Hydrodynamic Filtration Research Articles

The impact of diffusiophoresis on hydrodynamic dispersion and filtration in porous media

It is known that the dispersion of colloidal particles in porous media is determined by medium structure, pore-scale flow variability and diffusion. However, much less is known about how diffusiophoresis, that is, the motion of colloidal particles along salt gradients, impacts large-scale particle dispersion in porous media. To shed light on this question, we perform detailed pore-scale simulations of fluid flow, solute transport and diffusiophoretic particle transport in a two-dimensional hyper-uniform porous medium. Particles and solute are initially uniformly distributed throughout the medium. The medium is flushed at constant flow rate, and particle breakthrough curves are recorded at the outlet to assess the macroscopic effects of diffusiophoresis. Particle breakthrough curves show non-Fickian behaviour manifested by strong tailing that is controlled by the diffusiophoretic mobility. Although diffusiophoresis is a short-time, microscopic phenomenon owing to the fast attenuation of salt gradients, it governs macroscopic colloid dispersion through the partitioning of particles into transmitting and dead-end pores. We quantify these behaviours by an upscaled analytical model that describes both the retention and release of colloids in dead-end pores and the observed long-time tailings. Our results suggest that diffusiophoresis is an efficient tool to control particle dispersion and filtration through porous media.

A hydrodynamic-based dual-function microfluidic chip for high throughput discriminating tumor cells

A hydrodynamic-based microfluidic chip consisted of two function units that could not only separate tumor cells (TCs) from whole blood but also remove residual blood cells was designed. The separation of TCs was achieved by a straight contraction-expansion array (CEA) microchannel on the front end of the chip. The addition of contractive structure brought a micro-vortex like Dean vortex that promoted cell focusing in the channel, while when cells entered the dilated region, the wall-induced lift force generated by the channel wall gave cells a push away from the wall. As the wall-induced lift force is proportional to the third power of the cell diameter, TCs with larger diameter will have a larger lateral migration under the wall-induced lift force, realizing the separation of TCs from blood sample. Fluorescent particles with diameters of 19.3 μm and 4.5 μm were used to simulate TCs and red blood cells, respectively, to verify the separation capacity of the proposed CEA microchannel for particles with different diameter. And a separation efficiency 98.7% for 19.3 μm particles and a removal rate 96.2% for 4.5 μm particles was observed at sample flow rate of 10 μL min−1 and sheath flow rate of 190 μL min−1. In addition, a separation efficiency about 96.1% for MCF-7 cells (stained with DiI) and removal rates of 96.2% for red blood cells (RBCs) and 98.7% for white blood cells (WBCs) were also obtained under the same condition. However, on account of the large number of blood cells in the blood, there will be a large number of blood cells remained in the isolated TCs, so a purification unit based on hydrodynamic filtration (HDF) was added after the separation microchannel. The purification channel is a size-dictated cell filter that can remove residual blood cells but retain TCs, thus achieving the purification of TCs. Combined the CEA microchannel and the purifier, the microchip facilitates sorting of MCF-7 cells from whole blood with a separation rate about 95.3% and a removal rate over 99.99% for blood cells at a sample flow rate of 10 μL min−1, sheath flow rate of 190 μL min−1 and washing flow rate of 63 μL min−1.

DETERMINATION OF THE DEGREE OF INFLUENCE OF HYDRODYNAMIC PRESSURE DROP AND CAPILLARY PRESSURE ON THE DEPTH OF THE ZONE OF PENETRATION OF FILTRATE OF WASHING FLUID INTO THE FORMATION

When mud filtrate is introduced into the formation, its rate of advancement is determined by hydrodynamic and capillary forces. Hydrodynamic forces act at a distance between points of different pressures. Unlike hydrodynamic forces, capillary pressure acts locally, at the interface. In some cases, when hydrodynamic filtration in the formation is not carried out, the entry of washing fluid is due to capillary penetration. The ratio of forces depends on changes in pressure, water supply, interfacial tension, radius of porous channels and a number of other factors. The calculation method proposed in the article allows to determine the values of the radius of the pore channels and the distance from the well at which the equality of hydrodynamic and capillary forces will be observed. A plot of the dependence of the hydrodynamic force difference and capillary pressure equation on the radius of the porosity channels determined by the distance of the radius from the well is described.

