Aqueous Phase Ratio Research Articles

Synthesis of DCAP and its effects on extraction separation of light rare earth ions

ABSTRACT A de-tert-butyl calix arene phosphate (DCAP) with a complete elimination of the upper edge and a complete substitution of the lower edge was synthesized by dealkylation and substitution reactions. The chemical structure of DCAP was further characterized by FTIR, mass MS and 1 H NMR. The ability of DCAP to extract light rare earth ions was studied as a function of concentration, aqueous phase pH, phase ratio, and extraction time. The results showed that DCAP had a 4% higher extraction rate of Pr3+ compared to Nd3+ under the same conditions. Preliminary extraction mechanism was also investigated.

Extraction of Rare Earth Elements from Iraqi Phosphate Ore by Using of Tributyl Phosphate

Iraqi phosphate ore deposits have been ascertained to be the second global reserve after Morocco, it has been utilized successfully at Al-Qaim phosphate fertilizers complex in the period 1983-2009. The deposit has valuable content of rare piles of earth and uranium, which is expected to have a good impact on the Iraqi economy if they are recovered from the ore. In the present study, solvent extraction was employed for the extraction of the rare earth elements (REEs), tributyl phosphate (TBP) in kerosene was utilized for extracting ytterbium, yttrium, erbium, and lanthanum from an aqueous solution made via the nitric acid (HNO3) leaching of the concentrate of the Iraqi apatite ore. In the extraction stage, the effect of the concentration of TBP (1, 2, 3, and 3.5) M, contact time (1, 3,5,7,9, and 11) min, and the phase ratio (organic/aqueous) (1/4, 1/3, 1/2, 1/1, 2/1, 3/1, 4/1) were studied. The outcomes manifested, that around 92.9%, 98%, 90.4%, and 98.3% of yttrium, ytterbium, erbium, and lanthanum, respectively were extracted at the best extraction conditions of 3M TBP , 4/1 organic to aqueous phase ratio and 7 min contact time.

Emulsion Liquid Membrane Extraction of Bisphenol A with Three-dimensional Spiral Plate-type Microchannel

The extraction of BPA (Bisphenol A) from aqueous solutions was performed using A set of three-dimensional spiral plate-type microchannel (3D-SPM) by emulsion liquid membrane (ELM). In the continuous extraction experiments, the effect of the flow rate ratio of emulsion to external aqueous phase ratios, Qe/Qa and height of microchannel, H and plate numbers, P, on the BPA extraction was studied. It was found that the less the height of microchannel is, the more extraction efficient it is. By increasing the plate number, the extraction efficiency and the distribution coefficient increase. The optimum performance was investigated by changing the flow rates of Qa and Qe. When using the flow rate ratio Qe/Qa of 7:1 in a 3D-SPM with a plate number of 9 and a height of 100 µm, 97% maximum depletion of BPA was obtained in 7.9 Seconds. These results show that 3D-SPM can intensify the ELM extraction process of BPA, which provides an optional technology for the disposal of BPA.

Carboxymethyl cellulose-based wafer enriched with resveratrol-loaded nanoparticles for enhanced wound healing.

The present study aimed to prepare and investigate the wound healing potential of carboxymethyl cellulose (CMC)-based wafers incorporated with resveratrol (RSV)-loaded cellulose acetate butyrate (CAB) NPs. Accordingly, RSV-CAB NPs were prepared using the solvent evaporation method. The effect of different formulation parameters (polymer content, surfactant concentration, and the volume ratio of aqueous phase to organic phase) on the properties of NPs was investigated using the Box-Behnken design. Then, the optimized NPs were incorporated in wafers comprising CMC combined with hydroxyl propyl methyl cellulose (HPMC) or chitosan. Hydration capacity, porosity, adhesive strength, and hardness of the prepared nanocomposite wafers were examined. Optimized formulation was spherical, showing the particle size, polydispersity index, zeta potential, encapsulation efficiency %, drug loading %, and release efficiency % of 248.5nm, 0.38, - 1.59, 87.58, 25.94, and 67.10, respectively. The CMC-HPMC wafers exhibited higher porosity, hydration capacity, and adhesive performance, as compared with the CMC wafers alone and CMC-chitosan wafers. Wound healing test and histological evaluation in the excisional wounds of the rats showed that the RSV-NPs-wafers were more effective as a healing accelerator, in comparison to wafers without drug or those containing the free RSV. These results demonstrated the potential of the RSV-NPs-wafer in wound healing drug delivery applications. Graphical abstract.

