Recovery Of Particles Research Articles

Recycled from waste tires carbon black/high‐density polyethylene composite: Multi‐scale mechanical properties and polymer aging

AbstractThis study addresses the global issue of recycling vehicle rubbish tires by a vacuum pyrolysis process, exploring a novel environmentally responsive approach for thermal decomposition and recovery of the carbon black particles contained in tires (25–30 wt%). Carbon black is typically used for its UV protection in plastics and abrasion resistance in composites and rubbers. This research aims at providing an eco‐responsible alternative to commercial carbon black of fossil origin by recycling the carbon black (rCB) from end‐of‐life tires. A particle reinforced composite material was developed containing rCB and high‐density polyethylene. For comparison purposes, an identical composite was manufactured using commercial carbon black (CB). Accelerated aging studies have been carried out on the materials. Topographic evolution of the samples with aging and oxidation kinetic of the surface and through the thickness were studied. Multiscale mechanical properties have been evaluated for a more comprehensive understanding of the mechanisms involved in the degradation. A comparison of the different materials properties was carried out in order to highlight the various elements linked to the degradation and UV protection of materials. This work helps demonstrating the feasibility of using recycled carbon black particles from waste tires as a high‐performance filler for plastics and composites.Highlights Recycled carbon black (rCB) is an eco approach of revalorizing tire waste. Vacuum pyrolysis successfully allows recovery of reusable rCB. The rCB acts as a photon absorber, limiting degradation of HDPE. The rCB limits the cross‐linking responsible of embrittlement of HDPE. A critical carbonyl index of 20 marks the occurrence of cracks and degradation.

Design optimization of groundwater circulation well based on numerical simulation and machine learning

The optimal design of groundwater circulation wells (GCWs) is challenging. The key to purifying groundwater using this technique is its proficiency and productivity. However, traditional numerical simulation methods are limited by long modeling times, random optimization schemes, and optimization results that are not comprehensive. To address these issues, this study introduced an innovative approach for the optimal design of a GCW using machine learning methods. The FloPy package was used to create and implement the MODFLOW and MODPATH models. Subsequently, the formulated models were employed to calculate the characteristic indicators of the effectiveness of the GCW operation, including the radius of influence (R) and the ratio of particle recovery (Pr). A detailed collection of 3000 datasets, including measures of operational efficiency and key elements in machine learning, was meticulously compiled into documents through model execution. The optimization models were trained and evaluated using multiple linear regression (MLR), artificial neural networks (ANN), and support vector machines (SVM). The models produced by the three approaches exhibited notable correlations between anticipated outcomes and datasets. For the optimal design of circulating well parameters, machine learning methods not only improve the optimization speed, but also expand the scope of parameter optimization. Consequently, these models were applied to optimize the configuration of the GCW at a site in Xi’an. The optimal scheme for R (Q = 293.17 m3/d, a = 6.09 m, L = 7.28 m) and optimal scheme for Pr (Q = 300 m3/d, a = 3.64 m, L = 1 m) were obtained. The combination of numerical simulations and machine learning is an effective tool for optimizing and predicting the GCW remediation effect.

Quantifying Contributions of Different Repulsion to Film Drainage Time during the Bubble-Solid Surface Attachment and Implications for the Flotation of Fine Particles.

The flotation recovery of fine particles faces serious challenges due to the lack of kinetic energy required for supporting their radial displacement and attachment with bubbles. Generally, the hydrodynamic resistance and repulsive disjoining pressure successively inhibit the liquid outflow intervening between the bubble and solid surfaces. To quantitatively characterize the influence of the main repulsion on film thinning time, experiments have been designed in three different aqueous systems. Bubble surface mobility closely associated with hydrodynamic resistance was determined by the rising bubble technique, and the DLVO theory was employed to confirm the evolution of electrostatic repulsion. The film drainage process was then measured based on the high-speed microscopic interferometry. Furthermore, the influence of the main repulsion on bubble-solid surface interactions was examined by flotation recovery. Results show that the earlier buildup of hydrodynamic force ran through the whole film thinning process, and under immobile conditions, the central region gradually became dominant in film thinning due to the very limited fluid flow at the thinnest rim position. Therefore, to achieve the identical film thickness (∼100 nm), the large hydrodynamic resistance could prolong the film thinning time by about 1 order of magnitude, compared with that induced by electrostatic repulsion, which accounts for the increased flotation recovery by 10% using mobile bubbles. This study not only enhances the understanding of how typical repulsive forces work in film drainage dynamics but also opens up an avenue for enhancing flotation and avoiding wasting resources by modulating bubble surface mobility and thus micro/nanoscale fluid flow.

