Multistage Countercurrent Extraction Research Articles

A new multistage counter current extraction method of removing fluoride from defatted Antarctic krill powder

This study aims to find an efficient acid extraction method to remove fluoride from defatted krill powder. Considering the effects of acid species, concentration, temperature, extraction time, solvent volume on the defluoridation efficiency, and final product yield, a new multistage counter current extraction method was developed. The optimum reaction condition was obtained by adding 10 ml of 0.3 M HCl to 1 g defatted krill powder and extracting for four stages, each stage was lasting for 60 min. After this process, fluoride content per dry weight of the final product was remarkably reduced to <5 mg/kg, defluoridation efficiency was 99.70%, and water consumption was minimized. Fourier transform infrared spectroscopy also indicated a decrease in the amount of fluorine, and basic chemical composition measurement indicated krill protein was not damaged during this process. Therefore, these results could be used as theoretical guidance for removing fluoride in practical application. Practical applications Defatted Antarctic krill powder is a cheap by-product after krill oil extraction, but it contains both high-quality protein and high concentration of fluoride. The toxicity of fluoride in krill powder makes it not be allowed as food resource. So, a new counter current extraction method was developed to defluorinate from defatted krill powder, which was an easy and cheap process, but high defluoridation efficiency with low water consumption. It has been successfully applied to the food pilot base, and it would help to obtain the safe defatted Antarctic krill powder in krill industry.

The Effect of Continuous Multistage Countercurrent Extraction (CMCE) Propolis Extract Administration on Leydig, and Sertoli Cells Counts, and Sperm Quality Induced With Monosodium Glutamate (MSG) (An experimental study on male Wistar rat induced by monosodium glutamate)

INTRODUCTION: ROS is the most common cause of male infertility. Monosodium glutamate (MSG) is a compound which produces ROS and decreases FSH and LH levels. Continuous Multistage Countercurrent Extraction (CMCE) propolis extract as an antioxidant is evidently capable of reducing ROS concentration. OBJECTIVE: this research aims at evaluating the effect of CMCE propolis extract administration on Leydig cells and Sertoli cells counts and sperm quality of MSG-induced male wistar rats. METHODS: employing the Post Test Only Control Group Design, 18 rats were divided into 3 groups: control group, treated only with MSG (MS-G), and treatment groups, respectively treated with CMCE propolis extract at doses 8.3mg/day (CM8-G) and 10.8mg/day (CM10-G). CMCE propolis extract was given orally for 21 days. At the end of treatment, sperm and testis were taken to evaluate the Leydig cells and Sertoli cells counts and sperm quality. The sperm obtained from epididymis was analyzed using the WHO standards, while Leydig cells and Sertoli cells were counted from preparation using the HE stain method. RESULTS: the Post Hoc analysis result shows that the Leydig and Sertoli cells counts and sperm quality of CM8-G and CM10-G are significantly higher than those of MS-G, p&lt;0.05. The Leydig cells and Sertoli cells counts and sperm quality of CM10-G are significantly higher than those of CM8-G, p&gt;&lt;0.05. CONCLUSION: CMCE propolis extract administration evidently increases the Leydig cells and Sertoli cells counts and sperm quality from the perspective of the count, motility and morphology of spermatozoa of MSG-induced male wistar rats.&gt;&lt;0.05 CONCLUSION: CMCE propolis extract administration evidently increases the Leydig cells and Sertoli cells counts and sperm quality from the perspective of the count, motility and morphology of spermatozoa of MSG-induced male wistar rats.

Modeling of counter-current multistage extraction of Moringa oleifera leaves using a mechanistic model

Antioxidant extracts obtained from natural products is highly relevant for the food, chemical and pharmaceutical industries. Moringa oleifera leaves contain significant levels of phenolic compounds with antiradical activity. Counter-current multistage extraction (CME) has been developed for the extraction of M. oleifera leaves. A mixture of ethanol:water 80:20 (w/w) was used as extraction solvent. The effects of extraction stage numbers, temperature, extraction time and solvent to sample ratio on the extraction yield were investigated. Process conditions of CME were optimized using a mechanistic model conceptualized by our work group. Under optimum process conditions (three stages, 120min extracting time for every stage, 55°C temperature and 0.03g/g solvent to sample ratio) CME process offers high extraction yield and considerable savings in time, energy and solvent consumption.

