Fine Dust Particles Research Articles

MODIFICATION OF ORGANOSILICON EMULSIONS FOR OBTAINING HYDROPHOBIC SURFACES AND FOR REDUCING DUST DEPOSITION

Intense coal mining at the territory of our country, related to the growing amounts of exported fuel, promotes the development of logistic infrastructure but at the same time causes a worsening of the environmental situation near coal mining enterprises. One of the ways to cope with the surfaces that generate dust, in particular fine coal dust particles, is surface treatment with hydrophobising organosilicon emulsion. However, the problem connected with enhancing the hydrophobicity of coatings formed by the emulsion has not been solved yet. This parameter is estimated by determining the wetting angle. The efficiency of modification and the coalescing ability of various additives in the aqueous emulsions of organosilicon liquid GKZh-94 are evaluated in the present work from changes in the wetting angle. The dependences of film wettability changes on the modifying and coalescing agents, and on their amount in the emulsion are demonstrated. The dependences of wetting angle changes on the amounts of the modifying and coalescing agents in the emulsion are plotted on the basis of the polynomial approximations of functions. It is established that preliminary modification of the emulsifier causes an increase in the hardness of polyvinyl alcohol, which hinders coalescence of particles in the emulsion. It is also determined as a result of a comparative analysis that the best wetting angle values are detected for the emulsions with the emulsifier modified with a small amount of glutaric aldehyde, with the high concentration of ethylene glycol as a coalescing agent. The use of glutaric aldehyde in the amount of 0.1-0.25 % and ethylene glycol in the amount of 3-6 % of the total mass of emulsion will allow an increase in the wetting angle of the formed coatings to 125°.

Analysis of Size Distribution, Chemical Composition, and Optical Properties of Mineral Dust Particles from Dry Deposition Measurement in Tenerife: Determined by Single-Particle Characterization

In this paper, individual particle analysis by automated scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) was used to assess the size-resolved information of composition, size distribution, complex refractive index, and mixing state of mineral dust aerosol particles collected using different passive and active samplers. In the study, over 120,000 particles from 53 samples were analyzed. Results show that dust particles are the dominating mineral particle type during this campaign, comprising different classes of silicates, Si-rich (quartz-like), Ca-rich (calcite-like), CaMg-rich (dolomite-like), and CaS-rich (gypsum-like). The results also show that there is no significant difference in composition between suspended and deposited dust particles. By using the particle composition, the size-resolved complex refractive index of dust particles was calculated. The real part of the refractive index varied between 1.71 and 1.53 for wavelengths in the range of 370 to 950 nm. The imaginary part of the refractive index, determined mostly by iron oxide, varied between 3.28×10−4 and 7.11×10−5 for wavelengths ranging from 250 nm to 1640 nm. In addition, the refractive index values showed a slight decrease with increasing particle size. We also analyzed the potential for buffering of the acid mobilization of iron by other dust compounds. For particles which contain both iron (Fe) and (unprocessed) calcium (Ca), acids that are able to dissolve insoluble Fe particles can react with the Ca particles before reacting with Fe, but eventually, with longer processing time, the Fe particles could be processed. By analyzing the ratio of sulfate mass to the total aerosol mass of individual particles, the mixing state of sulfate particles to the total dust particles was investigated. The analysis showed that the finer dust particles were associated with higher content of sulfate, while the coarse dust particles correspond to lower sulfate contents, revealing that only fine mode sulfate is more internally mixed with mineral dust aerosol particles.

