Fiber Filters Research Articles

Evaluating environmental DNA detection of a rare fish in turbid water using field and experimental approaches.

Detection sensitivity of aquatic species using environmental DNA (eDNA) generally decreases in turbid water but is poorly characterized. In this study, eDNA detection targeted delta smelt (Hypomesus transpacificus), a critically endangered estuarine fish associated with turbid water. eDNA sampling in the field was first paired with a trawl survey. Species-specific detection using a Taqman qPCR assay showed concordance between the methods, but a weak eDNA signal. Informed by the results of field sampling, an experiment was designed to assess how turbidity and filtration methods influence detection of a rare target. Water from non-turbid (5 NTU) and turbid (50 NTU) estuarine sites was spiked with small volumes (0.5 and 1 mL) of water from a delta smelt tank to generate low eDNA concentrations. Samples were filtered using four filter types: cartridge filters (pore size 0.45 μm) and 47 mm filters (glass fiber, pore size 1.6 μm and polycarbonate, pore sizes 5 and 10 μm). Prefiltration was also tested as an addition to the filtration protocol for turbid water samples. eDNA copy numbers were analyzed using a censored data method for qPCR data. The assay limits and lack of PCR inhibition indicated an optimized assay. Glass fiber filters yielded the highest detection rates and eDNA copies in non-turbid and turbid water. Prefiltration improved detection in turbid water only when used with cartridge and polycarbonate filters. Statistical analysis identified turbidity as a significant effect on detection probability and eDNA copies detected; filter type and an interaction between filter type and prefilter were significant effects on eDNA copies detected, suggesting that particulate-filter interactions can affect detection sensitivity. Pilot experiments and transparent criteria for positive detection could improve eDNA surveys of rare species in turbid environments.

An overview of sustainable greywater treatment processes

Greywater refers to all domestic wastewater generated, with the exception of sewage. Greywater exhibits a varied composition that mirrors the lifestyle of the residents and the chemicals they utilize within their households. The environment is favourable for the proliferation of bacteria, indicating that it has to be treated before being reused. The treatment objectives also include the removal of organic pollutants, heavy metals, diseases, and other microorganisms. The predominant approach for treating greywater is to pass it via biofilm systems. Using mulch beds in close proximity to crops or trees is a viable alternative to irrigating the entire region. The basic methods of grey water treatment are filtration, coagulation, reverse osmosis, and adsorption, and the energy and resource requirements of the treatment systems differ. They often rise as the level of treatment rises, leading to a bias for natural systems such as sand or fiber filters and built wetlands. These natural systems are more suitable for small-scale greywater treatment since they are more sustainable, eco-friendly, and low-cost.This review finds different approaches to redefine the perception of sustainable greywater management in order to provide assistance to both humans and agriculture.

Study of the water cleaning process by using CFD-DEM method: A case study of coarse filter material

In this paper, the CFD-DEM coupling method was utilized to study the water cleaning and regeneration process of fibrous filter material. The effects of cleaning flow rate, time and adhesion force on the particle removal process were simulated. The results showed that the particle removal rate had a diminishing marginal effect with the increasing of cleaning flow rate. More than 80% of the particles were removed in the initial period, and then tended to stabilize. The higher the flow rate, the shorter the time needed to achieve stability. For G4 filter material, the function between the particle removal rate and the cleaning flow rate and time was given, and the best cleaning flow rate was 1.2 m/s while the cleaning time was 30 seconds. The surface energy of the fibers plays a dominant role in the cleaning process, and the reduction 1/4 of the surface energy of the particles can effectively improve the cleaning and regeneration performance.

Preparation of porous polylactic acid nanofibers and application in non-electret high-efficiency filtration composites.

Air pollution caused by fine particulate matter (PM0.3) has drawn increasing attention as an overwhelming threat to public health. Electret treatment is commonly used to improve the filtration performance of commercial fibrous filter materials by enhancing the electrostatic adsorption effect, but it is greatly affected by environmental factors (especially humidity). Moreover, filter materials are generally non-degradable and non-recyclable, causing serious environmental pollution. Herein, a strategy to manufacture fully degradable polylactic acid (PLA) filtration composites based on porous PLA nanofibers prepared by electrospinning was investigated in this study. Porous, bead-on-string and conventional PLA nanofibers could be obtained by adjusting spinning condition parameters. The porous PLA nanofibers exhibited 9.8 times greater specific surface area (24.01 m2 g-1) and 18 times more cumulative pore volume (0.108 cm3 g-1) than conventional PLA nanofibers. More importantly, fibrous filtration composites based on porous PLA nanofibers possessed a high PM0.3 filtration efficiency (99.9989%), low pressure drop (90.35 Pa) and high air permeability (72.4 Pa-1) at an air flow rate of 32 L min-1 without electret treatment. The fibrous filtration composites based on conventional or bead-on-string PLA nanofibers also exhibited excellent filtration performance (>99.99%), but the associated high pressure drop and low air permeability limited their application.

