Aqueous Phase Flow Rate Research Articles

Mass transfer phenomena of partially miscible liquids under liquid-liquid slug flow in a circular microchannel

Microreactors have been demonstrated to become an effective tool for increasing mass and heat transfer in heterogeneous chemical processes that are unachievable in batch or continuous stirred tank reactors. The key to superior performance is the availability of a large specific surface area (A/V) in the microsystem for mass and heat transfer between phases. Among the flow patterns generated in the two-phase liquid-liquid flow, slug is an ideal flow with a high stability characteristic, regular velocity, and uniform dimension throughout a microchannel system. The flow behavior gives slugs great potential to increase mass and heat transfer between phases, so optimizing the utilization of microreactors in many chemical process applications needs an in-depth understanding of the liquid-liquid hydrodynamic. Therefore, the current work aims to determine the mass transfer coefficient under liquid-liquid slug flow and the influence of slug dimensions, channel material, volumetric flow rate, and the flow rate ratio of the organic-aqueous phase on the mass transfer coefficient. The experiments were performed in 1 mm (ID) circular PTFE and silicone tubes, with a 30–40 ml/hour flow rate, and sodium hydroxide concentrations of 0.1, 0.13, and 0.15 M were used. The results exhibit that the most prominent overall mass transfer coefficient was 0.121/s, attained at 0.15 M sodium hydroxide concentration, with 40 ml/hour total discharge within the silicone channel. Microchannels generated smaller slug sizes at a higher aqueous phase flow rate than the organic phase. The smaller size provided a large specific surface area (A/V) for enhancing the mass transfer coefficient.

Enhancement of phenol recovery from wastewater by nanofluid utilizing liquid-liquid extraction method in a membrane-based contactor

This study aims to investigate the effect of adding nanoparticles (NPs) to phenol solvent on the recovery of phenol from wastewater by applying the liquid-liquid extraction technique in a contactor of a hollow fiber membrane. The resulting solution, called nanofluid, is composed of dispersed SiO2 nanoparticles in a 10% (v/v) tributyl phosphate (TBP) /kerosene mixture. The solvent loaded with phenol was regenerated using NaOH solution in a stripping hollow fiber membrane contactor. The stability of SiO2 NPs in the nanofluid was also investigated. Furthermore, the influence of operating conditions, such as NPs concentration, organic phase flow rate (Qorg), aqueous phase flow rate (Qaqu), and inlet phenol concentration on extraction efficiency (ηextrac), extraction flux (Jextrac), and stripping efficiency (ηstripp) were evaluated. The results showed that after 24 h, approximately 80% of the initial dispersion of SiO2 NPs into the nanofluid was achieved. Furthermore, it was observed that adding NPs to the TBP/kerosene solution improved ηextrac, Jextrac, and ηstripp. Among the studied NPs concentrations, 0.02 wt% exhibited higher values of ηextrac, Jextrac, and ηstripp. Additionally, it was found that increasing Qorg led to a significant increase in ηextrac and Jextrac, but a decrease in ηstripp. Conversely, increasing Qaqu led to a decrease in both ηextrac and ηstripp, but an increase in Jextrac. At an inlet phenol concentration of 1000 ppm and with Qorg and Qaqu at the same value of 150 mL min−1, the use of a solvent containing 0.02 wt% SiO2 NPs resulted in ηextrac of 97.8% and ηstripp of 97.7%.

DEVELOPMENT, OPTIMIZATION AND VALIDATION OF HPLC METHOD FOR ASSAY AND DISSOLUTION TESTING OF FUROSEMIDE TABLET FORMULATION UTILIZING DESIGN OF EXPERIMENT APPROACH

A robust HPLC method was developed and validated for the quantitative estimation of furosemide tablet and dissolution testing. The optimization of chromatographic conditions (% organic phase, flow rate and pH of aqueous phase) was done using the Box-Behnken experimental design. The creation of a reliable HPLC technique utilised the design of experiments methodology effectively. The furosemide peak was found to have a Rt value of 4.86 min under the optimal HPLC settings, which included a C18 (250 mm 4.6 mm, 5 m) column and a methanol: aqueous solution of formic acid buffer (0.2 % V/V, pH 2.5) as mobile phase.The optimized method was validated according to ICH Q2(R1) guideline. Using a fractional factorial design with six chromatographic components, the robustness of the approach was evaluated. The results showed that a multivariant approach was successfully used to improve a reliable HPLC technique for everyday quality monitoring of furosemide in tablet formulations