Reactive Zinc Extraction with D2EHPA in a Kühni Miniplant Column

AbstractReactive extraction of Zn2+ with di‐(2‐ethylhexyl) phosphoric acid (D2EHPA) was examined in a multistage countercurrent extraction column of type Kühni. Hydrodynamics and mass transfer for the reactive European Federation of Chemical Engineering (EFCE) test system were comprehensively experimentally investigated in a DN32 Kühni miniplant column. The experiments demonstrate that the column hydrodynamics and mass transfer performance markedly depend on throughputs, phase ratio, energy input as well as on the component concentrations. Using a simple equilibrium stage model, it was found that two to four stages per meter can be reached in the miniplant extractor. The system physical properties (density, viscosity, interfacial tension) of the reactive test system change rapidly due to mass transfer, which is considered by appropriate correlations.

Complete removal of trace vanadium from ammonium tungstate solutions by solvent extraction

The complete removal of trace vanadium from ammonium tungstate solutions by solvent extraction using a quaternary ammonium salt with bicarbonate type as extractant was investigated. The effects of organic composition, equilibrium pH and A/O ratio on the extraction and stripping were studied. The metal extraction and stripping isotherms were plotted and the simulation multi-stage counter current extraction and stripping tests were conducted. The results showed that the vanadium can be more easily extracted over tungsten from ammonium tungstate solutions, dropping vanadium to 0.004 g/L with tungsten loss below 5% after six-stage counter current extraction with an organic solvent consisting of 1% (v/v) Aliquat336 and 5% (ν/ν) 2-octanol and a feed containing 100.0 g/L W(VI) and 0.42 g/L V(V) with an A/O ratio of 1/1.25 at pH 8.74 and 25 °C for 10 min. The extracted vanadium(V) species of V2W4O194− in loaded organic solution was identified by the combination of thermodynamic analysis and saturation methods, and FTIR spectral analysis. The vanadium(V) in loaded organic was easily stripped and enriched using 2 mol/L NaOH solution with an A/O ratio of 1/15 in a four-stage counter current stripping, and the stripped organic could also be recycled to extraction after regeneration with ammonium bicarbonate solution.

Simultaneous separation and concentration of polyphenols from pomegranate industrial waste by multistage counter-current system; comparing with ultrafiltration concentration

Abstract Pomegranate industrial waste (PIW) could be an attractive source for the economic recovery of natural antioxidant (polyphenols) with well-known health benefits. Industrial processing of above 0.35 MMT pomegranates produces considerable amounts of PIW annually in Iran at both a high cost and risk to the environment. Multi-stage countercurrent extraction (MSCE) has been used to produce high concentrated polyphenolic extract from PIW for commercial purposes. In comparison with the single pot extraction, the MSCE was comprised advantages of much lower extraction solvent (8 ml/g versus 30 ml/g) and the extraction temperature (40 °C versus 65 °C) leading to reduce energy consumption, and the prevention of bioactive substances being degraded. Superiority of the MSCE process against two steps processes, comprising single pot extraction and ultrafiltration (UF) concentration was also demonstrated. For the final product, hydrolysable tannins (HT: 59.14 mg tannic acid equivalent/g), total flavonoids (TF: 22.59 mg rutin equivalent/g), radical scavenging activity (DPPH IC50: 12.52 mg/L extract) and ferric reducing antioxidant power (FRAP: 730.2 µM Fe (II)/g waste), were also quantified. A custom made solid phase extraction set-up was used for the separation and purification of HT as the major constituents of TPC (about 50%), which were further characterized and quantified by HPLC analysis.