Mesoscopic simulation of multi-scheme particle separation in deterministic lateral displacement devices using two-piece hybrid pillars

Pillar shape exploration in deterministic lateral displacement (DLD) technique holds great promise for developing high-performance microfluidic devices with versatile sorting schemes. A recent innovative design using filter-like micropillars was proposed to improve cell separation, but its significance might be greatly underestimated due to an inaccurate understanding of the underlying mechanism. In this study, we employ mesoscopic hydrodynamic simulations to explore the movement and separation of rigid spherical particles in DLD arrays using various two-piece hybrid (TPH) pillars, where each pillar consists of two individual pieces separated by a tunable inter-piece channel. In comparison with the conventional one-piece pillars, the back piece of TPH-pillars is found to hierarchically tailor the flow profile of the front piece on the basis of the row shift fraction and the inter-piece channel width, resulting in unique tunable multi-scheme separation at low, intermediate, and high row shift fractions, respectively. At the intermediate regime, in particular, the first flow lane that determines the critical separation size could be physically fenced out by the inter-piece channel, and a delicate coupling of hydrodynamic filtration and DLD has been revealed to induce a constant critical size in the whole regime. This work theoretically demonstrates the feasibility and significance of TPH-pillars, which may open up a new direction of the geometry design by exploiting rich multi-piece hybrid structures to expand the versatility of the DLD technique.

Analysis of hydrodynamic filtration performance in a cross-step filter for drip irrigation based on the CFD‒DEM coupling method

Analysis of hydrodynamic filtration performance in a cross-step filter for drip irrigation based on the CFD‒DEM coupling method

Abstract 3382: Detection of CTCs using a micro-channel combined fluid dynamics and electrophoresis in colorectal cancer

Abstract Background: Circulating tumor cells (CTCs) are tumor cells that can be isolated from peripheral blood. Investigation of CTCs might allow comprehensive studies at the DNA, RNA, and protein. However, fewer CTCs generally can be collected from patients with colorectal cancer, limiting the possibility of clinical applications of CTC analysis despite the development of many different methods. We have developed a micro-channel device that integrates hydrodynamic filtration (HDF) capable of size separation and dielectrophoresis (DEP) capable of electrical property separation, using peripheral blood from colorectal cancer patients. Method: A separation test was performed using a whole peripheral blood sample obtained from colorectal cancer patients with KRASmutation in the tumor tissue. The sample blood was diluted 2-fold with PBS, and red blood cells and plasma were removed using HDF. After that, Leukocytes and CTCs were separated in the same channel by DEP. DNA was extracted from CTCs (port 1) and leucocyte fraction (port 2), and KRAS mutations were detected using droplet digital PCR. In order to evaluate the separated fractions, microwell slide was used for evaluation by nuclear staining, CD45 and EpCAM antibody staining. Results: 52 colorectal cancer patients were participated. The median age of patients was 71 years, 38 (73%) were male. Twenty-eight (53.9%) had colon cancers. Four stage III and 48 stage IV patients were included. The quality of DNA extracted from all patients were suitable for molecular genetic analysis. The DNA concentration of port 1 was significantly lower than that of port 2 (371 ng/mL vs 36667 ng/mL, P<0.001). Using droplet digital PCR, KRAS mutations were detected in the port 1 of 8 (15.4%) patients and in port 2 of 15 (28.8%) patients. In 35.5% of patients, KRAS mutations were detected in either port 1 or port 2. Conclusion: This device does not require pretreatment and is easy to extract CTCs. Since CTCs are contaminated with the leukocyte fraction, it is necessary to improve the accuracy of CTCs collection by adjusting the conditions of DEP. Citation Format: Ryo Ohta, Takeshi Yamada, Nobuhiko Taniai, Hiroshi Yoshida. Detection of CTCs using a micro-channel combined fluid dynamics and electrophoresis in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3382.