Scalable and high-throughput production of an injectable platelet-rich plasma (PRP)/cell-laden microcarrier/hydrogel composite system for hair follicle tissue engineering

BackgroundTissue engineering of hair follicles (HFs) has enormous potential for hair loss treatment. However, certain challenges remain, including weakening of the dermal papilla cell (DPC) viability, proliferation, and HF inducibility, as well as the associated inefficient and tedious preparation process required to generate extracellular matrix (ECM)-mimicking substrates for biomolecules or cells. Herein, we utilized gelatin methacryloyl (GelMA) and chitosan hydrogels to prepare scalable, monodispersed, and diameter-controllable interpenetrating network GelMA/chitosan-microcarriers (IGMs) loaded with platelet-rich plasma (PRP) and seeded with DPCs, on a high-throughput microfluidic chip.ResultsThe ECM-mimicking hydrogels used for IGMs exhibited surface nano-topography and high porosity. Mass production of IGMs with distinct and precise diameters was achieved by adjusting the oil and aqueous phase flow rate ratio. Moreover, IGMs exhibited appropriate swelling and sustained growth factor release to facilitate a relatively long hair growth phase. DPCs seeded on PRP-loaded IGMs exhibited good viability (> 90%), adhesion, spreading, and proliferative properties (1.2-fold greater than control group). Importantly, PRP-loaded IGMs presented a higher hair inducibility of DPCs in vitro compared to the control and IGMs group (p < 0.05). Furthermore, DPC/PRP-laden IGMs were effectively mixed with epidermal cell (EPC)-laden GelMA to form a PRP-loaded DPC/EPC co-cultured hydrogel system (DECHS), which was subcutaneously injected into the hypodermis of nude mice. The PRP-loaded DECHS generated significantly more HFs (~ 35 per site) and novel vessels (~ 12 per site) than the other groups (p < 0.05 for each).ConclusionTaken together, these results illustrate that, based on high-throughput microfluidics, we obtained scalable and controllable production of ECM-mimicking IGMs and DECHS, which simulate an effective micro- and macro-environment to promote DPC bioactivity and hair regeneration, thus representing a potential new strategy for HF tissue engineering.

Extraction of hexavalent chromium from wastewater using novel rotating zigzag contactor

ABSTRACT HIGEE (an acronym of high gravity) devices have attracted considerable attention among the researchers due to its immense process intensification capability. In order to achieve desired process efficiency this technology replaces terrestrial acceleration by centrifugal one (typically 1000g) which can be attained by rotating a specially shaped rigid bed. This study focuses on liquid–liquid extraction of hexavalent chromium [Cr(VI)] from wastewater using aliquat-336 as an extractant inside a novel rotating zigzag contactor (RZC). Extraction efficiency of RZC were observed with the variation in pH (2–10), rotational speed (300–1100rpm), aqueous phase (0.4–1.2 L-min−1) and organic phase (0.05–0.15 L-min−1) flow rate, feed (25–200 mg-L−1) and extractant (0.5–1.25 vol%) concentration. The results obtained from this study showed a significant improvement in extraction efficiency (85–99%) with the variation in rotational speed (300–1100rpm). It was observed that the efficiency increased with rotational speed, total flow rate and the organic phase flow rates but decreased with the feed concentration and pH of the aqueous solution. Comparison with some conventional contactors reveals that the extraction efficiency obtained in RZC was nearly 40–50% higher under the same operating conditions.

New liquid-liquid extraction column with random packed agitation structure for heavy metal removal and hydrodynamic evaluation

A new random packed agitation column was presented to enhance the evaluation of dispersed phase holdup and hydrodynamic velocities. The extraction of cobalt ions from an aqueous to organic phase was observed under operating conditions. The interaction and association between operating parameters (rotor speed, aqueous phase flow rate (Qc), and organic phase flow rate (Qd)) were investigated by designing response surface methodology (RSM). Quadratic models for three responses (holdup (φ), slip velocity (Vs), and extraction efficiency (%E)) were obtained by statistical analysis. The achieved optimal conditions included 203 rpm of rotor speed, 32 L/h of Qd and 28 L/h of Qc. The model outcomes were 0.094, 10.57 mm/s, and 99.91% for φ, Vs, and %E, respectively. Comparison between results obtained from the central composite design approach and artificial neural network (ANN) proved that both techniques had a high ability to predict the experimental data, but the ANN technique had a higher coefficient of determination (0.9999) and lower error. The cobalt recovery can be significantly increased using higher rotor speed and phase flow rates. The data clearly demonstrates that the column configuration can be applied with high efficiency for the recovery of cobalt ions or other elements from secondary sources.