High throughput clogging free microfluidic particle filter by femtosecond laser micromachining.

In recent decades, driven by the needs of industry and medicine, researchers have been investigating how to remove carefully from the main flow microscopic particles or clusters of them. Among all the approaches proposed, crossflow filtration is one of the most attractive as it provides a non-destructive, label-free and in-flow sorting method. In general, the separation performance shows capture and separation efficiencies ranging from 70% up to 100%. However, the maximum flow rate achievable (µL/min) is still orders of magnitude away from those suitable for clinical or industrial applications mainly due to the low stiffness of the materials typically used. In this work, we propose an innovative hydrodynamic-crossflow hybrid filter geometry, buried in a fused silica substrate by means of the femtosecond laser irradiation followed by chemical etching technique. The material high stiffness combined with the accuracy of our manufacturing technique allows the 3D fabrication of non-deformable channels with higher aspect ratio posts, while keeping the overall device dimensions compact. The filter performance has been validated through experiments with both Newtonian (water-based solution of microbeads) and non-Newtonian fluids (blood), achieving separation efficiencies of up to 94% and large particles recovery rates of 100%, even at very high flow rates (mL/h).

Recovery and reuse of magnetic silica-coated iron oxide particles for eco-friendly chemical mechanical planarization

Chemical mechanical planarization (CMP), a crucial process in semiconductor manufacturing, raises environmental concerns due to increased waste generation, prompting questions about its long-term sustainability. To address this issue, we explore an innovative approach to the waste management and recycling process by introducing magnetite (Fe3O4) particles coated with SiO2 layers, aimed at enhancing the CMP recycling efficiency. These core-shell particles exhibit controlled shell thickness, and modified surface charges, as confirmed by various analytical techniques. Our results reveal that slurries containing Fe3O4@SiO2 particles significantly improve W removal rates and surface smoothness compared to conventional slurries, attributed to the optimal mechanical properties. Moreover, the magnetite core facilitates the magnetic separation and recovery of used particles from spent slurries, offering a cost-effective and environmentally friendly solution. The recycling efficacy of these particles is demonstrated through multiple CMP cycles, showing consistent removal rates and surface quality, highlighting the potential of magnetic separation in sustainable CMP.

Maximization of ultrafine poly-mineral ore sequential flotation recovery through synergistic effect of conventional and nano-size bubble combination

Nanobubble-containing water (NW) was applied to the flotation of lead and zinc minerals (D50 = 4 µm or D90 = 22 µm) to enhance the recovery of ultrafine valuable particles and prevent their loss to the tailings. Two separate bi-level factorial designs were implemented to optimize the NW portion (volume of necessary water for pulp preparation substituted with NW), potassium ethyl xanthate (PEX), potassium amyl xanthate (PAX), and frother dosage, to each discrete concentrate. Based on the statistical analysis results, frother dosage was the most influential parameter, where raising it from 25 to 50 g/t increased the recovery of lead and zinc by 12.25 and 3.34 %, respectively. The substitution of tap water (TW) with 100 % NW improves lead and zinc recovery by 7.46 % and 1.41 %, respectively. Based on the approved response surfaces, PEX = 160 g/t, NW = 100 %, and frother = 50 g/t minimize lead loss to the tailings (76.29 % recovery to concentrate), and PEX = 80 g/t, PAX = 39.75 g/t, NW = 79.82 %, and frother = 48.16 g/t minimize zinc loss to the tailings (94.27 % recovery to concentrate).

Thermodynamic stability of the meniscus oil film between air/solid/water and its relevance to flotation

The behavior of oil is an important aspect in the area of mineral flotation or oil-water separation. This paper proposes a specific phenomenon that a meniscus oil film may form between the air bubble and the solid surface under water surroundings. A thermodynamic system containing an air bubble, an oil droplet, a solid matrix, and water surroundings was constructed. The mechanical equilibrium state of the oil meniscus film was solved. The free energy difference ∆B between the oil film-formed state and a reference state based on the Gibbs surface thermodynamic theory is applied to characterize the stability of the meniscus oil film. The impacts of the oil-gas volume ratio and the interfacial tensions are taken into consideration. The results show that the equilibrium morphologies of the system are directly correlated with the interfacial tensions. A minimal ∆Bmin can be found at a certain volume ratio and the case ∆B<0 generally exists. It indicates the formation of oil film leads the system to a lower energy state which is thermodynamically stable. The batch flotation using glass beads and n-alkane collectors was conducted. The flotation results show that the oil can improve the particle recovery and the results can be well interpreted by the mechanism correlated to meniscus oil film.