Development and Applications of Cell Sorters Based on Hydrodynamic Filtration

Cell sorters is one of the key topics of physical research today. Cell sorters can sort cells, and through this process, specific cell types can be distinguished from other cell types contained in the sample based on the physical or biological properties of the sample. The homogeneous cell population obtained after sorting can be used for a variety of applications, including research, diagnostics and therapeutics. Researchers have made significant progress in cell sorters including the design principles optimization design techniques etc. Cell sorters based on hydrodynamic filtration possesses a channel and a sidewall which could be applied in particle transmission. In this paper, the research method, results, main findings in related research about the cell sorters based on hydrodynamic filtration are discussed. Suggestions for the development and application of the sorter based on hydrodynamic filtration are put forward. Overall, this paper could be a useful reference for those who would like to know sorters based on hydrodynamic filtration.

Effects of hydrodynamic cavitation and temperature on nanofiltration performance for concentrating ultrafiltered skim milk

The performance of nanofiltration (NF) as influenced by hydrodynamic cavitation (HC) and filtration temperature during the concentration of milk protein concentrate (MPC) was investigated. Pasteurised skim milk was concentrated using ultrafiltration (UF) to prepare UF retentate (MPC80, 20% total solids, TS), which was then further concentrated using NF at 22°C and 50°C with or without HC treatments until permeate flux declined to 0.1 L/m2/h. Results showed that UF retentate can be concentrated to higher TS (up to 31.5%) at higher filtration temperature or by applying HC, with synergistic effect in combination of both treatments, during NF.

Экспериментальное исследование эффективности гидродинамического фильтрования дизельного топлива

The existing designs of standard fuel treatment filters containing replaceable filter elements have a short service life and do not always fully meet the requirements of highly effi cient fuel filtering. Based of new technical solutions, the authors designed a hydrodynamic filter with hydrophobic screen partition. The filter element with a hydrophobic screen partition was tested at 20°C with diesel fuel DT-5 EURO, class 4, type III according to GOST Р 52368-2005 (ЕН 590:2004) under the standard test procedure of filters and fi lter-separators for ground fuel filtering facilities. The content of mechanical impurities in diesel fuel was determined according to GOST EH 12662-2016. To statistically process research results, the authors used Statgraphics software package. It has been established that in the hydrodynamic filter the separating screen partition No. 004 has optimal cell size and acceptable hydraulic characteristics. The authors conducted a full factorial experiment to estimate the partition’s infl uence on the filtering properties. According to its results, the greatest infl uence on the removal of mechanical impurities at hydrodynamic filtration belongs to the speed of fuel fl ow, the smallest - the partition inclination angle and the concentration of mechanical impurities. The presented regression model of hydrodynamic filtering is useful for forecasting the effi ciency of diesel fuel cleaning. The conducted research is helpful for determining physical operating conditions of the hydrodynamic filter with a hydrophobic screen partition at the designing stage and setting design parameters of filtering partitions to ensure the optimum functioning of the device.

Handheld Microfluidic Filtration Platform Enables Rapid, Low-Cost, and Robust Self-Testing of SARS-CoV-2 Virus.

Here, a novel microfluidic test kit combining ultrahigh throughput hydrodynamic filtration and sandwich immunoassay is reported. Specifically, nano and microbeads coated with two different, noncompetitive antibodies, are used to capture the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) proteins simultaneously, forming larger complexes. Microfluidic filtration discards free nanobeads but retains antigen-bridged complexes in the observation zone, where a display of red color indicates the presence of antigen in the sample. This testing platform exhibits high throughput separation (<30 s) and enrichment of antigen that exceeds the traditional lateral flow assays or microfluidic assays, with a low limit of detection (LoD) < 100 copies mL-1 . In two rounds of clinical trials conducted in December 2020 and August 2021, the assays demonstrate high sensitivities of 95.4% and 100%, respectively, which proves this microfluidic test kit is capable of detecting SARS-CoV-2 virus variants evolved over significant periods of time. Furthermore, the mass-produced chip can be fabricated at a cost of $0.98/test and the robust design allows the chip to be reused for over 50 times. All of these features make the microfluidic test kit particularly suitable for areas with inadequate medical infrastructure and a shortage of laboratory resources.

