Publikační činnost Katedry bezpečnosti práce a procesů / Publications of Department of Occupational and Process Safety (040)

Permanent URI for this collectionhttp://hdl.handle.net/10084/64804

Kolekce obsahuje bibliografické záznamy publikační činnosti (článků) akademických pracovníků Katedry bezpečnosti práce a procesů (040) v časopisech a v Lecture Notes in Computer Science registrovaných ve Web of Science od roku 2003 po současnost.
Do kolekce jsou zařazeny:
a) publikace, u nichž je v originálních dokumentech jako působiště autora (adresa) uvedena Vysoká škola báňská-Technická univerzita Ostrava (VŠB-TUO),
b) publikace, u nichž v originálních dokumentech není v adrese VŠB-TUO uvedena, ale autoři prokazatelně v době jejich zpracování a uveřejnění působili na VŠB-TUO.

Bibliografické záznamy byly původně vytvořeny v kolekci Publikační činnost akademických pracovníků VŠB-TUO, která sleduje publikování akademických pracovníků od roku 1990.

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Now showing 1 - 20 out of 53 results

Gas in scattering media absorption spectroscopy for time-resolved characterization of gas diffusion processes in porous materials
(Elsevier, 2024) Dostál, Michal; Suchánek, Jan; Bitala, Petr; Klečka, Vít; Nevrlý, Václav; Klímková, Lenka; Konečný, Petr; Vořechovská, Dita; Kubát, Pavel; Zelinger, Zdeněk
Signal denoising is a serious problem for in-situ laser diagnostics of gases dispersed in porous materials. An optical sensor system based on absorption spectroscopy of gases in a scattering environment was built using a 3D printed cell with reference samples of polystyrene foam. Selected A-band spectral lines of molecular oxygen were investigated using wavelength modulated spectroscopy with second harmonic detection. Quantitative information on the concentration of analyte dispersed in the porous medium was obtained at extremely low signal-to-noise ratio (SNR < 10). A spectral line shape fitting procedure based on the Gabor transform followed by a filtered inverse fast Fourier transform allowed to achieve a relatively high SNR with good linearity over a range of reduced oxygen concentrations in air. Finally, the applicability of the optical sensor system to monitor the diffusion of carbon dioxide into air dispersed in a Styrofoam sample and vice versa was successfully demonstrated.
A new generation of fully-printed electrochemical sensors based on biochar/ethylcellulose-modified carbon electrodes: Fabrication, characterization and practical applications
(Elsevier, 2024) Gemeiner, Pavol; Sarakhman, Olha; Hatala, Michal; Ház, Aleš; Roupcová, Petra; Mackuľak, Tomáš; Barek, Jiří; Švorc, Ľubomír
Biochar is a material prepared by biomass pyrolysis, representing a more sustainable and efficient alternative to commonly used conventional carbon materials in electroanalysis. The aim of this paper is to point out that it can also show significant potential in the mass screen-printing production of miniaturized, low-cost, disposable and sensitive electrochemical sensors. Herein, a new generation of fully screen-printed electrochemical sensors is introduced, based on biochar/ethylcellulose-modified carbon working electrodes. The optimization in the sensor fabrication, involving the variability in the concentration of a binder and rheology modifier (ethylcellulose) and its impact on biochar inks from the viewpoint of viscoelasticity, printability and thermal stability, was performed to obtain the carbon-based electrochemical sensors with favourable robustness. The viability of these electrochemical sensors was demonstrated by the development and full validation of a new and sensitive differential pulse voltammetric method for the fast and reliable determination of paracetamol in pharmaceutical formulations. Within the method development, all necessary aspects, such as a study of the effect of ethylcellulose concentration, pH study of supporting electrolyte, selection of pulse parameters and analytical performance, were investigated. The obtained results allow us to predict the production and subsequent use of new, printable, cheap and environmentally friendly sensor platforms, which will exhibit convenient analytical performance with the possibility of commercialization.