Feasibility of pilot-scale disc-donut column for continuous cadmium extraction with the perspective of droplet size distribution

ABSTRACT Heavy metal removal is a significant problem in various industries. Liquid-liquid extraction is a practical process in recovering these elements. In this study, the behavior of pilot-scale disc-donut column in the extraction of cadmium ions was evaluated. The effects of droplets with the variation size distributions are significant in describing performance and characteristics of an extractor for removing the substrate from aqueous or organic phases. The size distribution of droplets is relative to the interfacial area under steady conditions. To match the size distribution of droplets, the experiments are carried out in reaction and non-reaction conditions. In emulsion regime (pulsing intensity (Af), inlet organic and aqueous phase flow rate (Vc, Vd) equal to 3.3 cm/s, 2.22 mm/s, and 2.22 mm/s, respectively) and under the optimized conditions, 99.7% of the cadmium can be recovered from the aqueous solution. It was found that Weibull distribution gives the best fit at each operation mode while inverse Gaussian distribution gives the most inferior fit. According to a series of statistical analyses, it is shown that the pulsation intensity imposed more influence on drop sizes, and superficial flow rates of both phases are less able to the successful prediction of size distribution of droplets.

Microfluidic synthesis of magnetic nanoparticles in droplet-based microreactors

Microfluidic devices have been widely used to achieve highly controlled synthesis of various nanomaterials including inorganic materials, polymers and composite materials via continuous microreactors. Here, droplet-based continuous microreactors generated in a microfluidic device are used to synthesize magnetic nanoparticles (Fe3O4) via simple coprecipitation method. The chip is composed of multifunctional units, including T-junction for droplet generation, Y-junction and S-channels for droplet fusion and rapid mixing as well as the observation of the formation process of nanoparticles. The size of water-in-oil droplets was inspected by tuning the flow rate of aqueous and oil phase. By changing the temperature and flow rate of aqueous and oil streams, we investigated the variation of the morphology, size, saturation magnetization and coercivity of nanoparticles. This work presents that chemical reaction can be initiated by fusing two aqueous droplets due to the hydrodynamic coupling, which is superiorly efficient compared to the conventional coprecipitation method for synthesizing Fe3O4 nanoparticles of high saturation magnetization and low coercivity.

Flow regime mapping for a two-phase system of aqueous alginate and water droplets in T-junction geometry

Microfluidic systems are an interesting topic for investigation due to their wide-spreading applications. Nowadays, polymeric solutions are used mainly for the generation of microparticles in biomedical engineering, food, and pharmaceutical industries. Droplet-based microfluidic devices have proposed an extensive interest in many applications such as chemical/biological/nanomaterial preparation to understand deeply the droplet size and formation in microchannels. However, numerous experimental and numerical studies have been done for oil–water combination, polymeric solutions behavior in the presence of oil has not been investigated widely. Therefore, it is important to understand the droplet formation mechanisms in a microfluidic device for both water and polymeric solutions to determine the flow regime mapping in order to control the characteristic of the produced droplets. Also, in many studies, the length of the droplets as a parameter to investigate the droplet size was studied. In this study, droplet generation in the T-shaped microfluidic junction with an enlarged horizontal outlet channel was studied to have opportunity to determine the diameter of spherical droplets. The water and the alginate 1% (w/v) solutions were used separately as a dispersed phase, and the mineral oil was used as the continuous phase in which the solution's flow rates were varied over a wide range. To perform numerical simulations of the droplet formation, a two-phase level set method was used which is a suitable method for the investigation and simulation of immiscible fluids. The flow regime mapping for the two different aqueous solutions was obtained. Furthermore, the influences of flow rates on droplet size, droplet generation frequency was quantified. In this study, flow regime, droplet size, and droplet frequency were studied. In general, flow rates of the oil and aqueous fluids readily control five main flow regimes including backflow, laminar flow, dripping flow, squeezing flow, jetting flow, and fluctuated flow. It was observed that generated droplets with alginate solution as dispersed phase were more in the region of the jetting flow regime while water droplets were more in the region of the dripping flow regime, this can be due to the difference in characteristics of polymeric solution and water. For both aqueous phases, larger droplets were obtained when flow rates of oil were decreased and aqueous phases were increased. Also, the frequency of droplet generation increases and decreases by increasing oil phase flow rate and increasing aqueous phase flow rate, respectively. In the same flow rates of aqueous phase and oil, the sizes of water droplets are larger than the alginate droplets and also water has a higher frequency of droplet generation compared to alginate. Finally, we characterized all the obtained data for flow regimes due to the capillary number (Ca) of the continuous phase. The findings of this study can help for better understanding of the detailed process of droplet generation of water and alginate solution as dispersed phase separately with mineral oil as the continuous phase in a T-junction geometry microfluidic and know the effect of characteristics of solutions as a dispersed flow in flow regimes.