Concentration and Separation of Heavy Rare-Earth Metals at Stripping Stage

The separation and concentration processes of heavy rare-earth metals—yttrium, ytterbium, erbium, and dysprosium—during stripping from the organic phase based on di-2-ethylhexylphosphoric acid (D2EHPA, or DEHPA) solutions were investigated in this work. Optimal conditions providing high separation factors of rare-earth metals (REM) and their extraction degree to the aqueous phase were determined. The usage of sulfuric acid solutions with a concentration of 2–6 mol/L, depending on the type of extracted rare-earth element, was proposed as a stripping agent for rare-earth metals (REM), and the usage of oxalic acid solution was proposed as an iron stripping solution from the organic phase. To increase the REM stripping efficiency, the antagonistic effect of tributyl phosphate in the di-2-ethylhexylphosphoric acid-kerosene-tributyl phosphate system was considered. The possibility of increasing the capacity of the organic solvent by cleaning the organic phase from iron ions using oxalic acid solutions was revealed. The influence of temperature, aqueous and organic phase ratio, stirring rate, and re-extractant concentration on the distribution and separation factors of adjacent heavy rare-earth-metal (HREM) pairs during the re-extraction process were determined. A schematic diagram of the laboratory-tested separation process of heavy rare-earth metals into individual components with the obtaining of yttrium and ytterbium concentrates containing more than 99% of the target components was proposed.

Leaching and purification of indium from waste liquid crystal display panel after hydrothermal pretreatment: Optimum conditions determination and kinetic analysis

Indium is one of the components with great recycling value in waste LCDs. Degradation of organic materials and the remain of indium in the solid phase can be simultaneously achieved by hydrothermal pretreatment via parameter regulation. Indium was transferred from the solid phase to the liquid phase by using sulfuric acid after hydrothermal pretreatment. Di-(2-ethylhexyl) phosphoric acid diluted by sulfonated kerosene and hydrochloric acid were used as extractant and stripping agent respectively to purify and concentrate indium from acidic leaching solution. The results indicated that the leaching yield of indium reached 100% under the optimal condition of reaction time of 40 min, reaction temperature of 70–80 °C, acid concentration of 0.5 M and solid-liquid (S/L) ratio of 1:2 g/mL. Given conditions of extraction time of 3 min at the organic phase to aqueous phase (O/A) ratio of 1:10 by 20% D2EHPA and stripping time of 10 min at the (O/A) ratio of 10:1 by 4 M HCl, the recovery efficiency of indium reached 97.25%. In addition, acid leaching process did not change the surface topography and molecular structure of glass substrate and had no negative effect on subsequent recycling of glass. The kinetic equation of leaching yield and reaction time at the temperature of 80 °C is 1 − (1 − y)1/3 = 0.0215 t. The reaction activation energy of metal indium leaching process is 50.64 kJ/mol.

Water decolorization using waste cooking oil: An optimized green emulsion liquid membrane by RSM

The current study reduces the issues caused by petroleum-based organic solvents, which commonly employed in emulsion liquid membrane (ELM) process. The waste cooking oil as a low-cost easily available nontoxic organic solvent was used in a green ELM (GELM) process without complicated pretreatment stages. Methyl violet 2B (MV) dye was chosen as the sample cationic dye for the study of the ability of waste vegetable oil in water decolorization. The proposed GELM included Span 80 as the surfactant, hydrochloric acid as the internal phase, and waste vegetable oil as the diluent. Initially, Plackett–Burman screening design was employed for the determination of important influencing parameters in dye removal by GELM. Afterward, to achieve the optimal process conditions, Box–Behnken design was used. The optimized factors were Span 80 concentration of 3 wt%, internal phase concentration of 1.43 M, MV concentration of 24.59 mg/L, and organic phase to aqueous phase ratio of 2.07. The maximum achieved MV extraction efficiency was found to be 99.1% under the optimized process conditions and without utilizing the carrier agent. Also, the membrane might be recovered for more than seven times.