Development of high performance granite fine fly dust particle reinforced epoxy composites: structure, thermal, mechanical, surface and high voltage breakdown strength properties

The granite waste generated from the granite cutting and polishing industries contributes to lot of environmental contamination and health hazards. In the present work, an attempt has been made to assess the method to minimise environmental problems associated with granite dust pollution to the possible extent by converting the granite dust waste into value added high voltage electrical insulator products. Two types of epoxy matrices comprising bisphenol-A diglycidyl ether-phenalkamine (ER-1) and bisphenol-A diglycidyl ether-methyl hexahydrophthalic anhydride (ER-2) separately reinforced with varying weight percentages of (20, 40, 60, 80 and 100 wt%) of granite dust. The matrices and composites obtained were characterized for their structural, morphology, hydrophobic properties, thermal stability, mechanical strength, thermal conductivity, thermal resistivity, electrical resistivity, breakdown voltage and dielectric strength behaviour using appropriate analytical testing methods. Data resulted from different studies, it was inferred that the composites prepared using ER-2 possess better properties than those of ER-1. The composites with 100 wt% of cutting waste granite fly dust reinforced ER-2 possesses the higher values of electrical surface resistivity (5.22 × 1012 Ω), and electrical volume resistivity (5.60 × 1013 Ω) than those of neat ER-2 matrix (surface resistivity 4.82 × 109 Ω and volume resistivity 2.48 × 1013 Ω). The breakdown voltage and dielectric strength of ER-2 matrix were increased from 28 ±1 kV and 14 ± 0.5 kV/mm to 34 ±1 kV and 17 ± 0.5 kV/mm respectively, when reinforced with 100 wt % granite dust. The value of breakdown voltage was increased by 22% for 100 wt% granite dust reinforced composites when compared to that of neat epoxy matrix.

Effect of Low-Thermal Treatment on the Particle Size Distribution in Wood Dust after Milling.

The thermal treatment of wood can improve the appearance of the wood product's surface, its dimensional stability, and resistance to fungal attacks. However, the heat treatment changes the technological properties of wood, making it a new engineering material. This work investigates the effect of the low-thermal treatment of birch wood (Betula pendula Roth.), European beech wood (Fagus sylvatica L.), and alder wood (Alnus glutinosa L.) on the fine dust particles creation during woodworking. The samples of thermally treated wood with temperatures commonly used for the change of wood colour (105, 125, and 135 °C) were compared with reference samples made of natural wood. All 12 variants of the tested woods were milled using the 5-axis CNC machining center (20 mm diamond cutter, rotational speed 18,000 rev·min-1, the depth of cut 3 mm, feed rates of 2, 4 and 6 m∙min-1). A sieving analysis method allowed measuring the dust particle size distributions in all dust samples. The experiment's result analysis points out that wood type, thermal treatment, and feed rate meaningfully affect the size distribution of dust particles. Compared to birch wood and beech wood, the milling of alder wood samples created a much higher content of the finest dust particles, with particle sizes smaller than 0.032 mm. Increased temperatures in thermal treatment increase the share of fine dust particles with sizes smaller than 0.125 mm, compared to wood in its natural state. Milling with a lower feed rate (2 m·min-1) creates finer dust than processing with higher feed rates (4 and 6 m·min-1). Generally, the milling of alder in a natural or thermally treated state is a source of fine dust particles, particularly at low feed speed-rate milling, compared to birch and beech wood. In general, these results indicate that the low temperature thermal treatment parameters attribute new technological properties to all thermally modified types of wood tested.

Vertical characterization of fine and coarse dust particles during an intense Saharan dust outbreak over the Iberian Peninsula in springtime 2021