Recovery of boric acid from salt lake brines by solvent extraction with 2-butyl-1-n-octanol

A systematic investigation was conducted on the extraction of boric acid from salt lake brine using 2-butyl-1-n-octanol dissolved in sulfonated kerosene. The extraction parameters, including the concentration of extractant, phase ratio and pH value of the brine, were optimized. The salting-out effects of the extraction process were investigated in the presence of AlCl3, MgCl2 and NaCl, and an empirical equation was subsequently proposed. The positive salting-out effects were observed on the extraction of boric acid in the order of AlCl3 > MgCl2 > NaCl. Thermodynamic modeling results indicate that the extraction process is exothermic. To evaluate the feasibility of the process, a multi-stage countercurrent extraction and stripping process was performed under the optimized operating conditions. The results showed an overall boric acid extraction efficiency of 99.35% and a stripping efficiency of 99.63%, and the overall boric acid recovery and the purity of the stripping solution both exceeded 98%. The results of this study reveal a potential industrial application of the boric acid extraction process.

Extraction of rubidium from respirable sintering dust

Respirable sintering dust was an abundant and hazardous waste arrested by electrostatic precipitators from iron and steel industry. In this study, this waste was first found to contain 0.3% Rb, existing in the form of chloride and making it a promising Rb extracting material. Meanwhile, 95.24% of Rb and 93.43% of K in it can be easily recovered by water leaching (S/L=1:5), resulting in a solution of 740mg/L Rb and 33.85g/L K. Then this leachate was extracted with 4-tert-butyl-2-(α-methylbenzyl) phenol (t-BAMBP) in sulphonated kerosene to separate Rb from K after purification. The optimized solvent extraction conditions were 1.0mol/L t-BAMBP, phase ratio of 3:1, 1.2mol/L alkalinity in aqueous. Moreover, the organic phase was treated with deionized water (O/A=5:1) for scrubbing and 1.2mol/L HCl (O/A=5:1) for stripping. Under optimal conditions, a single Rb extraction and back-extraction efficiencies were 91.80% and 89.93%, respectively. Finally, a RbCl with 99.5% purity and a total Rb extraction rate of 58.26% were achieved by a multistage continuous countercurrent extraction. These results did not only indicate that respirable sintering dust is a new tremendous potential Rb source but also provide a promising way to utilize Rb from this dust.

Reprocessing Th-based spent fuels with di-1-methyl heptyl methyl phosphonate using centrifugal extractors

In this paper, a reprocessing Th-based spent fuels process using di-1-methyl heptyl methyl phosphonate (DMHMP) as extractant was proposed and tested by multistage countercurrent extraction using batch simulation and centrifugal extractors. The analysis results of process samples show that the recovery of Th and U in 1A (co-extraction of Th and U), 1B (separation of Th from U) and 1C (stripping of U from organic to aqueous phase) section was more than 99.8% and 99.9%, respectively. The separation factor of Th from U and U from Th in 1B section was 5.9×103 and 7.1×103, respectively. Compared with Thorex process using TBP as extractant, the process could be operated under lower acidity and flow ratio of O:A due to the strong extraction ability of DMHMP. Thus, DMHMP would be a promising alternative extractant for Th-based spent fuels process.

Development of Phenols Recovery process from coal gasification wastewater with mesityl oxide as a novel extractant

The extractant has a great influence on the performance and economy of the Phenols Recovery processes for treating coal-gasification wastewater. Meanwhile, computer-aided screening techniques have been applied to discern candidate solvents from the molecular perspective. In this paper, mesityl oxide, as a novel extractant, is found with high phenols removal efficiency through quantum chemical calculations. To confirm that, the removal performance with three different solvents (diisopropyl ether (DIPE), methyl isobutyl ketone (MIBK) and mesityl oxide) are investigated and compared via multi-stage counter-current extraction experiments. The experimental results identified that the performance using mesityl oxide as solvent is better than that using DIPE and MIBK. The total phenols concentration can be reduced from more than 5000 mg/L to less than 250 mg/L. Then, Phenols Recovery process using mesityl oxide as solvent is developed and conceptual designed. In view of the better performance and lower cost, mesityl oxide is a very promising extractant for the removal of phenols.