CORRECT DETERMINATION OF INTEGRAL CONDUCTIVITY IN SOLVING INCORRECT INVERSE PROBLEMS OF ELECTROMAGNEIC LOGGING

The paper suggests and investigates a problem statement of well-logging inverse problem that is based on the integral conductivity parameter to describe a geoelectric section. Approach was introduced for a layered cylindrical model with radially heterogeneous continuous distribution of electric properties that parametrize the problem with a function of total longitudinal conductivity. The results of hydrodynamic modeling for oil/fresh water- and brine-based drilling muds were used to study multiple propagation resistivity tool signal equivalency for two classes of models with continuous and piece-wise constant conductivity distribution. Physically based algorithm enabling one to convert one model class to the other, preserving the signal equivalency was proposed. It was demonstrated that the radial models with different radial conductivity distribution and similar integral conductivity curves are equivalent. This fact lays a rationale of using the integral conductivity parameters along with conductivity while inversion. The integral conductivity parameter can be used to build the functionals, whose minimization improves algorithm stability and enables determining functional parameters in hydrodynamic filtration models.

CFD-DEM simulation of the hydrodynamic filtration performance in balaenid whale filter feeding

Solid-liquid separation is a key link in environmental chemical and process engineering, including water purification, pollution treatment, etc. Traditional industrial filters are often clogged and damaged because they cannot be cleaned or replaced in time. Filter-feeders, on the other hand, are rarely clogged. Therefore, it is of great significance to draw bionic inspiration from biological filtration to guide the design of traditional filters. In this study, a computational fluid dynamics (CFD) and discrete element method (DEM) coupled model is adopted to investigate the filtering mechanism in balaenid whale feeding. In this model, DEM is used for the particle and the Navier-Stokes equation is used for the fluid. The effects of particle space and shape, as well as particle-particle/wall interaction, are considered. Then, the model is validated by comparing some crucial information with the theoretical results of previous literature. Finally, the effects of four key parameters on the filter feeding characteristics are analyzed, including the fringe layer permeability, prey incident direction, size and shape. The results show that the large permeability, random incidence direction, large size and real irregular shape all lead to more particle collisions. Besides, the captured prey is prone to form an uneven, backward aggregation trend. The large permeability and size make the trend of posterior aggregation more obvious. However, there are no significant differences in the number of the captured prey at each location for different types of incident directions or prey shapes. But the variation of the captured prey distribution in the real shape case is not as smooth as in the simplified sphere case, which shows that the increase in collisions changes the trajectories of some particles to some extent. This study provides a new idea for bionic design in solid-liquid separation field.

On the structure of the orthotropic 3D permeability tensor of an anisotropic porous body in heat and mass transfer problems

The structure of a 3D permeability tensor with orthotropic properties is proposed to describe various heat and mass transfer processes in anisotropic porous media. This structure of the permeability tensor has advantages over the monoclinic and triclinic because of the minimum number of elements to be determined, which greatly simplifies the formulation, conduct and processing of the corresponding experiments. In addition, the confirmation of the operability of such a structure opens up new opportunities for the artificial creation of porous materials with specified properties and the required anisotropy architecture on 3D printers. Using the Jacobians of rotations in the Cartesian reference system, the matrix of rotations is found as a result of successive multiplication of Jacobians by different angles around the axes of the base coordinate system. The final form of the tensor is identified as the product of the orthotropic tensor on the left and right by the turn matrix and the transposed turn matrix, respectively. This representation allowed us to calculate the inverse permeability tensor and synthesize a mathematical 3D model of Darcy-Brinkman type of unidirectional flow in a porous channel of rectangular cross-section on the example of hydrodynamic filtration of a Newtonian fluid. It is shown that such linearization does not level the property of anisotropy in a porous medium, while maintaining three-dimensionality.

Towards Microfluidic-Based Exosome Isolation and Detection for Tumor Therapy.