Parameters affecting the explosion characteristics of hybrid mixtures arising from the use of alternative energy sources
(MDPI, 2024) Helegda, Matouš; Pokorný, Jiří; Helegda, Iris; Skřínský, Jan; Sinay, Juraj
Explosions of hybrid mixtures are an interesting theoretical and experimental problem in explosion sciences, because they combine the physicochemical properties of flammable gases and dusts. A hybrid mixture is composed of at least two substances in two or more states. The influence of the common presence of flammable gas on the explosiveness parameters of the combustible dust itself is proven. In this study, we present the effect of higher initiation temperatures, different initial sources of initiation with different energies, and the effect of the volume of explosion chambers on the explosions of hybrid mixtures arising from the use of alternative energy sources. The experiments were carried out in 20 L and 1.00 m3 explosion chambers (according to EN 14034-1+A1:2011–EN 14034-4+A1:2011). The accredited method of the Energy Research Centre, VSB-TU Ostrava, for tests was used. The goal is to approximate the behaviour of these systems under different initiation conditions so that it is possible to avoid excessively conservative or overly optimistic results, which then affect the determination of explosion parameters for practical use. It was found that the volume of the explosion chambers in combination with the used initiation source has a fundamental influence on the course of the explosion characteristics.
European round robin on safety characteristics of hybrid mixtures from vapors and dusts
(Elsevier, 2024) Heilmann, Vanessa; Spitzer, S.; Dufaud, Olivier; Hohenberger, M.; Jankůj, Vojtěch; Prodan, M.; Zakel, S.
As part of the development of a new standard testing procedure, a round robin study was conducted by six participating laboratories. This study involved the measurement of both the maximum explosion pressure and the maximum rate of pressure rise for hybrid mixtures comprising dust and vapor. Measurements were performed using a modified 20L-sphere. The primary objective of this collaborative effort was to assess the accuracy, reliability, and consistency of analytical and measurement methods across multiple laboratories, thereby increasing confidence in the obtained results. The method and protocol were developed as part of the NEX-HYS project and documented in a technical specification by the German Institute for Standardization Registered Association (DIN). The study revealed that precise pre-ignition pressure rise (PIPR) measurements and the use of a leak-free test apparatus significantly influenced the results of the measured maximum explosion pressure and maximum pressure rise rate.
Chemometrics approach to Cantilever enhanced photoacoustic spectroscopy with Quantum Cascade lasers
(Elsevier, 2024) Suchánek, Jan; Dostál, Michal; Nevrlý, Václav; Kubát, Pavel; Chaloupecká, Hana; Zelinger, Zdeněk
Cantilever-enhanced Photoacoustic Spectroscopy in combination with Wavelength Modulation Spectroscopy was used for the multicomponent analysis of gases. Distributed feedback Quantum Cascade Laser tunable in the region of similar to 1045 - 1048 cm(-1) was used as the excitation source. Principal component analysis (PCA) and Partial Least Squares (PLS) (the pls package in the statistical software R) methods were applied to a mixture of selected substances (methanol and ethanol) in the gas phase to both simulated (www.spectraplot.com) and experimentally acquired spectra, PCA predicting the number of substances and PLS its concentrations.
Simplified numerical model for determining load-bearing capacity of steel-wire ropes
(MDPI, 2023) Hronček, Juraj; Maršálek, Pavel; Rybanský, David; Šotola, Martin; Drahorád, Lukáš; Lesňák, Michal; Fusek, Martin
Steel-wire rope is a mechanical component that has versatile uses and on which human lives depend. One of the basic parameters that serve to describe the rope is its load-bearing capacity. The static load-bearing capacity is a mechanical property characterized by the limit static force that the rope is able to endure before it breaks. This value depends mainly on the cross-section and the material of the rope. The load-bearing capacity of the entire rope is obtained in tensile experimental tests. This method is expensive and sometimes unavailable due to the load limit of testing machines. At present, another common method uses numerical modeling to simulate an experimental test and evaluates the load-bearing capacity. The finite element method is used to describe the numerical model. The general procedure for solving engineering tasks of load-bearing capacity is by using the volume (3D) elements of a finite element mesh. The computational complexity of such a non-linear task is high. Due to the usability of the method and its implementation in practice, it is necessary to simplify the model and reduce the calculation time. Therefore, this article deals with the creation of a static numerical model which can evaluate the load-bearing capacity of steel ropes in a short time without compromising accuracy. The proposed model describes wires using beam elements instead of volume elements. The output of modeling is the response of each rope to its displacement and the evaluation of plastic strains in the ropes at selected load levels. In this article, a simplified numerical model is designed and applied to two constructions of steel ropes, namely the single strand rope 1 × 37 and multi-strand rope 6 × 7-WSC.