Detection of SARS-CoV-2 in Wastewater Associated with Scientific Stations in Antarctica and Possible Risk for Wildlife.

Before December 2020, Antarctica had remained free of COVID-19 cases. The main concern during the pandemic was the limited health facilities available at Antarctic stations to deal with the disease as well as the potential impact of SARS-CoV-2 on Antarctic wildlife through reverse zoonosis. In December 2020, 60 cases emerged in Chilean Antarctic stations, disrupting the summer campaign with ongoing isolation needs. The SARS-CoV-2 RNA was detected in the wastewater of several scientific stations. In Antarctica, treated wastewater is discharged directly into the seawater. No studies currently address the recovery of infectious virus particles from treated wastewater, but their presence raises the risk of infecting wildlife and initiating new replication cycles. This study highlights the initial virus detection in wastewater from Antarctic stations, identifying viral RNA via RT-qPCR targeting various genomic regions. The virus's RNA was found in effluent from two wastewater plants at Maxwell Bay and O'Higgins Station on King George Island and the Antarctic Peninsula, respectively. This study explores the potential for the reverse zoonotic transmission of SARS-CoV-2 from humans to Antarctic wildlife due to the direct release of viral particles into seawater. The implications of such transmission underscore the need for continued vigilance and research.

Recovery of biochar particles laden with lead in saturated porous media by DC electric field

The co-transport behavior of environmental pollutants with biochar particles has aroused great interests from researchers due to the concerns about pollutant diffusion and environmental exposure after biochar is applied to soil. In this work, the recovery and co-transport behavior of biochar micron-/nano-particles (BCMP and BCNP) and lead (Pb2+) in saturated porous media were investigated under different ionic strength conditions (IS = 1, 5 and 10 mM) under a direct current electric field. The results showed that the electric field could significantly enhance the mobility of Pb adsorbed biochar particles, particularly BCNP. The recovery of Pb laden biochar particles was improved by 1.8 folds, reaching 78.8% at maximum under favorable condition at +0.5 V cm−1. According to the CDE (Convection-Dispersion-Equation) model and DLVO (Derjaguin-Landau-Verwey-Overbeek) theory analysis, the electric field facilitated the transport of Pb carried biochar mainly by increasing the negative charges on biochar surface and improving the repulsive force between biochar and porous media. High IS was favorable for biochar transport under the electric field, but inhibited desorbing Pb2+ from biochar (18% by maximum at IS = 10 mM). By switching the electric field power, a two-stage strategy was established to maximize the recovery of both biochar particles and Pb, where BCNP and Pb recovery were higher than electric field free case by 90% and 35%, respectively. The findings of this study can help build a biochar recovery approach to prevent potential risks from biochar application in heavy metal contaminated soil remediation.

Phase reconstruction and singularity recovery of submicron particles in far-field phase space data using deep learning networks

Phase images often contain more comprehensive information compared to amplitude images. The precise visualization of phase images generated from light scattering by submicron particles is paramount for investigating the underlying scattering mechanisms and exploring applications centered around these submicron particles. This study showcases the efficacy of neural networks in acquiring the capacity to conduct phase reconstruction and recover singularities through appropriate training. Our deep learning-based approach introduces an entirely novel framework for phase recovery, accomplished by learning the distribution of scattered light fields from submicron particles, as obtained through a polarized indirect microscopic imaging (PIMI) system, within a custom Poincaré sphere (phase space). We validate this method by successfully reconstructing phase images of polystyrene (PS) balls with varying radii, and comparing diverse network structures and data flows in the process. Furthermore, we substantiate our experimental results by corroborating them with finite difference time domain (FDTD) simulations. These findings underscore the remarkable regularity within the distribution of phase space data, opening up new avenues for advancing the study of nanostructures.