The recovery of uranium from irradiated thorium by extraction with di-1-methyl heptyl methylphosphonate (DMHMP)/ n -dodecane

Abstract The process using DMHMP as extractant for the recovery of uranium from irradiated thorium was proposed. Firstly, the process parameters, including concentration of DMHMP, concentratation of HNO3 in feed, scrub and stripping solution, and phase ratio, were systematically optimized by batch extraction experiment. Then, a batch multistage countercurrent extraction simulation experiment was used to verify and test the process. Finally, the irradiation stability of DMHMP was assessed and compared with TBP. The results indicate that DMHMP is a potential candidate for the separation of U(VI) from bulk Th(IV). Furthermore, the complexes of U(VI) and Th(IV) with DMHMP were also demonstrated.

Recovery of Co(II) and Ni(II) from chloride leach solution of nickel laterite ore by solvent extraction with a mixture of Cyanex 301 and TBP

Cyanex 301 can extract both Ni(II) and Co(II) from the leach solution of nickel laterite ore. About 10mol/L HCl solution is needed to strip Ni(II) from the loaded Cyanex 301. To overcome this difficulty, a mixture of Cyanex 301 with TBP was employed to develop a process for the recovery of Co(II) and Ni(II) from the laterite leach liquor. It was found that this mixture showed synergism on the extraction of Ni(II) and significant improvement in Ni(II) stripping was obtained. A developed process was proposed, in which Co(II) and Ni(II) were selectively extracted by this mixture over other elements, and then stripped with 3 and 7mol/L HCl solutions, respectively. A comparison of single Cyanex 301 and Cyanex 301+TBP process was made and discussed in detail. The essential advantages of single Cyanex 301 process were retained in this mixture process, while the main drawback in Ni(II) stripping was improved. Batch-type experiments were conducted to simulate multi-stage counter-current extraction and stripping, indicating that Ni(II) of 99.96% purity was obtained with a recovery percentage of 92.7%.

Removal of cesium by countercurrent solvent extraction with a calix[4]crown derivative

ABSTRACTA macrocyclic 1,3-di(1-dodecyloxy)-2,4-crown-6-calix[4]arene (DodCalix[4]C6) was synthesized and characterized. The extraction of Cs(I) and more than 10 typical metals with DodCalix[4]C6/octanol in HNO3 medium was investigated. DodCalix[4]C6 exhibited strong extraction ability and high selectivity for Cs(I) over others except for Rb(I). The optimum acidity in Cs(I) extraction was 3.0 M HNO3. The Cs(I) separation from a simulated highly active liquid waste by five-stage countercurrent extraction was performed. The extraction efficiency of Cs(I) for five-stage extraction was greater than 99%. The effective partitioning of Cs(I) by DodCalix[4]C6/octanol through multistage countercurrent extraction was achieved.

Synergistic solvent extraction of vanadium from leaching solution of stone coal using D2EHPA and PC88A

Abstract New extractant and an extractant system are attractive for liquid-liquid extraction. To improve the extraction efficiency and selectivity, the binary extractant system consisting of bis-2-ethylhexyl phosphoric acid (D2EHPA) and 2-ethylhexylphosphonic mono-2-ethylhexyl (PC88A) was explored to separate vanadium (V) via synergism from multi-element sulphuric acid leaching solution in this study. The optimal proportion and concentration of extractant was investigated and results demonstrated that the maximum synergistic co-efficient was 1.52 by adjusting the volume ratio to 14:6 (D2EHPA/PC88A) when the extractant concentration was 20% (v/v). Next, the selectivity of the mixture was investigated at different pH values and contact time, which demonstrated better separation of vanadium from primary impurities compared with extraction by D2EHPA or PC88A alone. Furthermore, the Fourier Transform Infrared (FT-IR) spectra were employed to analyse the mechanism of extraction. The results suggested that the cation exchange (P OH bands) and coordination reaction (P O bands) contribute to vanadium extraction, and the structure of extracted complex was proposed. The formation of a dimer between D2EHPA and PC88A was demonstrated. Finally, after multi-stage counter-current extraction and stripping, V2O5 product with a high purity of 99.07% was obtained by oxidation, precipitation and calcination.