Novel Microfluidic Device for the Preparation of Multiple Microproducts

Double-layered microbubbles, microdroplets, and a mixture of microproducts were fabricated by a novel device of the geometric combination of a Y-junction and a flow-focusing junction in this study. An air-in-oil-in-water microbubble was used as a template for the preparation of double-layered microbubbles. The oil-in-water microdroplets and multiple microproducts could be generated in this system at the same time. To observe the evolution of the multiphase flow in a microchannel, high-speed microscopy and digital imaging technologies were applied. The fluidic mechanisms of generating specific microproducts under different operating conditions were investigated through the analysis of the flow patterns. The analysis of the microproduct generation process showed that operating conditions such as the air pressure and oil- and aqueous-phase flow rates had a significant impact on the size, generation frequency, and monodispersity of the microproducts. Dimensional analysis was applied to predict the diameters of the microproducts and showed a good agreement. Finally, the method to promote the emulsion stability was obtained.

Quality-by-Design Approach for Chromatographic Analysis of Metformin, Empagliflozin and Linagliptin.

New analytical quality by design-oriented HPLC method with multiple response optimization (Derringer's desirability function) was demonstrated for simultaneous analysis of three antidiabetic drugs (metformin hydrochloride/empagliflozin/linagliptin) in a fixed-dose combination. Central composite design was employed for systematic optimization of critical method parameters, namely, % organic phase (X1), aqueous phase pH (X2) and flow rate (X3) while resolution, capacity factor and theoretical plate number as critical analytical attributes. Effective chromatographic separation of title analytes was accomplished on Std. Discovery C18 column at 30°C with mobile phase comprising acetonitrile: phosphate buffer pH5 (38:62% v/v), pumped at a flow rate of 1mL/min by isocratic elution pattern and UV detection at 222nm. The model is rectilinear in the range of 1.0-200, 0.2-40 and 0.1-20μg/mL at retention times of 3.04, 3.93 and 5.99min for metformin, empagliflozin and linagliptin, respectively. The method obeyed all validation parameters of ICH Q2(R1) guidelines. The proposed HPLC method was highly robust for method transfer, regulatory flexibility within design space and can be used for assay of pharmaceutical dosage forms comprising these analytes. The proposed method was applied for stability studies of drugs under various stress conditions.

Testing the Implementation of a Pilot-Scale Kühni Column in Reactive and non-Reactive Condition

ABSTRACT In this study, the primary efforts focused on using the Kühni extraction column with optimal energy and extraction efficiency for the removal of zinc ions from aqueous solution. The implementation of the extractive column was investigated in the reactive and non-reactive conditions. The experimental works illustrate that the extraction efficiency and hydrodynamic parameters, particularly depend on the energy input, phase flow rates as well as on the physical properties of the aqueous and organic phases. Among the operating parameters, the choice of the appropriate range for rotation speed plays a significant role for the removal of zinc ions in the pilot-scale Kühni column. The results showed that in the optimal condition for rotation speed, aqueous phase flow rate, and dispersed phase flow rate equal to 181 rpm, 33 L/h, and 21 L/h, respectively, the amount of zinc extraction reaches a maximum of 99.58%.

Parametric study of catalytic co-gasification of cotton stalk and aqueous phase from wheat straw using hydrothermal carbonation