Toxicity testing of nonwovens used for production of respiratory protective equipment
(Státní zdravotní ústav, 2023) Kubátová, Hana; Roupcová, Petra; Klouda, Karel; Bátrlová, Kateřina
Objectives: During the covid-19 pandemic, protective equipment such as respirators and masks were widely used to protect respiratory tract. This disposable protective equipment is usually made from plastic fibre-based nonwoven fabrics. If used masks and respirators are improperly discarded, they pollute the environment by becoming a source of micro and nanoplastics. The aim of the study was to find out how stable the materials of protective equipment are and how released nano and microplastics can affect aquatic and soil organisms. Materials: The input materials used to produce respirators and masks were tested for their thermal stability and resistance to the release of plastic particles into the environment. To determine the thermal stability of the materials, a simultaneous thermal analysis - thermogravimetry (TGA) and differential scanning calorimetry (DSC) were performed. Results: Materials of masks and respirators are stable at temperatures common to temperate climate zone. However, the possible effects of chemical reactions of the materials with the environment were not considered during the measurement. The materials were also subjected to ecotoxicity tests according to European standards. Conclusion: While the leachate obtained by shaking the materials in water did not show acute toxicity to the selected aquatic organisms, the material itself had a significant effect on selected soil organisms (springtails).
1st international round robin test on safety characteristics of hybrid mixtures
(Elsevier, 2023) Spitzer, Stefan H.; Askar, Enis; Benke, Alexander; Cloney, Chris; D'Hyon, Sebastian; Dufaud, Olivier; Dyduch, Zdzislaw; Gabel, Dieter; Geoerg, Paul; Heilmann, Vanessa; Jankůj, Vojtěch; Jian, Wang; Krause, Ulrich; Krietsch, Arne; Mynarz, Miroslav; Norman, Frederik; Skřínský, Jan; Taveau, Jerome; Vignes, Alexis; Zakel, Sabine; Zhong, Shengjun
There is no applicable existing standard for the determination of safety characteristics for hybrid mixtures. While developing a new standard in a joint research project in Germany first results from parameter studies led to a standard procedure that can be adopted by laboratories that are already testing dusts in the so called 20L-sphere with as little additional effort as necessary. In fact, one of the main objectives of this research project was to keep modifications and adjustments from the generally accepted dust testing procedures as easy and minimal as possible so as to limit potential deviations from one laboratory to another.In this first round robin test on hybrid mixtures ever, with methane as gas component and a specific corn starch as dust sample, the practicality of the whole procedure, the scattering of the results and the deviation between the testing apparatuses is investigated. This paper summarizes the experimental procedure adopted and objectives of the first round-robin phase involving three of the four original German companies, plus volunteering laboratories from Australia, Belgium, Czech Republic, France, Poland and P.R. China. The results will have an impact on the new standard and may lead to robust data for later simulation purposes.
Behavior of polyethylene dust in large-scale vessels with pipes near the explosion
(Springer Nature, 2022) Sklenárová, Martina; Štroch, Petr; Bernatík, Aleš
The aim of the article is to point out the dangers arising from the properties of plastic dust and what influence its properties have on the origin and course of the explosion. The present study deals with a sample of polyethylene dust, by-product of granulate production and storage. The explosion tests are performed on containers of a similar shape to those found in plants. The volumes of the closed vessels are 1.35 m(3) (N1) and 5.45 m(3) (N2). The tests are conducted in vessel N1 with a venting area DN 250 on the top of the vessel, in vessel N2 with a venting area DN 585 or DN 775 installed on the upper flanges of the vessels, and in vessels interconnected by pipes with a diameter DN 150 and length of 3, 6, and 10 m. The experiments show that the pressure of the explosion in technological equipment may reach higher values than those obtained in laboratory tests. During the explosion propagation in the connected vessels, the effect of overpressure appears due to precompression; as a result, the measured pressure and the rate of pressure rise are many times higher than the values measured only in the vessel itself with a venting area. As the explosion propagates from a larger volume vessel to a smaller volume vessel, the effect of precompression of the mixture increases the explosion parameters in the smaller vessel despite the opening areas of both vessels. Other elements can be also used to ensure sufficient explosion protection. The results also describe the effect of the length of the pipeline route by which the vessels are connected.