Exosomes are a class of cell-secreted, nano-sized extracellular vesicles with a bilayer membrane structure of 30-150 nm in diameter. Their discovery and application have brought breakthroughs in numerous areas, such as liquid biopsies, cancer biology, drug delivery, immunotherapy, tissue repair, and cardiovascular diseases. Isolation of exosomes is the first step in exosome-related research and its applications. Standard benchtop exosome separation and sensing techniques are tedious and challenging, as they require large sample volumes, multi-step operations that are complex and time-consuming, requiring cumbersome and expensive instruments. In contrast, microfluidic platforms have the potential to overcome some of these limitations, owing to their high-precision processing, ability to handle liquids at a microscale, and integrability with various functional units, such as mixers, actuators, reactors, separators, and sensors. These platforms can optimize the detection process on a single device, representing a robust and versatile technique for exosome separation and sensing to attain high purity and high recovery rates with a short processing time. Herein, we overview microfluidic strategies for exosome isolation based on their hydrodynamic properties, size filtration, acoustic fields, immunoaffinity, and dielectrophoretic properties. We focus especially on advances in label-free isolation of exosomes with active biological properties and intact morphological structures. Further, we introduce microfluidic techniques for the detection of exosomal proteins and RNAs with high sensitivity, high specificity, and low detection limits. We summarize the biomedical applications of exosome-mediated therapeutic delivery targeting cancer cells. To highlight the advantages of microfluidic platforms, conventional techniques are included for comparison. Future challenges and prospects of microfluidics towards exosome isolation applications are also discussed. Although the use of exosomes in clinical applications still faces biological, technical, regulatory, and market challenges, in the foreseeable future, recent developments in microfluidic technologies are expected to pave the way for tailoring exosome-related applications in precision medicine.

Development and Testing of a Block Hydrocyclone

The study aimed to theoretically substantiate the efficiency of liquid purification and obtain corroborating experimental data for a hydrocyclone, consisting of several blocks. Mathematical models of the process of hydrodynamic fluid filtration were developed with the use of screw swirlers. The obtained mathematical models characterize all the main processes of fluid movement in various zones of the functioning of the hydrocyclone. Formulas for calculating the structures of hydrocyclone blocks are included. A block for swirling the flow of the liquid to be cleaned has been made in the form of a three-way screw. For the first time, wear-resistant and high-strength plastic ZEDEX ZX-324 has been used as a material. An experimental study was conducted and the change in the Reynolds number and the coefficient of fluid consumption was shown, using different constructions of the three-way screw. The research results confirmed the correctness and sufficiency of mathematical models for the development and production of block hydrocyclones.

Thermohydrodynamic Studies of Vertical Wells in Non-Linear Filtration

In this paper the computational algorithm for interpreting the results of hydrodynamic and thermohydrodynamic studies in non-linear filtration is proposed. The algorithm allows to determine the conductivity of the reservoir, the limiting pressure gradient, reservoir pressure and the regularization parameter. Temperature and pressure changes data, measured on a vertical well, are taken as the initial information.

Two-phase flow in microfluidic-chip design of hydrodynamic filtration for cell particle sorting.

As one of the flow-based passive sorting, the hydrodynamic filtration using a microfluidic-chip has shown to effectively separate into different sizes of subpopulations from cell or particle suspensions. Its model framework involving two-phase Newtonian or generalized Newtonian fluid (GNF) was developed, by performing the complete analysis of laminar flow and complicated networks of main and multiple branch channels. To predict rigorously what occurs in flow fields, we estimated pressure drop, velocity profile, and the ratio of the flow fraction at each branch point, in which the analytical model was validated with numerical flow simulations. As a model fluid of the GNF, polysaccharide solution based on Carreau type was examined. The objective parameters aiming practical channel design include the number of the branches and the length of narrow section of each branch for arbitrary conditions. The flow fraction and the number of branches are distinctly affected by the viscosity ratio between feed and side flows. As the side flow becomes more viscous, the flow fraction increases but the number of branches decreases, which enables a compact chip designed with fewer branches being operated under the same throughput. Hence, our rational design analysis indicates the significance of constitutive properties of each stream.

Label-free microfluidic sorting of microparticles.