Parametric study of catalytic co-gasification of cotton stalk (CS) and aqueous phase from wheat straw (WS-AP) using hydrothermal carbonation (HTC) was conducted to investigate the effects of catalysts, temperature, and flow rate of aqueous phase on the quality and volume of syngas. Olivine (OL), iddingsite (ID), and xiuyan jade (XY) and those calcined for 4 h at 900 °C, namely, C-OL, C-ID, and C-XY, were found to be rich in metal oxides, e.g., MgO (0.24–41.3 wt%), Fe2O3 (6.68–12.4 wt%), and SiO2 (47.8–84.7 wt%), and all of them exhibited a well-developed pore structure. Catalytic co-gasification experiments of ternary blends of CS, WS-AP, and the catalysts were conducted. The addition of six different catalysts improved syngas molar rate (H2/CO). The order by which the catalysts produced H2 yield was C-OL>C-ID>C-XY>ID>OL>XY. C-OL exhibited the highest catalytic behavior with H2 content of 53.6 vol%. The effects of temperature were investigated further. Syngas yield of 1429 mL/g with an H2/CO molar ratio of 2.8 was obtained in the presence of C-OL at 900 °C. Similar results were obtained by decreasing the flow rate of aqueous phase. The maximum syngas yield of 1595 mL was observed in the presence of C-OL at a flow rate of 0.3 mL/min and an H2/CO molar ratio of 2.36. The results confirmed the synergistic effects of CS, WS-AP, and the catalysts due to mineral catalytic effects during co-gasification. This work suggested that C-OL is a potential additive catalyst for handling waste aqueous phase at of co-gasification wastes and for improving syngas quality and yield.

Selective separation of Cu from large excess of Zn using a microfluidic platform

A microfluidic platform, comprising a 800 μm diameter microbore tube connected to a 750 μm diameter opposed T-junction, to selectively extract copper from a large excess of zinc is reported. The effects of flow velocity (0.033 – 0.167 m/s) and ratio of the organic phase flow rate to the aqueous phase flow rate (O/A ratio, 1−2.5) on percent Cu extraction, Cu selectivity, stage efficiency, and overall volumetric mass transfer coefficient are studied. At O/A ratio of unity, maximum stage efficiency (98.90%) and maximum value of overall volumetric mass transfer (0.039 s−1) are obtained at flow velocity of 0.167 m/s. At these operating conditions, the values of % Cu extraction and Cu selectivity are 79.10% and 54.25%, respectively. Back extraction/stripping studies are also carried out to recover Cu in pure form in the strippant phase. Cu purity as high as 99% is obtained for O/A ratio of 1 and flow velocity of 0.167 m/s. High speed imaging studies are carried out to investigate the liquid-liquid two-phase flow pattern in the microchannels both during extraction as well as stripping.

Mass transfer studies in RDC column by the coupling effects of perforated structure and reactive extraction of Mo(VI) and W(VI) from sulfate solution

Solvent extraction of molybdenum (VI) and tungsten (VI) by synergism of the mixture of D2EHPA and TBP were conducted in the RDC extractor with perforated structure. The initial aqueous pH, extractant concentration, ammonium hydroxide concentration as a stripping agent, and synergistic enhancement factor were optimized in the initial experiments before collecting column data. In the RDC column, the influence of agitation rate and inlet phase velocities were examined on the hydrodynamic velocities, mass transfer data, and distribution coefficients. The finding data indicated that the impact of agitation speed on the distribution coefficients of molybdenum and tungsten is considerable in comparison the inlet phase flow rates. Published empirical models for estimating the slip and characteristic velocities were compared with the solvent extraction data, and the modified models were presented by considering the reactive extraction. Mass transfer performance based on the dispersed phase was studied by applying the axial dispersion model. Column performance enhances the increment of the operational variables such as agitation speed, inlet solvent phase flow rate, and inlet aqueous phase flow rates, but the variations of agitation speed and solute transfer direction have a high impact on this phenomenon. The previous models for estimating the mass transfer coefficients were compared with the present work. The published models failed to acceptable estimate the mass transfer evaluation due to column geometry and reactive extraction systems. Finally, the new models were proposed by using the dimensionless analysis methods for obtaining the enhancement factor in both extraction and stripping stages.

Modelling tyramine extraction from wastewater using a non-dispersive solvent extraction process.

Wastewater effluent from alkaloid processing plants has the potential adverse environmental influences. Mathematical modelling and simulations were carried out using computational fluid dynamics of mass and momentum transfer in a hollow fibre membrane extractor. Conservation equations were derived for tyramine extraction in the membrane extractor and solved based on the finite element method. Model findings based on the computational fluid dynamics validated well with the experimental data. The results showed that increase in organic-phase flow rate, as well as the fibre length and its porosity, has a positive impact on the performance of the extractor, whereas the enhancement of aqueous-phase flow rate led to the reduction of tyramine extraction.

