ni(II) by fl at sheet supported liquid membrane (FSSLM) technique using triisooctylamine (TIOA) and tri-n-butyl phosphate (TBP) as carriers. The main goal of the study was based in the exploring of the synergistic effect of TBP on selective extraction of Cr(VI) in presence of Co(II) and Ni(II) ions. The various parameters related with membrane and aqueous solution properties were studied to identify the optimum extraction and stripping conditions of the Cr(VI) through FSSLM. In the optimum conditions, initial mass flux (J0) and separation factors (βCr/Co and βCr/Ni) were obtained as 1.49 x 10-05 (kg/m2.s), 382.2 and 725.3 respectively from aqueous H2SO4 media through Celgard 2500 (Celgard Inc., USA) polymer support. As a result, the considerable synergistic infl uence on selective transport of Cr(VI) through FSSLM using TIOA and TBP as carriers has been identifi ed.

Automatic in-syringe dispersive liquid-liquid microextraction of ⁹⁹Tc from biological samples and hospital residues prior to liquid scintillation counting.

A new approach exploiting in-syringe dispersive liquid-liquid microextraction (DLLME) for (99)Tc extraction and preconcentration from biological samples, i.e., urine and saliva, and liquid residues from treated patients is presented. (99)Tc is a beta emitter with a long half-life (2.111 × 10(5) years) and mobility in the different environmental compartments. One of the sources of this radionuclide is through the use of its father (99m)Tc in medical diagnosis. For the first time a critical comparison between extractants and disperser solvents for (99)Tc DLLME is presented, e.g., tributyl phosphate (TBP), trioctylmethylammonium chloride (Aliquat®336), triisooctylamine (TiOA), as extractants in apolar solvents such as xylene and dodecane, and disperser solvents such as acetone, acetonitrile, ethanol, methanol, 1-propanol, and 2-propanol. The system was optimized by experimental design, and 22.5% of Aliquat®336 in acetone was selected as extractant and disperser, respectively. Off-line detection was performed using a liquid scintillation counter. The present method has a (99)Tc minimum detectable activity (MDA) of 0.075 Bq with a high extraction/preconcentration frequency (8 h(-1)). Urine, saliva, and hospital residues were satisfactorily analyzed with recoveries of 82-119%. Thus, the proposed system is an automatic powerful tool to monitor the entry of (99)Tc into the environment. Graphical Abstract (99m)Tc is widely used in Nuclear Medicine for diagnosis. Its daugther (99)Tc is automatically monitored in biological samples from treated patients by in-syringe dispersive liquid-liquid microextraction.

Development of an automated batch-type solid-liquid extraction apparatus and extraction of Zr, Hf, and Th by triisooctylamine from HCl solutions for chemistry of element 104, Rf

Abstract Solid-liquid extraction of the group 4 elements Zr and Hf, which are homologues of Rf (Z = 104), and Th, a pseudo homologue, by triisooctylamine (TIOA) from HCl solutions was performed by batch method. After examining the time required to reach extraction equilibrium for these elements in various concentrations of TIOA and HCl, we investigated in detail variations in the distribution coefficients (K d) with TIOA and HCl concentrations. The K d values of Zr and Hf increased with increasing the HCl and TIOA concentrations, suggesting an increase in the abundance of the anionic chloride complexes of Zr and Hf. On the other hand, the K d values of Th were low in all the HCl concentrations studied, implying that Th does not form anionic species dominantly. We developed a new automated batch-type solid-liquid extraction apparatus for repetitive experiments on transactinide elements. Using this apparatus, we performed solid-liquid extraction employing the radioactive nuclides 89mZr and 175Hf produced by nuclear reactions and transported continuously from the nuclear reaction chamber by the He/KCl gas-jet system. It was found that the distribution behaviors in 7–11 M HCl are almost constant in the time range 10–120 s, and the K d values are consistent with those obtained in the above manual experiment. This result suggests that the chemical reactions in the extraction process reach equilibrium within 10 s for Zr and Hf under the present experimental conditions. It took about 35 s for the extraction using the apparatus. These results indicate the applicability of the present extraction using the developed apparatus to 261Rf (T 1/2 = 68 s) experiments.

Solvent Extraction of Zirconium and Hafnium as Homologues of Rutherfordium by Triisooctylamine from HCl Solutions

Solvent extraction of the group 4 elements Zr and Hf, homologues of Rf (Z = 104), by triisooctylamine (TIOA) from hydrochloric acid (HCl) was performed by batch method using carrier-free radioisotope tracers. The times required to reach equilibria were determined, and then variations of the equilibrium distribution ratios (D) were investigated against the TIOA and HCl concentrations. It was found that the chemical reactions involved in the extraction of the chloride complexes of Zr and Hf by 0.1–1.0 M TIOA from 7.4–10.4 M HCl reached equilibrium in 10–20 min. The D values increased as the concentrations of HCl and TIOA increased, suggesting the formation of anionic chloride complexes of Zr and Hf. We obtained comparison data to study Rf-chloride complex formation. Although the reaction time in the extraction needs to be shortened, the extraction behavior of Rf could be investigated by solvent extraction under the present experimental conditions.