Electrochemical characterization of leached steel-making sludge
(Springer Nature, 2022) Langová, Šárka; Kostura, Bruno; Raška, Pavel; Matýsek, Dalibor; Novák, Vlastimil; Ritz, Michal; Krčmář, Jiří
In this work, the electrochemical properties of the leached sludge, magnetite and zinc ferrite were studied. Acetic acid was used as a leaching reagent because, in recent years, there has been a surge of interest in using zinc-containing materials as photocatalysts, with acetic acid finding application in their preparation. Various methodological approaches were used, but the best results were achieved with a combination of 1-3 h leaching in 0.01 M acetic acid with a solid/liquid ratio of 500. In this arrangement, zincite was almost completely removed from the sludge, while zinc ferrite and magnetite remained in the solid residue. Ex situ analyses of the main leaching products were performed by X-ray diffraction, infrared spectroscopy, and thermogravimetry. The electrochemical behaviour of solid residue and model systems, that are micromagnetite and zinc ferrite, was studied in alkaline media by means of modified carbon paste electrodes, cyclic voltammetry, and chronocoulometry, with a suitable potential window ranging from 0 to 1.5 V. In summary, a linear dependence of the anodic and cathodic peak height on the square root of the scan rate was found. The position of the anodic and cathodic peaks shifted slightly with scan rate, only at low rates, up to 25 mV/s, the individual peaks coincided. The electrochemical response suggested a quasireversible process.
Experimental investigation of the consequences of acetylene pressure cylinder failure under fire conditions
(Elsevier, 2022) Jankůj, Vojtěch; Mynarz, Miroslav; Krietsch, Arne; Spitzer, Stefan H.; Lepík, Petr
Acetylene pressure cylinders are widely used in the industrial sector for welding, flame cutting, or heating. Sometimes during work, not only with acetylene cylinders, fires occur and in this case the risk of destruction increases and the behavior of such an exposed cylinder is unpredictable. The purpose of this study is to identify those critical conditions when acetylene cylinders burst and explode in fires. In the present study, acetylene cylinders were exposed to fire conditions. For this purpose, a woodpile as a source of fire was chosen, tested, and evaluated. In addition to the fire condition, this option guaranteed reproducibility and similar conditions for all tests. The individual cylinders were equipped with thermocouples measuring the shell temperature, and half of them were prepared in order to measure the temperatures inside the cylinder. An important factor was the measurement of the amount of pressure that was achieved during the destruction of the cylinder. For this purpose, a pressure transducer was attached to the outlet of the cylinder valve. Exposed to direct fire, they can explode in 10 min, which was confirmed. The critical pressure of 40 bar has been reached in 6 min, followed by destruction after 7 min in fire. Cylinders with internal thermocouples were destroyed when lower pressure was achieved. This confirms the fact that any change of the pressure cylinder affects the original properties. After the tests, the fragments of the selected cylinders were subjected to material tests. The results obtained in these tests are the main source of information for understanding the behavior of acetylene cylinders in fire and the possi-bility of increasing the safety of intervening rescue services in an emergency.