Process Intensification of Liquid-Liquid Extraction in Rotating Packed Bed

The object of this study is to intensify the liquid-liquid extraction. Experiments were carried out inside a Rotating Packed Bed (RPB) operating at centrifugal force varying between 100g and 1000g. The system chosen for experimentation was removal of hexavalent chromium from aqueous solution using aliquat-336 as an extractant. The effect of centrifugal force on overall volumetric mass transfer coefficient () was investigated. Mass transfer characteristics of RPB were observed with the variation in rotational speed (300-1100rpm), aqueous phase (0.4-1.2 L/min) and organic phase (0.05-0.15 L/min) flow rate, feed (25-200 mg/L) and extractant (0.5-1.25 vol%) concentration. Significantly higher value of (~20-25 times) was achieved in RPB than that achieved in comparison with conventional packed bed extractor wherein flow is dictated by terrestrial gravity. In other words, same separation efficiency can be obtained within a much smaller rotating extractor.

Wall-jet ion sensor based on ion transfer processes at a polarized room-temperature ionic liquid membrane

Room-temperature ionic liquid (RTIL) membrane is used to construct a wall-jet ion sensor based on the ion transfer processes at a polarized interface between RTIL and an aqueous electrolyte solution. The stream of the aqueous phase with an injected sample plug containing an electroactive ion is led against the RTIL membrane through a silver tube, which is covered with an AgCl layer, and which serves simultaneously as one of two reference electrodes in a four-electrode cell. The effects of the applied potential, the ion concentration, the volume flow rate of the mobile aqueous phase, and the injected sample volume on the chronoamperometric response of the sensor to the test samples containing tetraethylammonium cation (TEA+) as a model ion are demonstrated. The applicability of the available theory of the wall-jet electrode against which a vertical stream is flowing that is much smaller in diameter than the electrode is confirmed for this sensor. Analytical characteristics for the flow injection analysis of the studied model ion are estimated including excellent repeatability characterized by the relative standard deviation (1.64%) of the average current at the ion concentration (0.5 μmol dm−3), a low limit of detection (22.5 nmol dm−3), and the wide linear dynamic range exceeding three orders of magnitude (1 × 10−7–2 × 10−4 mol dm−3).

Conversion of Glucose to 5-Hydroxymethylfurfural in a Microreactor.

5-hydroxymethylfurfural (5-HMF) is one of the key bio-based platform chemicals for the production of high-value chemicals and fuels. The conventional production of 5-HMF from biomass is confronted by the relatively low yield and high production cost. In this work, the enhancement of a continuous catalytic synthesis of 5-HMF in a biphasic-dispersed flow reactor was proposed. Glucose, hydrochloric acid, and methyl isobutyl ketone (MIBK) were used as a low-cost raw material, catalyst, and organic solvent, respectively. The main factors (reaction temperature, residence time, solvent amount, and catalyst concentration) affecting the yield and selectivity of 5-HMF were studied. The 5-HMF yield of 81.7% and 5-HMF selectivity of 89.8% were achieved at the residence time of 3 min, reaction temperature of 180°C, the volumetric flow rate of aqueous phase to organic phase of 0.5:1, and catalyst concentration of 0.15 M. The yield and selectivity of 5-HMF obtained from the biphasic system were significantly higher than that obtained from the single phase system. The superior 5-HMF production in our system in terms of operating conditions was presented when compared to the literature data. Furthermore, the continuous process for removing HCl from the aqueous product was also proposed.

Microfluidic solvent extraction of calcium: Modeling and optimization of the process variables

In this study, a new systematic method was proposed for the highly efficient separation of species with very low separation factor. Here, solvent extraction and microfluidic technology were integrated for the extraction and separation of Ca2+ion. A cyclic compound (DC18C6) was used as the selective extractant. Full separation of organic and aqueous phases at the end of the microchannel was achieved by exploiting a flow regime map. N-butyl acetate was chosen as organic solvent among from other potential candidates with different characteristics. The Box-Behnken experimental design was used to provide data for modeling, while the variables of the model were DC18C6 concentration, flow rate and pH of the aqueous phase. The results showed that Ca2+ extraction efficiency was 62.28% under the optimum conditions: DC18C6 concentration was 0.014 M, the aqueous phaseflow rate was 20 µl/min and pH of the aqueous phase was 5.1. Multi-stage microfluidic solvent extraction in series was performed and the possibility of numbering-up with maintaining full phase separation was demonstrated. The overall volumetric mass transfer coefficients were determined quantitatively in a single microchannel, and their values were in the ranges of 0.19–0.41 s−1, which are two orders of magnitude higher than those of conventional liquid-liquid contactors.