Abstract. An intense and long-lasting Saharan dust outbreak crossed the Iberian Peninsula (IP) from the southwest (SW) to the northeast (NE) from 25 March until 7 April 2021. This work aims to assess the optical and mass contribution of both fine and coarse dust particles along their transport. Five Iberian lidar stations were monitoring the transport and evolution of the Saharan dust particles, i.e. El Arenosillo/Huelva, Granada, Torrejón/Madrid and Barcelona in Spain, and Évora in Portugal. The particular meteorological conditions determined the aerosol scenario along the overall dust event, differing in the first part of the event (25–31 March), in which the strongest dust incidence occurred on 29–31 March at the south and central stations and 1 April at Barcelona, from the second one (1–7 April). The use of the two-step POLIPHON algorithm showed the relevance of using polarized lidar measurements for separating the aerosol properties of dust fine and coarse particles as an added value. Both the fine dust (Df) and coarse dust (Dc) components of the total particle backscatter coefficient (total dust, DD = Dc + Df) were separately derived. The dust plume was well-mixed with height and no significant differences were found in the vertical structure of both the Dc and Df particle backscatter coefficients. From the beginning of the dust outbreak until 1 April, the vertical Df / DD mass ratio was nearly constant in time at each station and also in altitude with values of ∼ 10 %. Moreover, the mean dust optical depth at 532 nm was decreasing along that dust pathway, reporting values from SW to NE stations of 0.34 at El Arenosillo/Huelva, 0.28 at Granada, 0.20 at Évora, 0.28 at Torrejón/Madrid, and 0.14 at Barcelona, although its Df / DD ratio remained almost constant (28 %–30 %). A similar pattern was found for the total dust mass loading and its Df / DD ratio, i.e. mostly decreasing mean mass values were reported, being constant in its Df / DD ratio (∼ 10 %) along the SW–NE dust pathway. In addition, the episode-mean centre-of-mass height increased with latitude overall, showing a high variability, being greater than 0.5 km at the southern sites (El Arenosillo/Huelva, Granada, Évora) and ∼ 1.0 km at Torrejón/Madrid and Barcelona. However, despite the relatively high intensity of the dust intrusion, the expected ageing of the dust particles was hardly observed, by taking into account the minor changes found in the contribution and properties of the coarse and fine dust particles. This is on the basis that the IP is relatively close to the Saharan dust sources and then, under certain dust transport conditions, any potential ageing processes in the dust particles remained unappreciated. The following must be highlighted: the different relative contribution of the fine dust particles to the total dust found for their optical properties (∼ 30 %) associated with the radiative effect of dust, with respect to that for the mass features (∼ 10 %) linked to air quality issues, along the overall dust event by crossing the IP.

STATISTICAL ASSESSMENT OF THE DYNAMICS OF CHANGES IN THE CONCENTRATION OF PM 10 AND PM 2.5 PARTICLES IN THE AIR OF URBANIZED AREAS

This article addresses the issue of atmospheric pollution caused by solid particles in urban environments. The presence of PM10 and PM2,5 particles in the air of major cities and industrial areas worldwide has been examined. An evaluation of atmospheric pollution levels with PM10 and PM2,5 particles in Kostopil, considering current air quality standards in Ukraine and the European Union, has been conducted. The authors employed the gravimetric method to measure the levels of suspended dust particles (PM10 and PM2,5) in Kostopil from autumn 2022 to winter 2023. The study revealed an excessive amount of fine dust particles in the city's air, exceeding the maximum permissible values outlined in regulatory laws by 2.1-2.7 times. Furthermore, the monitoring of changes in suspended dust particle levels showed peak values of PM10 = 1.15 mg/m³ in January and PM2,5 = 0.96 mg/m³ in December. The results of the statistical analysis of particle level distribution in Kostopil's urban areas indicated the statistical significance of certain distribution parameters, specifically SW-W and D for PM10 and PM2,5 particle classes.

Self-Powered Fine Dust Filtration Using Triboelectrification-Induced Electric Field

Particulate matter (PM) in the environment can adversely affect the health of living things. However, high removal efficiency and low-pressure loss are crucial design challenges for any air filtration system. To circumvent the challenge, here, we demonstrate a novel triboelectric (TE) air filtration system that is based on a rotation-type triboelectric nanogenerator (TENG) and a filter comprising two sets of plates: primary and secondary, that are placed in the airflow channel. When the TENG charges the two plate sets with opposite charges, the flowing air particles are charged at the primary plates and are collected, due to an electric field, at the secondary plates. The TE filter has demonstrated a PM2.5 removal efficiency of ~ 99.97% for the fine dust particles, and it remains stable even after several washing cycles. The pressure loss is almost two orders less than the high-efficiency particulate air filter. Since the airflow itself can drive the TENG, the TE filter can potentially be integrated with any air conditioning system for fine dust filtration in offices, automobiles, etc.