Extremity compartment syndrome: A review with a focus on non-invasive methods of diagnosis
(Frontiers Media S.A., 2022) Novák, Martin; Penhaker, Marek; Raška, Pavel; Pleva, Leopold; Schmidt, Martin
The article deals with an overview of acute extremity compartment syndrome with a focus on the option of non-invasive detection of the syndrome. Acute extremity compartment syndrome (ECS) is an urgent complication that occurs most often in fractures or high-energy injuries. There is still no reliable method for detecting ECS. The only objective measurement method used in clinical practice is an invasive measurement of intramuscular pressure (IMP). The purpose of this paper is to summarize the current state of research into non-invasive measurement methods that could allow simple and reliable continuous monitoring of patients at risk of developing ECS. Clinical trials are currently underway to verify the suitability of the most studied method, near-infrared spectroscopy (NIRS), which is a method for measuring the local oxygenation of muscle compartments. Less explored methods include the use of ultrasound, ultrasound elastography, bioimpedance measurements, and quantitative tissue hardness measurements. Finding a suitable method for continuous non-invasive monitoring of the syndrome would greatly improve the quality of care for patients at risk. ECS must be diagnosed quickly and accurately to prevent irreversible tissue damage that can occur within hours of syndrome onset and may even warrant amputation if neglected.
The determination of cystatin C in biological samples via the surface plasmon resonance method
(Future Science Ltd, 2021) Lesňák, Michal; Jursa, Dominik; Miškay, Marek; Riedlová, Helena; Barčová, Karla; Adámek, Milan
Surface plasmon resonance imaging biosensors have a number of advantages that make them superior to other analytical methods. These include the possibility of label-free detection, speed and high sensitivity to low protein concentrations. The aim of this study was to create and analyze biochips, with the help of which it is possible to test cystatin C in patient urine samples and compare the results with the one-time traditional ELISA method. The main advantage of the surface plasmon resonance imaging method is the possibility of repeated measurements over a long period of time in accordance with clinical practice. The surface of the biochip was spotted with anticystatin C and a negative control of mouse IgG at a ratio of 1:1. The aforementioned biochip was first verified using standard tests and then with patient samples, which clearly confirmed the required sensitivity even for very low concentrations of cystatin C. METHOD SUMMARY Surface plasmon resonance is a sensitive optical method that uses the generation of electromagnetic waves (plasmons) for detection. The propagation of surface plasmons at the metal-dielectric interface is very sensitive to changes in the refractive index, which allows for the monitoring of substance properties very close to the interface. The main advantage of the sensor over other currently used techniques is the possibility of label-free analysis and real-time analysis, with high sensitivity and specificity of the optical method.
Nanotextiles - materials suitable for respiratory tract protection but a source of nano- and microplastic particles in the environment
(Sciendo, 2022) Roupcová, Petra; Kubátová, Hana; Bátrlová, Kateřina; Klouda, Karel
The paper deals with the formation of nanomaterials (nanoparticles and nanofibers) in the manufacture and use of respiratory protective equipment. It focuses mainly on processes leading to the release of nanoplastics into the workplace and the environment. Based on selected properties of materials used for the manufacture of protective equipment, their stability in the environment is revealed. The paper demonstrates the impact on the environment considering semichronic phytotoxicity of nanoplastics.
Uncontrolled and controlled destruction of acetylene pressure cylinders
(MDPI, 2022) Jankůj, Vojtěch; Mynarz, Miroslav; Lepík, Petr
The risk of physical destruction of a pressure cylinder increases with increasing temperature load. Acetylene is a significant hazardous gas in cylinders. If the destruction pressure is reached, the cylinder is torn into two or more pieces, followed by the gas release to the environment. The presence of ignition sources could lead to the formation of the fireball phenomenon. This phenomenon generally reaches approximately ten meters in diameter and can be accompanied by a blast wave and a spread of the cylinder's fragments or surrounding objects. The consequences of this type of fire could be fatal. Shooting through the cylinder shell may lead to the mitigation, if not elimination, of the effects of the uncontrolled destruction mentioned above. As a result of the review of relevant publications, several states commonly use this method as a standard procedure. Internal gas is released through the resulting hole, the pressure drops down and the gas creates a fire jet or disperses to surroundings. This study is based on a large-scale experiment where acetylene cylinders were placed inside a prepared woodpile and exposed to fire. In the fire condition, the cylinders exploded and created fireballs, or were penetrated via shooting and created fire jets. The results from these tests were compared, focusing on the shooting procedure, then analyzed and discussed.