Sampling, composition, and biological effects of Mexico City airborne particulate matter from multiple periods

Air pollution is a worldwide environmental problem with an impact on human health. Particulate matter of ten micrometers or less aerodynamic diameter (PM10) as well as its fine fraction (PM2.5) is related to multiple pulmonary diseases. The impact of air pollution in Mexico City, and importantly, particulate matter has been studied and considered as a risk factor for two decades ago. Previous studies have reported the composition of Mexico City particulate matter, as well as the biological effects induced by this material. However, material collected and used in previous studies is a limited resource, and sampling and particle recovery techniques have been improved. In this study, we describe the methods used in our laboratory for Mexico City airborne particulate matter PM10 and PM2.5 sampling, considering the years 2017, 2018 and 2019. We also analyzed the PM10 and PM2.5 samples obtained to determine their composition. Finally, we exposed lung cell line cultures to PM10 and PM2.5 to evaluate the biological effect of the material in terms of cell viability, cell death, inflammatory response, and cytogenetic alterations. Our results showed that PM10 composition includes inorganic, organic and biological compounds, while PM2.5 is a mixture of more enriched organic compounds. PM10 and PM2.5 treatment in lung cells does not significantly impact cell viability/cell death. However, PM10 and PM2.5 increase the secretion levels of IL-6. Moreover, PM10 as well as PM2.5 induce cytogenetic alterations, such as micronuclei, anaphase bridges, trinucleated cells and apoptotic cells in lung cells. Our results update the evidence of the composition and biological effects of Mexico City particulate matter and provide us a reliable basis for future approaches.

Enhanced coarse coal slime separation in a gravity–flotation coupled separator with up-flow feeding and dual-concentrate

ABSTRACT A gravity – flotation coupled separator with up-flow feeding and dual-concentrate was developed to improve the recovery and selectivity in coarse coal slime separation. The separator combines flotation, cyclone separation, and gravity sedimentation. The optimal separation performance was achieved under the following conditions: slurry concentration = 100 g/L, feed flow rate = 4.411 m3/h, circulating rate = 3.125 m3/h, fifigfeeding air flow rate = 2 m3/h, frother dosage = 150 g/t and collector dosage = 1500 g/t. Two concentrates were obtained with ash contents of 7.48% and 11.56%. The partition coefficients of the 0.75–1 and 0.5–0.75 mm fractions were 88.42% and 95.92%, respectively, indicating the satisfactory recovery of coarse particles. The ash content in the tailings was 66.08%, indicating good selectivity. The diverging flow under the froth layer produced a coarse concentrate, which improved the recovery of the concentrate and reduced the flotation concentrate ash content. The total recovery of the concentrate blended with the + 0.25 mm fraction of diverging flow was 84.00%. Both up-flow and cyclone separation are beneficial for coarse particle recovery. The static separation cone is instrumental in improving the separation effect. Therefore, this wide-sized coal-slime separator facilitates the effective separation of both coarse and fine particles.

The effect of particle geometry (size & shape) on the recovery of gold and copper metallic particles from end-of-life random access memory cards by flotation

Since Random Access Memory (RAM), one of the main parts of computers contains a remarkable quantity of precious metals, applying flotation at the pre-concentration stage to recycle these metals can result in a more cost-effective, user-friendly, and environmentally friendly process compared to direct chemical methods. While the significance of physical characteristics like particle size and shape in the flotation process is well established, the impact of particle shape in the flotation process utilized in the recycling of end-of-life (EoL) RAMs hasn’t yet been thoroughly investigated. To fill this gap, a two-stage coarse flotation approach is used for the selective recovery of plastic and valuable metallic particles for sustainable development. The particle geometry of metallic particles recovered by flotation was characterized by axis measurement on the images by optical microscope that allows us to distinguish particles of different sizes and colors that make up the sample and evaluated in terms of particle size distribution (PSD), elongation (E) and roundness (R) parameters. The results showed that after the plastic fraction is effectively removed, it is possible to produce pre-concentrated products with high metal content (more than 50 % Cu content at the 1st stage and 1800 g/t Au content at the 2nd stage using 900 g/t KAX) in an economical and environmentally friendly way. Thus, it was concluded that the gold and copper metallic particles in the reduced-size EoL RAM cards could be easily floated by attaching them to the air bubble with the help of the collector, thanks to their flat shape.

Ultrasound Pretreatment for Enhancing Fine and Ultrafine Flake Graphite Flotation Beneficiation.