A multiphase data fusion approach based on CFD-DEM for gas–solid flow simulation in PDSS

In order to improve the operating environment of the bulk material transfer system and promote the digital construction of such systems, a new multiphase data fusion method is proposed for simulation of dust suppression in the digital twin system. It is applied to the multiphase flow motion simulation in a new Powerless Dust Suppression System (PDSS), and the results show that the method based on Discrete Element Methods (DEM) and Computational Fluid Dynamics (CFD) can well calculate the interaction between air and bulk material. A stable vortex airflow field can be generated in the structure of the PDSS, and the speed difference between the inlet and the exit of transfer chute is almost 0%, which can effectively bind the fine coal dust particles and prevent dust diffusion. In the structure where the curtain is arranged, a part of the vortex airflow will flow back after the action of the curtain, the backflow air can further reduce the speed of the airflow, and the dust-laden airflow has more time to contact the curtain and the material to cause sedimentation, which can further prevent dust emission. This study provides a practical reference for the design of transfer dispatching station and other similar particle–fluid digital twin systems.

Air Quality and Health Status of the Population in a District of Bulgaria

The problems related to the environmental pollution caused by anthropogenic activity are particularly significant worldwide. The aim of the study is the quality of the atmospheric air in the region of Stara Zagora, Kazanluk Municipality and Galabovo Municipality and the morbidity of the population. The data are provided by RHI (Regional Health Inspectorate), RHIF (Regional Health Insurance Fund) and MI (Medical Institutions) Stara Zagora for a two-year period 2017-2018. Documentary, statistical and sociological methods are applied. For the period 2017-2018, in Stara Zagora, Ruzhena and Galabovo are reported excessive concentrations of PM10 (fine dust particles). There is an increase in the number of respiratory diseases with the highest relative share of acute bronchitis and pneumonia, especially in children. In order to reduce atmospheric air pollution and the health consequences for the population, it is necessary to carry out architectural and technological measures in the harmful productions of enterprises by installing modern purification facilities. Infrastructural measures such as improving the road surface and using ring roads are also needed.

A reusable nanofibrous air filter with anti-wetting microbead coating

Filtration technologies for fine dust particles have garnered attention as public awareness of air pollution has increased. In this study, we report a microbead-coated polyacrylonitrile nanofibrous membranes (MB-NFMs) filter, which is a reusable PAN nanofiber-based air filter with high dust-filtration efficiency. The MB-NFMs filter comprises a dual-layer structure composed of hydrophilic PAN nanofibers coated with hydrophobic microbeads to produce high filtration efficiency and water droplet cleaning ability. This membrane has water contact angles of approximately 144°, which allows water droplets to roll off its surface and carry captured dust particles with them. Furthermore, we discovered that the MB-NFMs filter has sufficient wetting resistance to maintain its hydrophobicity under raindrop impacts. The MB-NFMs filter had a removal efficiency of over 99.8% for PM2.5. Repetitive dust-filtration and water droplet-cleaning cycles were performed to evaluate the MB-NFMs filter's ability to clean water droplets. The filtration efficiency was higher than 99.8% throughout the tests, and the pressure drop was recovered by 99% after each cleaning cycle. The fabricated MB-NFMs filter is a viable solution for highly efficient and reusable dust-particle filtration. The MB-NFMs filter does not require periodic maintenance due to its water droplet cleaning ability, providing an economic advantage over conventional air filters.