Enhancing performance of hybrid liquid membrane process supported by porous anionic exchange membranes for removal of cadmium from wastewater

In this study, polyethersulfone (PES)-based porous anionic exchange membranes (AEMs) are fabricated. The morphological and transport properties of the membranes such as pore size, roughness, porosity, water uptake, membrane transport number, fixed charge density, and conductivity are determined. These AEMs are used as supporting membranes to enhance the mass transfer flux in a hybrid liquid membrane (HLM) process for removal of cadmium from an acidic feed solution. The liquid membrane phase is prepared by dissolving triisooctylamine (TIOA) in kerosene. The effects of applying porous AEMs with different fixed charge densities, temperature, and initial cadmium concentration are investigated. It is confirmed that the main resistance in the mass transfer in the system is confined in the supporting membranes. Applying PES-based AEMs with a proper fixed charge density of X′=0.0197meq/cm3 instead of non-ionic PES supporting membranes can increase the mass transfer coefficient from 0.0068 to 0.017min−1. Almost all cadmium can be transferred within 3h. The proposed anionic supporting membranes can yield a much higher fluxes for removal of cadmium in high concentrations comparing to the same hybrid liquid membrane system with non-ionic PVDF supporting membranes while only insignificant loss in removal efficiency is observed.

Solvent extraction and separation of zinc and iron from spent pickle liquor

The present study reports liquid-liquid extraction and separation of zinc and iron values from a spent pickle solution. Tertiary amine viz. tri-iso-octyl amine (TiOA) or tris(2-ethylhexyl) amine (TEHA), in the absence and presence of di-(2-ethylhexyl)phosphoric acid (HDEHP), has been used for the separation of zinc and iron. Three aqueous solutions were investigated: i) HCl–Fe(II)–Fe(III), ii) Zn(II)–HCl, and iii) HCl–Fe(II)–Fe(III)–Zn(II) with the composition similar to that of pickle liquor (g/L) [117 Zn(II), 90 HCl, 30 Fe(II) and 1 Fe(III)]. Co-extraction of Zn(II), HCl and Fe(III) was noticed with the extractants (amine/amine+HDEHP) without any appreciable selectivity except for Fe(II) which was not extracted by the solvent. Zn(II) was extracted selectively leaving Fe(II) in the raffinate provided that Fe(III) was removed from the solution at a low O/A phase ratio or reduced to Fe(II) state. Stripping of HCl, Zn(II) and Fe(III) was also not selective with distilled water. The Zn(II) free raffinate containing Fe(II) was microbially oxidized to Fe(III) and was then quantitatively extracted in 3-stages with 30% Versatic 10 acid at the O/A phase ratio of 3.5:1. Loaded Fe(III) was easily stripped from the organic phase with dilute sulfuric acid. A flowsheet is proposed to produce high purity Zn(II) and Fe(III) solutions by solvent extraction.

A simple and sensitive separation technique of 99Mo and 99mTc from their equilibrium mixture

The present work describes a simple and inexpensive separation method of 99 Mo from the equilib- rium mixture. The liquid-liquid extraction technique has been employed to separate 99 Mo and 99m Tc using tri- isooctylamine (TIOA). The 99 Mo and 99m Tc were quanti- tatively separated out in 2 M TIOA with tripled distilled water; 99m Tc was back extracted from TIOA organic phase to aqueous phase by 0.1 M DTPA. The species information or indirect speciation of molybdenum was also established by the extraction profile of the molybdenum.

Selective recovery of cobalt(II) towards lithium(I) from chloride media by transport across polymer inclusion membrane with triisooctylamine

Abstract In this work the selective transport of cobalt(II) and lithium(I) ions from aqueous chloride solutions through polymer inclusion membranes (PIMs) is presented. Triisooctylamine (TIOA) has been applied as the ion carrier in membrane. The effects of various parameters on the transport of Co(II) and Li(I) were studied. The obtained results show that Co(II) ions were effectively removed from source phase through PIM containing 32 wt.% TIOA, 22 wt.% CTA (cellulose triacetate) and 46 wt.% ONPOE (o-nitrophenyl octyl ether) or ONPPE (o-nitrophenyl pentyl ether) into deionized water as the receiving phase. The results indicate that there is a possibility of polymer inclusion membranes application to recover Co(II) and Li(I) from aqueous chloride solutions