With the severe depletion of coarse flake graphite (a critical raw material) resources, developing and utilizing fine and ultrafine graphite resources have recently attracted attention. Froth flotation is a widely used technique for the initial enrichment of graphite; however, the flotation selectivity decreases significantly along with particle size reduction. Ultrasound pretreatment would be a promising method to improve the flotation of fine particles. As an innovative approach to understand better the flotation response of different flake graphite sizes, this study conducted a comparative analysis based on flotation concentrate yield and ash as well as ash removal rate between the flake graphite with various particle sizes after ultrasound pretreatment. Particle size, X-ray powder diffraction, and scanning electron microscopy and energy dispersive X-ray spectroscopy analyses were used to investigate the effect of ultrasound treatment on mineralogical properties of the flake graphite with varied particle sizes. Process outcomes indicated that the flotation performance of fine flake graphite (mean chord length: 62.63 μm) was significantly enhanced after ultrasound pretreatment. However, flotation of the ultrafine flake graphite (mean chord length: 24.97 μm) after ultrasound treatment was limited due to the difficulty of generating sufficient fragmentation and dissociation by microjets and shock waves formed by the cavitation effect. Compared with conventional flotation, the concentrate yield of ultrasound flotation increased from 88.95 to 94.98%, ash content decreased from 5.72 to 4.87%, and ash removal rate enhanced from 36.94 to 42.61%. Particle size and mineral property analyses confirmed that further crushing and dissociation of the larger flake graphite after ultrasound pretreatment would be the main factors contributing to improved flotation performance. Additionally, the formation of air flocs in the coarse flake graphite during the ultrasound pretreatment process facilitated the flotation recovery of the crushed graphite particles.

Environmental compliance assessment for the desulfurization of sulfide mine waste tailings: A case study of Ok Tedi Mine, Papua New Guinea

The effective management of sulfide mine waste tailings is a complex task because of the potential for acid rock drainage to harm aquatic ecosystems. Although previous research has explored the environmental consequences of sulfide mine waste tailings and the potential advantages of desulfurization method, there is a lack of studies examining the environmental compliance of desulfurization efforts. To bridge this knowledge gap, a study was conducted at the Ok Ted Mine to evaluate the environmental compliance of the implemented desulfurization process. Ninety samples of sulfide tailing, desulfurized tailing, and sulfide concentrate were collected and analyzed for geochemical and physical properties. The acid-generating capacities were assessed using the Sobek's static test, whereas the particle size, pH, and recovery were evaluated for the overall performance of the desulfurization process. These findings indicated that the desulfurization process significantly reduced the acid-generating capacity and heavy metal concentrations of the sulfide tailings below the regulatory threshold levels. Therefore, the desulfurization approach employed at the Ok Ted Mine comply with the environmental regulaotry requirments. For further assessment, a study is recommended to evaluate the impact of desulfurization on the ecosystem to predict full extent of biodiversity recovery after mine life.

Experimental study on the aluminum aggregate property during the treatment of lightweight oil spills using electrocoagulation

ABSTRACT The properties of aggregates significantly affect the demulsification efficiency within the electrocoagulation reactor. This paper aims to explore aggregate properties including the particle size, strength factor (Fs), and recovery factor (Fr). The experiments were carried out using aluminum-aluminum electrodes. The experimental results indicate that breakage time did not change Fs much but was positively correlated with Fr. When the current was increased from 0.75 A to 1.0 A, Fs experienced a decrease of 12.42%, while Fr exhibited an increase of 19.38%. In comparison to pH 9.0, both Fs and Fr demonstrated an increase at pH levels of 2.0 and 10.0. The size of aggregates significantly decreases under rocking conditions simulating offshore environments, while the oil removal rate does not change much. This phenomenon can be attributed to the fact that different initial mean particle sizes have different Fs and Fr. The aggregates |Fs-Fr| were positively correlated with the initial average particle size of the electroflocculated aggregates. The present study offers a crucial theoretical foundation for the growth and regulation of aggregates formed during electrocoagulation treatment of oil spills on the sea surface. Synopsis: This paper is of great theoretical value for understanding the growth and control of EC aggregates to treat offshore light oil spills using the electrocoagulation process.

Magnetic capture device for large volume sample analysis.

Immunomagnetic separation (IMS) techniques employing superparamagnetic particles can successfully isolate various components from mixtures. However, their utility can be limited for large-volume samples, viscous samples, or those containing a high density of particulate matter because of the need to generate high field gradients for particle recovery. Therefore, a new class of immunomagnetic particles was devised utilizing a single, macroscopic Pyrex spinbar conjugated with biorecognition elements to address these limitations. Advantages include an inherent capacity for effective mixing, an almost instantaneous recovery of the spinbar that can be performed without expensive equipment and with no loss of magnetic particles during processing, and reduced transfer of sample matrix. As a result, spinbars can provide an effective means for IMS with large-volume assays composed of complex matrices.