Air pollution associated with total suspended particulate and particulate matter in cement grinding plant in Vietnam
(MDPI, 2021) Thai, Tinh; Bernatík, Aleš; Kučera, Petr
Air pollution associated with suspended particles has become a significant concern in Vietnam recently. The study aimed to (1) investigate dust sources; (2) measure concentration levels of Total Suspended Particulate (TSP), Particulate Matter (PM) fractions; (3) identify silica levels and the correlation with respirable particles at a cement grinding plant in Vietnam. A total of 312 samples (52 TSP, 160 PMs) at 13 processes were measured using the direct-reading dust meter. The silica composition was analyzed in a certified laboratory using the X-ray fluorescence (XRF) technique. SPSS version 26 for Window was used to analyze the data. The operations of the cement grinding plant created multiple dust sources from the jetty to the cement dispatch process. The TSP levels ranged 0.06-38.24 mg m(-3), and 40.38% (n = 21) TSP samples exceeded the Permissible Exposure Limit (PEL) for an 8-h working shift. Besides that, there was a wide range and significant concentration levels of PMs in the cement processes. The levels of PMs were PM1 (0.00-0.06 mg m(-3)), PM2.5 (0.01-0.83 mg m(-3)), PM4 (0.02-4.59 mg m(-3)), PM7 (0.03-16.94 mg m(-3)), and PM10 (0.04-26.85 mg m(-3)). The highest mean levels of PMs factions were measured at the pre-grinding process. The inefficient operation of the dust collector contributed a significant factor to the dust dispersion in this process. The silica's mean (SD) composition in respirable dust was 20.4% (0.86) and was not significantly different amongst the processes. There was a significant correlation between the levels of respirable dust and silica exposure in the cement grinding plant (r = 0.99). The improvement of indoor air quality is needed to prevent health effects on cement workers.
Influence of the pyrotechnic igniter composition aging on explosion parameters of dispersed dusts
(MDPI, 2021) Szabová, Zuzana; Kuracina, Richard; Sahul, Martin; Mynarz, Miroslav; Lepík, Petr; Kosár, László
A commercially available pyrotechnic igniter was used according to the EN 14034 and ASTM E1226a Standards to study the explosiveness of dispersed dusts. Its pyrotechnic composition consists of 1.2 g of zirconium (40% wt.), barium peroxide (30% wt.) and barium nitrate (30% wt.). The energy released during the combustion of that amount of composition is 5 kJ. The article investigates the influence of aging of the pyrotechnic composition in the igniter on its initiation parameters. In the study, igniters of different years from date of manufacture were used: Igniter 1, manufactured in 2021 (less than 1 year from date of manufacture), and Igniter 2 (more than 2 years from date of manufacture). The study was performed in the KV 150M2 explosion chamber with a volume of 365 L and the 20 L sphere chamber with a volume of 20 L. A standard sample of Lycopodium clavatum was used in the KV 150M2 explosion chamber. Magnesium and benzoic acid were used as the samples in the 20 L sphere explosion chamber. The experiment showed that the explosion pressure P-max of the igniter with more than 2 years from date of manufacture decreased by up to 10%, while the value of the explosion constant K-st decreased by up to 40%. The attained results proved that aging of igniters affects their explosion parameters and measurement accuracy.