Parametric studies of Cu(II) ion extraction into palm kernel fatty acid distillate as a green organic solvent

Palm kernel fatty acid distillate (PKFAD), a processing residue from palm kernel oil refineries with a high amount of free fatty acids (80–90 wt%), was used as a green organic solvent for sustainable extraction of Cu(II) ions from aqueous solutions in this work. The effects of various extraction parameters (equilibrium pH (pHeq), organic to aqueous phase (O:A) ratio, inert salt concentration, and temperature) on Cu(II) ion extraction by PKFAD were investigated and the optimum conditions were determined. The stripping of Cu(II) ions from Cu(II)-loaded PKFAD, as well as the loading capacity and reusability of PKFAD, was also studied. Results revealed that the highest Cu(II) ion extraction of 98% was achieved at pHeq of 4.7, O:A ratio of 0.5:1, inert salt concentration of 200 mM, and temperature of 25 °C, while a high Cu(II) ion stripping of 94% from Cu(II)-loaded PKFAD was accomplished with 1 M formic acid at O:A ratio of 1:1. Under the optimum extraction and stripping conditions, the estimated loading capacity and reusability of PKFAD were 7520 mg/L and 15 cycles minimum, respectively. Therefore, PKFAD is a potential green organic solvent for Cu(II) ions extraction from aqueous solutions.

Separation of titanium from vanadium and iron in leach solutions of vanadium slag by solvent extraction with trioctyl tertiary amine (N235)

The separation of titanium (Ti) (IV) in acidic leach solutions of vanadium slag by solvent extraction with trioctyl tertiary amine (N235) is proposed. Because the leach solutions contain a lot of vanadium (V) and iron (Fe) impurities, the effects of various conditions on the separation of Ti, V, and Fe were investigated. Then, the extraction mechanism and thermodynamics of the process were discussed. Upon using 35% (v/v) N235 and 65% (v/v) sulfonated kerosene as the extractant, over 82% Ti was extracted at a 2:1 organic to aqueous phase ratio (4 min at 298.15 K in a single-stage contract) with only 5% V and 10% Fe co-extracted. After the three-stage extraction, over 97% Ti, 7% V, and 18% Fe were extracted. By washing with 1.25 mol/L ammonium sulfate, most of the V and Fe impurities were removed with an insignificant amount of Ti wasted. Upon stripping with 1.0 mol/L ammonia at a 1:1 organic to aqueous phase ratio, approximately 90% Ti was recovered from the purified organic liquor. Other impurity elements such as Mn, Al, Mg, Ca and Si have little effect on the Ti separation. The possible composition of Ti-containing extract may be (R3NH)2·TiO3, and Fourier transform infrared spectroscopy (FT-IR) analysis confirmed that the characteristic peaks representing NTiO and TiO were in the extracted compound. The mechanism of the extraction included the association of R3NH+ from N235 with TiO32− from the acidic leach solutions. Furthermore, thermodynamic calculations showed that Ti separation from the leach solutions of vanadium slag using N235 is an exothermic, irreversible, and possible reaction at 298.15–338.15 K.

A robust systematic design: Optimization and preparation of polymeric nanoparticles of PLGA for docetaxel intravenous delivery.

Poly (lactide-co-glycolide) (PLGA) is a biocompatible, biodegradable, and non-toxic polymer used in a variety of biomedical and pharmaceutical applications. Polymeric nanoparticles prepared from PLGA have been extensively used as delivery vehicles of various chemotherapeutic agents. The variability of PLGA polymer and nanoparticle fabrication process potentially results in variability of particle characteristics. Nanoparticle characteristics determine nanoparticles' performance when used as drug delivery systems. Having control on nanoparticle's characteristics grants control over the fate of nanoparticles and the associated drug. Here, L16 Taguchi experimental design was used to evaluate the effect of polymer characteristics and fabrication variables on PLGA nanoparticles. The design was used to determine an optimized preparation condition for PLGA nanoparticles as an intravenous delivery system for docetaxel. An emulsification-solvent-evaporation method was used to fabricate nanoparticles. Docetaxel concentration, organic phase:aqueous phase ratio, polymer molecular weight, polymer terminus, lactide:glycolide ratio, and Poly(vinyl alcohol)(PVA) concentration were selected as main determinants. First two factors were evaluated at 4 levels and the rest at 2 levels. Particle-important characteristics including size, polydispersity index (PDI), surface charge (zeta potential), and docetaxel loading-efficiency were determined. Factors affecting nanoparticle characteristics were ranked according to level of effectiveness. Factors that affected nanoparticle properties with statistical significance were identified. Models to predict nanoparticle characteristics were built. An optimized fabrication method was identified and used to prepare PLGA nanoparticles for docetaxel delivery.