An environmentally friendly method for selective recovery of silver and ITO particles from flexible CIGS solar cells

While the share of solar energy harvesting by photovoltaic (PV) systems in electricity production increases, their recycling still remains mainly at an early stage. Therefore, valuable and critical elements like silver (Ag) and indium (In) are lost along with production and end-of-life waste, highlighting the need for simple and sustainable recycling solutions which could be easily implemented by the industry. In this paper, we suggest a simple environmentally friendly method for selective recovery of Ag and Indium Tin Oxide (ITO) particles from flexible Copper Indium Gallium diSelenide (CIGS) solar cells, using two-step ultrasonic (US) leaching with low nitric acid (HNO3) concentration of 0.1 M. The first step aimed at the selective liberation of ITO through the selective dissolution of the zinc-rich layer underneath, using low US power for 3 min. In the second step, the same conditions as in the first step were applied, but now using high US power for 15 min for removal of the Ag grid lines. Both the ITO and the Ag grid particles were subsequently recovered by filtration and there was no loss of Ag observed in the leachates. By this method, a complete separation of ITO and Ag from the solar cell was achieved, with no changes in their crystal structure and promising purities of about 70.5 wt% and 95.0 wt%, respectively. This new approach opens up a new path for possible direct reuse of these materials in the manufacturing of new PVs, after further purification, with an impressively low need for chemicals.

Modern pollen dispersal in relation to present vegetation distribution and land use in the Baspa valley, Kinnaur, western Himalayas.

Interpretation of a fossil pollen data for the vegetation and climate reconstruction of any region needs a modern pollen-vegetation analogue for its calibration. We analyzed the surface sediments and moss polsters for the pollen and microcharcoal records to understand the modern pollen-vegetation relationship and human activities in the Baspa Valley, Kinnaur, Himachal Pradesh. Presently, valley is occupied by the arboreal and non-arboreal vegetation of temperate to subalpine habitats and land use activities. The recovered pollen assemblages showed variability in the dispersal behavior of pollen of taxa growing along the valley transect and also captured the signals of human activities over land use. The overall dominance of arboreal pollen in the recovered pollen assemblage corresponds with the dominant growth of conifers and broadleaf tree taxa and represents the valley vegetation at a regional scale. However, the profuse pollen production of a few arboreal taxa and long distance pollen transport from one vegetation zone to other by the strong upthermic valley winds could bias the pollen representation of in-situ vegetation. The high pollen frequency of non-arboreal taxa in the open meadows represents the near vicinity to their plant source. Human activities like fire burning and cultivation by the local population are evident by the recovery of microcharcoal particles and pollen of plants belonging to Cerealia Poaceae, Asteraceae, Amaranthaceae, Polygonaceae, Rosaceae, Juglandaceae, etc. The dataset taken as modern pollen-vegetation analogue is useful to assess past changes in the vegetation and land cover in relation to climate and human factors for future sustenance.

Assessment of the efficiency of virus extraction from food matrices and the frequency of occurrence of contaminated products in the retail network

Express detection of viruses, in particular, norovirus (NoV) and hepatitis A virus (HAV), is becoming an extremely important task for food safety control. This study examines various approaches to recovery of viral particles and methods for RNA extraction from food matrices to assess mengovirus extraction efficiency. Efficiency of mengovirus extraction from raspberry was 14.26%, from oysters 7.99%, from pork liver 8.33%. Assessment of RNA extraction by various methods was carried out. The highest efficiency of mengovirus extraction from pork liver (19.37%) was observed when RNA was extracted using the eGene-up semi-automatic system. The lowest extraction efficiency (5.31%) was achieved upon manual RNA extraction. When RNA was extracted from oysters, the maximum efficiency (33.35%) was ensured by the AutoPure nucleic acid extraction station and NucliSens kit, while the minimum efficiency (9.78%) was observed when using the eGene-up system. The performed monitoring of food products showed that the highest occurrence of norovirus GII was recorded in oyster samples (9.6% of tested samples); the second place was occupied by strawberry, where occurrence of norovirus GII was 6.8%. In the raspberry samples, norovirus GII was not detected.