Study on air curtain cooperative spray dust removal in heading face based on swirl theory

With the improvement of mechanization, fully mechanized excavators are widely used in roadway excavation, which produces a large number of fine dust particles in the process of tunneling. The smaller the dust particle size, the greater the impact of the environment, and the more difficult it is to be captured. Experiments and numerical simulations have been used to study the cooperative spray dust removal of the wall-mounted air duct based on the swirl theory, which is to prevent the escape of dust particles in the long-pressure and short extraction ventilation. Under the condition that the power of the push-in and extraction fans remain unchanged, it is determined that when the aspect ratio of air outlet is 6:1, the airflow can form an annular vortex area on the left side of the roadway, and the airflow velocity in 30 % of the area is greater than 1 m/s. When the opening angle is between 120° and 150°, the wall effect of airflow movement is weak, and the airflow velocity of 70 % of the cross-sectional area of the roadway is larger than 2 m/s, which enables the air curtain to block about 70 % of the dust. Under the action of the swirl air curtain, when the spray pressure is 6 MPa, 80 % of the droplets have a particle size of less than 2.5e-5 m, and the spray effect is better. The droplets move to the tunnel section under the swirling flow, and actively control the dust, establishing an air curtain-droplet flow field, thereby blocking and capturing the excavation dust.

Effects of secondary soil aggregates on threshold friction velocity and wind erosion

AbstractSecondary aggregates (clods) attenuate wind erosion and land degradation by increasing surface roughness and reducing wind friction velocities at the soil surface. However, aggregates with low stability are erodible and may increase dust emissions by particle abrasion under saltation bombardment relative to non‐erodible aggregates. It is still not clear exactly how different secondary aggregate properties reduce, and in the presence of saltators potentially increase, wind erosion and dust emission. The objective of this study was to quantify the effects of erodible soil aggregates on the threshold friction velocities (u*t), aerodynamic roughness length (zo), and soil loss of loessial soils in the inland Pacific Northwest (iPNW) of the United States. The impact of erodible secondary aggregates in attenuating wind erosion was evaluated in terms of secondary aggregate lateral cover and density. Secondary aggregates were tested in a wind tunnel using five levels of aggregate densities. Secondary aggregates appeared to restrain wind erosion as z0 and u*t increased with increasing aggregate cover, but may significantly change wind erosion patterns by releasing more fine dust particles by abrasion. We found that, while abrasion losses contributed up to 69.3% of total soil loss for a sandy loam, total soil loss still decreased for all soils. Aggregates with greater stability may reduce soil loss with increasing secondary aggregate densities, and the rate of reduction in soil loss was up to two times higher than that for soil aggregates with lower stability.

Expected Brightness of Ejecta Caused by the DART Impact

We estimate the volume of material that could be excavated from asteroid Dimorphos and expelled into the surrounding space by the DART impact on 2022 September 26. What emerges from our computations is that the total volume of ejected material could be as high as 5710 m3. Assuming that the fraction of fine-dust particles constitutes 5% of this volume, we estimate the apparent brightness of the ejecta to be (6.5 ± 1.5) mag in the V filter. This makes ground-based astronomical observations of the DART impact on asteroid Dimorphos with small telescopes feasible.

Use of a 3D inkjet-printed model to access dust particle toxicology in the human alveolar barrier.

Fine dust particles in the air travel into our body via the airway tract and cause severe respiratory diseases. Thus, the analysis of the effects of dust particles on the respiratory system has been receiving significant research interest. However, most studies on the toxicity of dust particles involve two-dimensional (2D) cell cultures, animal models, and epidemiology. Here, we inkjet-printed athree-dimensional (3D) alveolar barrier model to study how dust particles cause respiratory diseases. The three-layered in vitro model was exposed to A2 fine test dust with varying concentrations and exposure durations. The results highlighted the destruction of the tissue architecture along with apoptosis in the bioprinted alveolar barrier. The damage at the cellular level induced an increase in the amount of pro-inflammatory cytokines secreted, followed by triggering of the signal transduction pathway and activation of transcription factors. As a consequence of the release of cytokines, the extracellular matrix was degraded, which led to the collapse of the cell structure, loss of cell polarity, and a decrease in barrier tightness. Further, the pulmonary surfactant protein-related genes in the dust-treated alveolar tissue were investigated to evaluate the possible role of dust particles in pulmonary surfactant dysfunction. This study demonstrated the use of 3D-printed tissue model to evaluate the physiological impact of fine dust particles on cytotoxicity, alveolar barrier rigidity, and surfactant secretion of an alveolar barrier.