Separation of V(V) and Cr(VI) in leaching solution using annular centrifugal contactors

The effective V(V) and Cr(VI) separation is very difficult due to their similarity in physiochemical properties. In this research, almost completely separation of V(V) and Cr(VI) with primary amine N1923 was firstly demonstrated by employing multistage countercurrent extraction (MCE) with annular centrifugal contactors (ACCs). The optimum operation conditions of single-stage extraction with ACC were determined by systematic experiments, and best conditions of the rotor speed, the flow rate and the flow ratio of organic phase to aqueous phase were obtained. The loaded-organic phase can be reused for extraction process after stripping with ammonia/sodium hydroxide. Vanadium, in the leaching/aqueous solution with the initial pH of 6.1, was reached to extraction equilibrium by three-stage countercurrent extraction with ACCs. V(V) and Cr(VI) were separated through 21 stages of countercurrent extraction with ACCs. 95.1% of vanadium and almost none of chromium were extracted, with the separation factor approaching infinity. Through the mechanism of hydrogen bond association and different species of two metals in the leaching/aqueous solution, an in-depth analysis to correlate the results obtained and the chemical reactions with ACCs has been made in order to establish a firm conclusion with aim of the guidance in industrial application.

Wet process of phosphoric acid purification by solvent extraction using tri-n-butyl phosphate and cyclohexanol mixtures

Solvent extraction is an efficient, economical and widely-used technology for the purification of wet process phosphoric acid (WPA). This present work focused on the development of a solvent extraction system, TC, representing tri-n-butyl phosphate (TBP) and cyclohexanol mixtures. The equilibrium phase diagram of the system H3PO4?H2O?TC at 298.2 K and atmospheric pressure was obtained. The effects of extraction time, phosphoric acid concentration, extractant concentration, temperature and phase volume ratio on extraction efficiency were studied. The extracted complexes were estimated to be 1.8H3PO4 2TC. The extraction process of H3PO4 was exothermic and the enthalpy change, ?H, was obtained. The solvent mixtures had a high efficiency for phosphoric acid purification via multi-stage counter-current extraction from the industrial WPA in a reciprocating plate extraction column with an H3PO4 extraction yield of 85.08 % at 313.2 K. The stability, extraction efficiency and recycling capability of TC for H3PO4 extraction were also estimated.

Solvent Extraction of Scandium from the Waste Solution of TiO2 Production Process