Removal of Fluorine from Wet-Process Phosphoric Acid Using a Solvent Extraction Technique with Tributyl Phosphate and Silicon Oil.

The deep removal of fluorine from wet-process phosphoric acid is currently a very serious issue. In this paper, an efficient liquid–liquid separation method based on a bubble membrane was developed to solve this problem. Tributyl phosphate (TBP) and silicon oil (SIO) were used as the organic phase. The effects of the component proportion in the organic phase (TBP/SIO v/v), organic to aqueous phase ratio (O/A), pH, temperature, and reaction time on the extraction ratio were investigated. The extraction ratio of fluorine was 98.4% when using only one stage with the following conditions: 90 °C, pH −0.46, volume ratio (TBP/SIO v/v) of 7:3, phase ratio (O/A) of 1:5, stirring speed of 200 rpm, and reaction time of 50 min. Fourier-transform infrared spectroscopy and inverted fluorescence microscopy were used to investigate the reaction mechanism and reaction kinetics. In addition, the scrubbing and stripping process was investigated. When a 2 mol/L sodium hydroxide solution ([NaOH]) was used as the stripping agent with a phase ratio (O/A) of 1:10, a stirring speed of 200 rpm, and a reaction time of 30 min, a maximum stripping ratio of 90.1% was obtained.

Regeneration and characterization of LiNi0.8Co0.15Al0.05O2 cathode material from spent power lithium-ion batteries

The use and scrap of lithium ion batteries, especially power lithium ion batteries in China, are increasing every year. Regeneration of spent battery materials is not only important for environmental protection and resource saving, but also for the production of high value-added materials. In this research, spent power lithium-ion battery cathode material LiNi1-xCoxO2 was acid-leached and a polymetallic leaching solution containing Li, Ni, Co, Al and Cu was obtained. Cu was extracted from the leachate by using CP-150 (2-hydroxy-5-nonyl salicylaldehyde oxime). The optimal conditions were found to be organic: aqueous phase ratio (O/A) = 2:1, extraction agent concentration of 30%, and pH = 3. The precursor was prepared by coprecipitation of the leachate after Cu removal. Then, cathode material of lithium nickel cobalt aluminate LiNi0.8Co0.15Al0.05O2 was synthesized under the optimal conditions of n (precursor): n (lithium carbonate) = 1:1.1, calcination temperature of 800 °C for 15 h. The regenerated LiNi0.8Co0.15Al0.05O2 product prepared under the optimized conditions was in a pure phase with a layered structure and a smooth surface morphology. The first charge specific capacity was 248.7 mAh/g, and the discharge specific capacity was 162 mAh/g. The interfacial impedance was 119 Ω. The 50th-cycle discharge specific capacity was 149.1 mAh/g, and the capacity retention rate was high as 92%. Therefore, the regenerated cathode material exhibited good performance.

Extraction and Separation of Zirconium Using 1-Octanol

A selective extraction and separation of zirconium by solvent extraction with 1-octanol is proposed. The process is based on the dissolution of the metal basic carbonates in hydrochloric acid in the presence of potassium fluoride, using 1-octanol as extractant. The effect of several process parameters, including hydrochloric acid and potassium fluoride concentrations, reaction time, and phase ratio between the aqueous and the organic phase was investigated. Zirconium is enriched in the organic phase. The best extraction and separation results were obtained with the basic carbonate dissolved in 10% hydrochloric acid and 1.5 M potassium fluoride. The optimum reaction time was 15 min with an organic to aqueous phase ratio of 2:1. Based on the selectivity of zirconium over hafnium in the organic phase, a McCabe-Thiele diagram was constructed. A near complete stripping of zirconium from the organic phase was achieved using a 3 M sulphuric acid solution. Additional studies are required in order to determine the reaction mechanism and the chemical speciation of the current investigation.