Resistance of a sealed joint subjected to tensile stress at different temperatures

In this paper, research on the topic of Resistance of a sealed joint subjected to tensile stress at different temperatures is presented. Tensile stress is one of the physical effects acting on conventional structures. This research specifically deals with the sealing of problematic material. Aquapanel cement board is chosen as the problematic material. This board has a large amount of fine dust particles on its surface, which prevent the sealant from adhering properly to the base material. Next, two sealants and the appropriate primers are selected. The sealants used were selected based on the manufacturer's recommendations on suitability for use in sealing cementitious materials. From these three components, the Aquapanel cement board, the sealant and the primer, test specimens are made, which are tested according to the valid European standard. The results of this test are carefully recorded and further analysed. Based on the results of this test, it is possible to recommend both tested sealants for sealing cement materials that are exposed to tensile stress at different temperatures.

Pollution characteristics and risk assessment of potentially toxic elements of fine street dust during COVID-19 lockdown in Bangladesh.

Due to the COVID-19 pandemic, Bangladesh government took the measure like partial lockdown (PL) and complete lockdown (CL) to curb the spread. These measures gave a chance for environmental restoration. In this study, street dust samples were collected during PL and CL from four main urban land use categories in Dhaka city, such as industrial area (IA), commercial area (CA), public facilities area (PFA), and residential area (RA). Ten potentially toxic elements (Cr, Mn, Zn, Fe, Pb, Cu, Co, Ni, As, and Cd) in fine street dust particles (diameter < 20 μm) were determined following aqua-regia digestion and measured by inductively coupled plasma mass spectrometry (ICP-MS) to evaluate distribution, pollution sources, and potential risks to ecological systems and human health. Results showed that during PL, the concentrations of toxic elements in the dust were higher than that of CL. Cd and Fe were lowest and highest in concentration with 1.56 to 41,970 µg/g and 0.82 to 39,330 µg/g in partial and complete lockdown period respectively. All toxic elements were detected at high levels above background values where Fe with the highest and Cd with lowest concentrations, respectively. By land use, the levels of toxic elements pollution followed IA > PFA > RA > CA. Correlation analysis (CA), principal component analysis (PCA), and hierarchal cluster analysis (HCA) revealed that the sources of these analyzed toxic elements were mainly from anthropogenic which are related to industrial and vehicular or traffic emissions. Enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (CF), and pollution load index (PLI) also suggested that the dust was more polluted during PL. Exposure of toxic elements to human was mainly via skin contact followed by ingestion and inhalation. Hazard quotient (HQ) values were < 1 except for Mn through dermal contact at all sites during partial and complete lockdown, similar to hazard index (HI), while Cr further showed high non-carcinogenic risks to children. Generally, children HI values were about 5–6 times higher than those of adults, suggesting a greater vulnerability of children to the health concerns caused by toxic elements in street dust. Carcinogenic risk (CR) values via ingestion pathway indicated all elements (except Pb) had significant health effect, while CR value by inhalation results showed no significant health effect. Cumulative carcinogenic risk (CCR) value had significant health effect except Pb in all land use categories. CCR values decreased during CL and reached at acceptable limit for most of the cases. This research provides a message to the local governments and environmental authorities to have a complete assessment of toxic elements in the street dust of Dhaka megacity in order to assuring public health safety and ecological sustainability.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-022-22541-8.

Novel post-treatment of removed fine dust particle: Electrorheological application

Capturing and removal (or post-treatment) of fine dust particles is crucial to solving environmental issues, while various studies have been conducted on capturing particulate matter (PM), which consists of fine dust particles. Post-treatment, or the usage of removed fine dust particles, however, has not been deeply investigated. In this study, an electrorheological (ER) fluid system with 5 vol% of fine dust particles dispersed in silicone oil is introduced as an alternative to apply fine dust particles as they are a mixture of various chemical compounds, including organic pollutants. Fine dust particles are found to be suitable for use in ER fluids owing to their particle polarity. Both rheological characteristics such as flow curve, ER efficiency, dynamic moduli, and relaxation modulus and polarization analyses of the fine dust particle-based ER fluid are conducted using dielectric measurement, clearly showing that the captured fine dust particles can be newly adopted as a smart ER material. Yield stresses obtained give the slope of 2.0 with applied electric field strengths, demonstrating that the ER fluid follows the polarization mechanism. Economic issue of the fine dust particles as for the ER material along with its lifetime and potential applications is also qualitatively considered.