Occupational exposure to nanoparticles originating from welding – case studies from the Czech Republic
(Nofer Institute of Occupational Medicine, 2021) Berger, Filip; Bernatíková, Šárka; Kocůrková, Lucie; Přichystalová, Radka; Schreiberová, Lenka
Background: Nanomaterials are virtually ubiquitous as they are created by both natural processes and human activities. The amount of occupational exposure to unintentionally released nanoparticles can, therefore, be substantial. The aim of the study was to determine the concentrations of incidental nanoparticles that workers can be exposed to during welding operations and to assess related health risks. The specific focus on welding operations was determined based on the fact that other case studies on the manufacturing industry confirm significant exposure to incidental nanoparticles during welding. In the Czech Republic, 92% of all industrial workers are employed in the manufacturing industry, where welding operations are amply represented. Material and Methods: The particle number concentrations of particles in the size range of 20-1000 nm and particle mass concentrations of inhalable and PM1 fractions were determined via measurements carried out at 15-minute intervals for each welding operation by static sampling in close proximity to the worker. Measurements were obtained using the following instruments: NanoScan SMPS 3910, Optical Particle Sizer OPS 3330, P-TRAK 8525 and DustTrak DRX 8534. The assessed operations were manual arc welding and automatic welding. Results: The observed average particle number concentrations for electric arc welders ranged 84x10(3)-176x10(3) #/cm(3), for welding machine operators 96x10(3)-147x10(3) #/cm(3), and for a welding locksmith the obtained average concentration was 179x10(3) #/cm(3). The determined average mass concentration of PM1 particles ranged 0.45-1.4 mg/m(3). Conclusions: Based on the conducted measurements, it was confirmed that there is a significant number of incidental nanoparticles released during welding operations in the manufacturing industry as a part of production and processing of metal products. The recommended occupational exposure limits for nanoparticle number concentrations were exceeded approximately 4-8 times for all assessed welding operations. The use of local exhaust ventilation in conjunction with personal protective equipment, including FFP2 or FFP3 particle filters, for welding is, therefore, recommended.
Biochar – An efficient sorption material for the removal of pharmaceutically active compounds, DNA and RNA fragments from wastewater
(Elsevier, 2021) Bimová, Paula; Roupcová, Petra; Klouda, Karel; Matějová, Lenka; Vojs Staňová, Andrea; Grabicová, Kateřina; Grabic, Roman; Majová, Veronika; Híveš, Ján; Špalková, Viera; Gemeiner, Pavol; Celec, Peter; Konečná, Barbora; Bírošová, Lucia; Krahulcova, Monika; Mackuľak, Tomáš
Wastewaters are considered a remarkable source of micropollutants capable of influencing the environment both directly and indirectly. Here we tested porous ecological carbon (Biochar), an effective sorbent material for removing pharmaceuticals, drugs, and their metabolites found in wastewaters. The tested Biochar type was first characterised and used for adsorption experiments of selected micropollutants from a municipal WWTP (wastewater treatment plant) effluent sample. The sorption efficiency was studied on selected pharmaceuticals due to their common presence in aquatic ecosystems. The results show that the studied Biochar type removed the pharmaceuticals with high efficiency (above 90%), so this material can potentially be applied in wastewater treatment. We achieved greater than 99% efficiency in total RNA removal from wastewater. Wastewater might contain infectious RNA fragments of the SARS-CoV-2 virus. However, Biochar can be used as a sorbent in wastewater treatment to remove antibiotic resistance genes. We have also observed a total DNA removal ability of Biochar. On the other hand, the total number and antibiotic-resistant coliform bacteria and enterococci were not changed after Biochar wastewater treatment.
Noise pollution and its correlations with occupational noise-induced hearing loss in cement plants in Vietnam
(MDPI, 2021) Thai, Tinh; Kučera, Petr; Bernatík, Aleš
Noise-Induced Hearing Loss (NIHL) is a global issue that is caused by many factors. The purpose of this study was to survey noise level to identify NIHL and its relationship with other factors in cement plants in Vietnam. Noise level was measured at one cement plant and three cement grinding stations located in the South of Vietnam. The audiometric data of exposed workers were surveyed to determine NIHL. Finally, the relationship between NIHL and noise level in cement plants was determined. The results show that noise level in almost all processes exceeded the permissible exposure limit (PEL). In this study, 42 cases (10% of exposed workers) with occupational NIHL were found with mean age (SD) of 49 (9.0) years. All NIHL cases were found in the departments in which the noise level exceeded the PEL, which included quarry (n = 16), maintenance (n = 12), production (n = 10), co-waste processing (n = 3) and quality assurance (n = 1). There was a positive and significant correlation between the NIHL and the excessive noise exposure in the cement plants (r = 0.89, p = 0.04).

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