Effect of Key Parameters on Jacalin Extraction from Aqueous Phase into Anionic Reverse Micelles

This study demonstrates the extraction of jacalin from crude extract of jackfruit seeds using anionic surfactant based reverse micellar system, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in isooctane. Effects of various parameters, such as, NaCl concentration (0.05 – 1 M), pH of aqueous phase (pH 4 – 10), AOT concentration (5 – 150 mM), contact time (5 – 30 min) and phase volume ratio (0.5-5) on the transfer efficiency of jacalin was evaluated by changing one factor at a time (OFAT) while keeping the other parameters constant. A maximum of 83% of protein transfer was achieved after equal volume of organic and aqueous phase was stirred for 20 min using 20 mM AOT at pH 5 aqueous phase containing 0.1 M NaCl. The findings demonstrated AOT reverse micellar system as a promising and effective method to extract and purify jacalin from crude protein mixture.

Design and optimization of PEGylated nanoparticles intended for Berberine Chloride delivery

The pre-formulative screening for polymeric nanoparticles (NPs) manufacture is a very long and laborious process. It is essential however for the selection of the best experimental conditions. The chemical and physical properties of NPs can be affected by different factors and variables during their preparation and thus, the aim of this work is to study the influence of the polymer concentration and the organic to aqueous phase ratio on PLGA-PEG NPs by using a D-optimal Response Surface Methodology (RSM) design. A total of nine formulations were prepared using the nanoprecipitation method, purified and characterized for their size, polydispersity index (PDI) and zeta potential. All formulations were subjected to stability studies after storage over six months under refrigeration. Prediction of the optimal nanosystem was performed using the desirability function targeting the reduction of NPs size and PDI. The optimized NPs formulation (F-1) showed similar theoretical and experimental values, confirming the predictive ability of the mathematical model. The formulation F-1 loaded with Berberine Chloride showed appropriate technological properties for potential intranasal or systemic administration. Our results conclusively demonstrated that RSM is a useful and efficient tool to design new nanoformulation with the least number of experiments.

Recovery of lithium from alkaline brine by solvent extraction with functionalized ionic liquid

Lithium recovery from alkaline brine was carried out by solvent extraction (SX) using a hydroxyl-functionalized ionic liquid, 1-hydroxyethyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)imide ([OHEMIM][NTf2]) and a neutral ligand, trialkyl phosphine oxide (Cyanex923) as the extractants. Effect of extraction parameters, i.e. concentration of ionic liquid, extraction time, pH value of aqueous phase, phase ratio and mole ratio of sodium to lithium, on lithium extraction efficiency have been studied. Under the optimal parameters, over 93% of lithium was extracted in one single run. The extraction mechanism of lithium was investigated by the combination method of experiment and UV–visible spectroscopic characterization, and it was found that the ion exchange predominated during the extraction process. The extraction complex was determined by a slope analysis method, indicating that Cyanex923, Li+ and [NTf2]- formed a 2:1:1 complex. The thermodynamic study indicated that lithium extraction reaction was spontaneous. Based on the above results, [OHEMIM][NTf2]-Cyanex923 extraction system showed a promising application in the recovery of lithium from alkaline brine.

Development and Optimization of Alendronate Sodium Loaded PLGA Nanoparticles by Central Composite Design

Alendronate sodium (AS) which supresses the activity of osteoclastic cells and leads to the inhibition of bone resorption, is one of the most clinically preferred drug for the treatment of osteoporosis. The purpose of this research is to develop an optimization method for AS loaded poly(lactide-co-glycolide) (PLGA) nanoparticle formulation which is prepared by nanoprecipitation method and is intended for local application to provide enhanced guided bone regeneration. Nanoparticle formulation parameters including AS content, polymer/surfactant ratio and organic to aqueous phase ratio were optimized to evaluate their effects on particle size, polydispersity index (PDI), zeta potential and entrapment efficiency by using central composite experimental design (CCD). Morphology of nanoparticles was visualized with transmission electron microscopy (TEM) and interaction between nanoparticle components was analyzed by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The developed quadratic model showed high correlation (R2>0.89) between predicted response and evaluated parameters. Spherical nanoparticles with mean particle size of 34.68% were produced with the optimized nanoparticle preparation method. The optimization of AS encapsulating PLGA nanoparticles by utilizing CCD method, allowed us to prepare the nanoparticle formulation with optimum properties with less experiments. Consequently, this optimized model can be applied to predict the characteristics of nanoparticles prepared with nanoprecipitation method by using PLGA polymer.