An Efficient Automatic Water Sprinkler Design for Operate in Dust Environment

The dust density within the environment must be continuously monitored in open cast mines. Water sprinklers are used to suppress the dust in mining field. Water sprinklers capacity used are of 28,000 and 70,000 L. These conventional water sprinklers comprise of 4 kinds of sprinkling thus the operator must choose and actuate any 1 type of sprinkling which is appropriate to suppress the dust. The traditional water sprinkler is worked physically by the operator that is operator turns on the type of sprinkling dependent on the dust seen by him. This technique does not completely suppress the dust and it’s not accurate. Furthermore, water is squandered if the dust density is according to the directions given by central pollution control board. Supportive to the above background, it is necessarily essential to actualize the water sprinkling system automatically which measures the dust density contained in mine atmosphere and likewise module will consequently actuate the sprinkling so as to suppress the dust in the environment. This technology is compatible to inbuild display for continuous monitoring of dust concentration also the system has both auto/manual operation. At the point when the dust concentration crosses the admissible value automatically system will activate solenoid driver to start out the sprinkling activity. Therefore, the designed dust monitor module is employed to implement an automatic system, utilizing advanced technology to monitor the density of fine dust particles in the mining environment &amp; accordingly the sprinkling operation is actuated with minimal human intervention.

Dust Removal Mechanism of the Vibrating String Filter with Charged Water Mist

The traditional dust removal technology is difficult to meet the strict requirements of environmental protection, so it is of practical significance and research value to study how to purify fine dust in workshop. Fine dust can be suspended in the atmosphere, while reducing the air quality. Excessive inhalation of dust may result in disease. So it should be paid close attention to dust control. The water mist charging process has experienced three stages: induction charge, corona charge transition, and corona charge. When the discharge distance is 80 mm, the charge-mass ratio of droplet and the current of water mist are most affected by corona voltage. The significant impact analysis of orthogonal experiment is studied. The result of the orthogonal experiment is analyzed by the variance method. It is noted that the inlet wind speed has the highest influence, and the discharge distance has a least influence on the dust removal efficiency. The discharge distance is 80 mm, and the voltage working band is suitable for the normal voltage regulation of the electrostatic precipitator. The condensation efficiency of charged droplets on dust is beneficial to reduce the negative effect of excessive wind speed on wet vibrating string grid and to improve the effective handling volume of dust collector. The charge-mass ratio of water mist is improved effectively, and the dust removal efficiency is increased in the vibrating string filter with charged water mist. Theoretical analysis and experimental studies showed that the vibrating string filter with charged water mist is as a new composite efficient dust removal technology that can effectively deal with the purification of fine dust particles in the gas stream, especially in respiratory dust removal.

Microplastic: A particulate matter(PM) generated by deterioration of building materials

Particulate matter (PM), an inhalable material, is generated from various sources, including building materials. To maintain indoor air quality, it is necessary to analyze harmful substances and establish a method for their remediation. The purpose of this study is to identify the particles generated during the deterioration of building materials and analyze the composition of fine dust particles with respect to the degree of deterioration. The concentration of particles generated was analyzed using an SPS30 PM sensor in the built chamber. PM10 and PM2.5 levels of the maximum of 41.95 mg/m3 and 20.63 mg/m3, respectively, were generated from the tested building materials. The components of the collected PM were carbon, hydrogen, and silicon, among others, which are high-molecular-weight compounds. Particles of size 2.5 µm or less were detected, and the possibility of generating nanoplastics was investigated.