Massive growth of the microfluidics field has triggered numerous advances in focusing, separating, ordering, concentrating, and mixing of microparticles. Microfluidic systems capable of performing these functions are rapidly finding applications in industrial, environmental, and biomedical fields. Passive and label-free methods are one of the major categories of such systems that have received enormous attention owing to device operational simplicity and low costs. With new platforms continuously being proposed, our aim here is to provide an updated overview of the state of the art for passive label-free microparticle separation, with emphasis on performance and operational conditions. In addition to the now common separation approaches using Newtonian flows, such as deterministic lateral displacement, pinched flow fractionation, cross-flow filtration, hydrodynamic filtration, and inertial microfluidics, we also discuss separation approaches using non-Newtonian, viscoelastic flow. We then highlight the newly emerging approach based on shear-induced diffusion, which enables direct processing of complex samples such as untreated whole blood. Finally, we hope that an improved understanding of label-free passive sorting approaches can lead to sophisticated and useful platforms toward automation in industrial, environmental, and biomedical fields.

ФИЛЬТРАЦИЯ ЖИДКОСТЕЙ В АНОМАЛЬНЫХ КОЛЛЕКТОРАХ

Актуальность исследования обусловлена необходимостью разработки эксплуатационных объектов юрских и ачимовских отложений с низкими фильтрационными свойствами и залежей вязкопластичной нефти. Для исследования фильтрации флюидов в указанных коллекторах нельзя применять классический закон Дарси. Поэтому для прогнозирования технологических показателей разработки и расчёта добывных возможностей скважин следует учитывать возникающие особенности процессов фильтрации и вытеснения нефти. Цель: установление связи между параметром Лагранжа и начальным градиентом давления; определение значений параметра Лагранжа при нарушении пределов применимости закона Дарси; обоснование применения методов гидродинамического моделирования, разработанных для описания фильтрационных процессов вязкопластичной жидкости, к изучению движения флюидов в низкопроницаемых коллекторах. Объекты: высокопроницаемые коллектора, насыщенные высоковязкой (вязкопластичной) нефтью; низкопроницаемые пласты ачимовских и юрских отложений. Методы: интерпретация результатов лабораторных исследований керна; физическое моделирование фильтрационных процессов флюидов в аномальных коллекторах. Результаты. Отклонение от закона Дарси при фильтрации жидкостей в аномальных коллекторах определяется посредством вычисления значений параметра Лагранжа. Предложен способ определения нижней границы применимости закона Дарси, при нарушении которого для описания предлагаются две модели: с начальным градиентом давления и нелинейная модель. Для процессов фильтрации с нарушением верхнего предела применимости закона Дарси рассмотрена нелинейная модель. Приведены примеры определения параметра Лагранжа для случаев нарушения нижней и верхней границ закона Дарси. Для описания процессов фильтрации дилатантных и псевдопластических жидкостей вместо нелинейных уравнений предлагается использовать систему уравнений пьезопроводности. Показано, что методы решения гидродинамических задач фильтрации и вытеснения нефти, установленные для вязкопластичных нефтей, применимы и для низкопроницаемых коллекторов.

An analysis of bacteria separation and filtration from blood sample using passive methods

In the development of the biological device separation of bioparticles plays a vital role in the field of health care and diagnostics. One of the mechanism which satisfies the demands of precision, high throughput, less clogging problem and multiple bioparticle separation is Hydrodynamic Filtration (HDF) Technique uses fluid flow rates, arrays/grooves, streamlines and other related characteristics/parameters by utilizing a Colander/Strainer microchannel network. By using a commercial software COMSOL Multiphysics a proposed analysis and simulation for bioparticle separation through Colander/Strainer geometrical network were studied with a structure of slanted angles 15°, 25°, 35° and 90° in which a bioparticles were introduced via inlet systematically with definite fluid flow rates with addition of buffer. However the larger bioparticles (K. pneumoniae/mammalian cells) and smaller bioparticles (Blood cells) were been formulated (injected) depending on the individual flowrates in a system of microfluidics and its streamlines due to which smaller bioparticles were towed (dragged) with the streamlines directions and larger bioparticles were robust towards the upper sidewalls of a microchannel as per the flow rates as well as other parameters applied and the separation of targeted bioparticles were achieved in a precise manner through a desired outlets. A successful performance for Colander/strained microchannel network was achieved by simulation for separation of targeted bioparticles, specifically a design consisting of 25° and 90° Colander/strained structure provided a precise targeted bioparticle separation through outlet-4 and outlet-1 for larger bioparticles dependent on size and mass and other bioparticles through the different outlets available according to the parameters registered.