Parametric optimization of green synergistic reactive extraction of lactic acid using trioctylamine, Aliquat336, and butan-2-ol in sunflower oil by response surface methodology

A novel green synergistic reactive extraction technique for the removal of lactic acid (LA) from aqueous solution was explored. Response surface methodology (RSM) was applied to optimize the process variables for LA synergistic reactive extraction using a mixture of trioctylamine and Aliquat336 as extractants. During this present investigation, 2-butanol and sunflower oil were used as organic and green diluent. Systematic investigation has been carried out to obtain the optimum process conditions viz. initial LA concentration, pH of aqueous solution, extractant ratio, extractant concentration, solvent ratio, phase ratio, temperature, stirring speed, and contact time for maximizing the LA distribution coefficient (KD) and extraction efficiency (%, η). The highest experimentally achievable LA distribution coefficient (KD) and extraction efficiency (%) at optimized process conditions were found to be in close agreement with those predicted by numerical optimization using RSM. Thus, the results of present finding have been shown a great ability of sunflower oil as an economic and environmentally friendly green solvent for LA extraction.

Evaluation the Effects of Ultrasonic Parameters on Simultaneously Extraction and Size Reduction of Lycopene from Tomato Processing Waste

Lycopene was simultaneously extracted from tomato processing waste and size reduced into nano-ranges from 36 to 150 nm, via ultrasonic assisted nanoprecipitation technique. The effects of main processing parameters namely, organic to aqueous phase ratio, ultrasonic amplitude and time were evaluated on mean particle size, polydispersity (PDI) and lycopene content of produced nanodispersions, using response surface method based on central composite design. All studied parameters affected the selected responses significantly (p-value 0.9). The most desirable lycopene nanodispersions with mean particle size of 66.3 nm, PDI of 0.245 and lycopene content of 52 mg/g waste, were produced at organic to aqueous phase ratio of 0.5, and ultrasonication for 20 min at amplitude of 70%. The resulted insignificant differences between experimental and predicted data, certified the suitability of suggested response surface models.

PH-responsive Astragalus polysaccharides-loaded poly(lactic-co-glycolic acid) nanoparticles and their in vitro immunogenicity

Astragalus polysaccharides (APS) have long been well known as immune boosters, but have not been fully exploited in clinical settings. Here, poly(lactic-co-glycolic acid) (PLGA) was used to form a nanocarrier for APS to enhance its bioavailability. The aim was to improve the immunoadjuvanticity of conventional APS-loaded PLGA-based nanoparticles (NPs), referred to as APSPs, and to optimize the synthesis parameters to maximize the encapsulation efficiency (EE). As slow drug release can cause insufficient immune responses, ammonium bicarbonate was used to produce pH-responsive APSPs. The optimum parameters for maximizing EE (mean maximum experimental EE: 65.23 ± 0.51%) were an oil phase (O)/internal aqueous phase (W1) ratio of 7:1, an external aqueous phase (W2)/preliminary emulsion (PE) ratio of 5:1, and a Pluronic F-68 concentration of 1.1%. Moreover, the pH-responsive APSPs had low cytotoxicity and significantly enhanced mice splenic lymphocyte proliferation. The increased T-cell CD4+/CD8+ ratio after pH-responsive APSP treatment of mice splenic lymphocytes compared with free APS, blank PLGA NP, and conventional APSP treatment demonstrated its excellent immunoadjuvanticity. This study provides abundant evidence that these novel PLGA-based pH-responsive NPs enhanced the immunoadjuvanticity of APS. Furthermore, pH-responsive APSPs synthesized using the optimum parameters exhibited long-term stability in normal storage conditions, suggesting suitability for clinical application.