Influence of the diluent on the extraction of acetic acid from the prehydrolysis liquor of kraft based dissolving pulp production process by tertiary amine

Different diluents including 1-decanol, 1-octanol and 2-ethyl-1-hexanol and kerosene have been evaluated in extracting acetic acid from the treated prehydrolysis liquor (TPHL) by triisooctylamine (TIOA) or trioctylamine (TOA). Diluent played an important role in recovering acetic acid from the TPHL, thus affecting the extraction equilibrium and extraction efficiency. Polar diluent like 1-decanol, 1-octanol and 2-ethyl-1-hexanol showed better performance than the nonpolar diluent kerosene. The maximum extraction efficiency was 68.79%, which was from 2-ethyl-1-hexanol. The organic solvent was regenerated and extracted HAc was recovered by aqueous sodium hydroxide. The regeneration efficiency can be improved by increasing molar ratio of sodium hydroxide to HAc.

Recovery of acetic acid from pre-hydrolysis liquor of hardwood kraft-based dissolving pulp production process by reactive extraction with triisooctylamine

Acetic acid was one of the main compositions of the pre-hydrolysis liquor (PHL), which was recovered by reactive extraction with triisooctylamine (TIOA) diluted with decanol. Dilution of TIOA played an important role in extracting acetic acid from the PHL. The recovery of acetic acid from the PHL by TIOA was increased from 10.34% to 66.60% with the dilution of TIOA to 20% by decanol at the HAc to TIOA molar ratio of 1, consequently, the equilibrium distribution coefficient KD increased. The effects of time, temperature and pH on the extraction process were also studied. The extraction process was very fast. The acetic acid extraction decreased from 65.13% to 57.34% with the rise of temperature to 50°C from 20°C. A higher pH increased the dissociation of acetic acid, as a result, decreased acetic acid extraction. The hemicelluloses in the PHL were unaffected on the extraction process of acetic acid.

Recovery of HCl from Chloride Leach Solution of Spent HDS Catalyst by Solvent Extraction

Abstract In the present work, amine based extractant and its mixture with cationic and solvating extractants were tested for the extraction of HCl from chloride solution containing Al(III). The chloride feed solution resulted from the leaching of spent HDS (hydro-desulfurization) catalysts. For this purpose, amine extractants, such as TOA (trioctyl amine), Alamine 336 (a mixture of tri-octyl/decyl amine), Alamine 308 (tri-isooctyl amine), and TEHA (tri 2-ethylhexyl amine) were used and the extraction and stripping behavior of HCl was compared. The extracted HCl was easily stripped from loaded TEHA phase, when compared with the other tested tertiary amine system. Solvent extraction reaction of HCl by TEHA was determined from the extraction data. Unlike TOA and Alamine 336, adding cationic extractant to TEHA had negligible effect on the extraction and stripping of HCl. In our experimental ranges, no Al was extracted by amines and pure HCl was recovered. MaCabe- Thiele diagrams for the extraction and stripping of HCl by TEHA were constructed.

Selective extraction of cobalt from strong acidic solutions containing cobalt and nickel through emulsion liquid membrane using TIOA as carrier

The present investigation deals with carrier-facilitated membrane transport of cobalt from strong acidic leach solutions containing cobalt and nickel by emulsion liquid membrane (ELM) using triisooctylamine (TIOA) as carrier. In this work, the zinc plant copper cake was leached with hydrochloric acid solution and main acidic leach solution containing various ions was obtained. After various ions in the acidic leach solution were separated, optimum conditions were determined. The results showed that it is possible to extract 99% of cobalt using ELM from strong acidic leach solutions, containing cobalt and nickel ions, at the optimum conditions.

Synergistic and selective extraction of Cd2+ from acidic solution containing Cd2+, Co2+, Ni2+ by triisooctylamine (TIOA) and tributyl phosphate (TBP)

Selective and synergistic extraction of cadmium from acidic iodine solutions containing Cd2+, Co2+ and Ni2+using solvent extraction (SX) technique is presented in this study. The study has highlighted the importance of main and synergistic extractants composition. The mixtures have evident synergistic effects on Cd2+ with a synergistic enhancement factor of 2.22. The various experimental parameters were studied to determine the optimum extraction and stripping conditions of Cd2+. Under optimum conditions, the maximum extraction efficiency (99.7%) was achieved when using 1.5% (v/v) TIOA and 0.5% (v/v) TBP in dichloromethane within 5min. Extracted Cd2+ was stripped effectively from the organic phase using 2.0mol/L NaOH solution.