Extraction and stripping properties of Sc3+ were investigated by using a mixed extractant of Versatic Acid 10 (VA10) and Tri-n-butyl phosphate (TBP). The effect of adding TBP to VA10 was considered by analyzing the binding state of VA10 and TBP by FT-IR. Solvent extraction of scandium from an aqueous solution of Sc3+–Ti4+–Zr4+, which simulated waste water from the titanium oxide manufacturing process, the Bayers process and others, was performed, and the separation factor of Sc3+ over Ti4+ and Zr4+ was investigated. To clarify the operating conditions of a countercurrent multistage process for Sc3+, McCabe–Thiele analysis was applied to the extraction isotherm and stripping isotherm of Sc3+. The extraction pH of Sc3+ was found to shift to higher pH, and Sc3+ was stripped at a lower concentration of H2SO4 by adding TBP to VA10. Addition of TBP to VA10 suppresses the extraction of Sc3+ and promotes the stripping of Sc3+. IR spectra of the organic phase suggested that the dimeric portion of VA10 formed hydrogen bonds with TBP. The extractions of Sc3+, Ti4+ and Zr4+ were 77, 3 and 8%, respectively. The separation factors of these metal ions were βSc/Ti = 100 and βSc/Zr = 38 at pH4.6 on extraction with VA10 + TBP from aqueous solutionof Sc3+–Ti4+–Zr4+. Stripping efficiency of 100, 8 and 22% could be achieved for Sc3+, Ti4+ and Zr4+, respectively by using 0.5 mol/dm3 H2SO4. From these results, it was possible to separate Sc3+from impurities such as Ti4+ and Zr4+ by countercurrent multistage extraction, and Sc3+ was recovered by one-stage stripping with 0.5 mol/dm3 H2SO4. Extraction of Sc3+from the dilute aqueous solution containing 500 mg/dm3 of Sc3+reached 99% at the flow ratio (A/O) = 1.01 in the two-stage countercurrent extraction, and Sc3+ in the organic phase was stripped to attain a six-fold concentration by applying one-stage stripping with flow ratio of (O/A) = 6.00.

A systematic research on solvent extraction process for extracting 233U from irradiated thorium

In consideration of the lack of systematic investigations on solvent extraction process and equipments for extracting 233U from irradiated thorium, an extraction process using TBP (Tri-n-butyl phosphate) as extractant was proposed, optimized and verified. First, the process parameters, including concentration of TBP and HNO3, phase ratio, are preliminary selected. Then, a multistage countercurrent extraction using batch simulation is used to further optimize the parameters. Finally, the extraction process is verified through the continuous multistage countercurrent extraction using both mixer settler and centrifugal extractor, and the process operation efficiency is estimated by equilibration time and concentration profiles of Th and U after equilibrium.

Di-1-methyl heptyl methylphosphonate (DMHMP): A promising extractant in Th-based fuel reprocessing

In this paper, the physical properties of tri-iso-amyl phosphate (TiAP), tri-sec-butyl phosphate (TsBP) and di-1-methyl heptyl methyl phosphonate (DMHMP) were studied and compared with tri-n-butyl-phosphate (TBP). Furthermore, the extraction behaviors of U(VI), Th(IV), nitric acid and fission products, and the extraction capacity of Th(IV) in different extractants were also investigated. The results indicated that the physical and extraction properties of DMHMP were better than that of other extractants and it is more appropriate to be used in thorium-based fuel reprocessing. A thorium-uranium co-decontamination process using DMHMP as extractant was proposed, optimized and verified by multistage countercurrent extraction using batch simulation and centrifugal extractors. By comparison with conventional Thorex process using TBP as extractant, it is found that DMHMP is more promising in thorium-based fuel reprocessing.

Radiolytic degradation of a new diglycol-diamide ligand for actinide and lanthanide co-extraction from spent nuclear fuel

Within the Partitioning and Transmutation strategies, great efforts have been devoted in the last decades to the development of lipophilic ligands able to co-extract trivalent Lanthanides (Ln) and Actinides (An) from spent nuclear fuel. Because of the harsh working conditions these ligands undergo, it is important to prove their chemical and radiolytic stability during the counter-current multi-stage extraction process. In the present work the hydrolytic and radiolytic resistance of the freshly prepared and aged organic solutions containing the new ligand (2,6-bis[(N-methyl-N-dodecyl)carboxamide]-4-methoxy-tetrahydro-pyran) were investigated in order to evaluate the impact on the safety and efficiency of the process. Liquid–liquid extraction tests with spiked solutions showed that the ligand extracting performances are strongly impaired by storing the samples at room temperature and in the light. Moreover, the extracting efficiency of the irradiated samples resulted to be influenced by gamma irradiation, while selectivity remains unchanged. Preliminary mass spectrometric data showed that degradation is mainly due to the acid-catalysed reaction of the ligand carboxamide and ether groups with the 1-octanol present in the diluent.