An eco-friendly solution for greywater treatment via date palm fiber filter

Greywater reuse emerges as a promising solution, being a renewable resource with relatively low treatment costs due to its low pollutant content. In Saudi Arabia, ablution water (AW) serves as a significant example of greywater due to its substantial quantities. This study introduces an assessment of a pilot scale sustainable filtration system for treating AW for reuse purposes and its water savings potential in mosques. Various AW samples were collected from 24 mosques distributed across Riyadh, Saudi Arabia, considering geographic location and local activity. The collected samples underwent measurement and comparison of total dissolved solids (TDS), pH, conductivity and turbidity. A filtration process was conducted using date palm fibers (DPFs) as a green filtration media with varying thicknesses to achieve optimal TDS and turbidity removal. The findings exhibited significant decreases in turbidity, up to 90%, while TDS and conductivity lowered by up to 15%. pH levels varied based on the surrounding area's activities, decreasing for domestic and increasing for commercial and industrial regions, meeting the standard pH environmental levels. This study sheds light on the potential of greywater recycling, contributing to efforts in mitigating water scarcity and promoting sustainable water management practices.

Surface plasma modification of cellulose acetate fiber filter for the adsorption of typical components in smoke components.

Surface modification of cellulose acetate filter rods with low temperature plasma was performed to explore the retention and adsorption effect of modified filter rods on typical components (CO, H2O, benzene, and formaldehyde) in cigarette smoke. The surface structure and composition of the cellulose acetate filter rods were modified by changing the plasma treatment time. The modified filter rods were characterized by N2 physical adsorption (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), contact angle of H2O, Fourier transform infrared spectroscopy (FTIR) and in situ DRIFTS. Various functional groups were found on the surface of filter rods with the introduction of plasma modification, which exhibited strong retention performance for water vapor in cigarette smoke at room temperature and significantly enhanced adsorption for harmful substances (CO, benzene, and formaldehyde) in cigarette smoke.

Indoor air concentrations of PM2.5 quartz fiber filter-collected ionic PFAS and emissions to outdoor air: findings from the IPA campaign.

Per- and polyfluoroalkyl substances (PFAS) are prevalent in consumer products used indoors. However, few measurements of ionic PFAS exist for indoor air. We analyzed samples collected on PM2.5 quartz fiber filters (QFFs) in 11 North Carolina homes 1-3 times in living rooms (two QFFs in series), and immediately outside each home (single QFF), for 26 ionic PFAS as part of the 9 months Indoor PFAS Assessment (IPA) Campaign. All targeted PFAS, except for PFDS and 8:2 monoPAP, were detected indoors. PFBA, PFHpA, PFHxA, PFOA, PFOS, and 6:2 diPAP were detected in >50% of indoor samples. PFHxA, PFOA, and PFOS had the highest detection frequency (DF = 80%; medians = 0.5-0.7 pg m-3), while median PFBA concentrations (3.6 pg m-3; DF = 67%) were highest indoors. Residential indoor air concentrations (sum of measured PFAS) were, on average, 3.4 times higher than residential outdoor air concentrations, and an order of magnitude higher than regional background concentrations. Indoor-to-outdoor emission rate estimates suggest that emissions from single unit homes could be a meaningful contributor to PFBA, PFOA, and PFOS emissions in populated areas far from major point sources. Backup QFFs were observed to adsorb some targeted PFAS from the gas-phase, making reported values upper-bounds for particle-phase and lower-bounds for total air (gas plus particle) concentrations. We found that higher concentrations of carbonaceous aerosol were associated with a shift in partitioning of short chain PFCAs and long chain PFSAs toward the particle phase.

Selective ion transport in large-area graphene oxide membrane filters driven by the ionic radius and electrostatic interactions.

Filters made of graphene oxide (GO) are promising for purification of water and selective sieving of specific ions; while some results indicate the ionic radius as the discriminating factor in the sieving efficiency, the exact mechanism of sieving is still under debate. Furthermore, most of the reported GO filters are planar coatings with a simple geometry and an area much smaller than commercial water filters. Here, we show selective transport of different ions across GO coatings deposited on standard hollow fiber filters with an area >10 times larger than typical filters reported. Thanks to the fabrication procedure, we obtained a uniform coating on such complex geometry with no cracks or holes. Monovalent ions like Na+ and K+ can be transported through these filters by applying a low electric voltage, while divalent ions are blocked. By combining transport and adsorption measurements with molecular dynamics simulations and spectroscopic characterization, we unravel the ion sieving mechanism and demonstrate that it is mainly due to the interactions of the ions with the carboxylate groups present on the GO surface at neutral pH.

GPF Filtration Characteristics Considering Fractal Characteristics of Particles and Filters

Abstract To reduce the emission of fine particulate matter (PM) from gasoline engines, a gasoline particulate filter (GPF) filtration model that considers the fractal characteristics of both particulate matter and filters is designed and its filtration characteristics are analyzed based on several GPF filtration models. Based on the GPF filtration mechanism, a new mathematical model of fiber efficiency filtration is established after correcting the classical filtration formula based on correcting the particle size of particles and considering the relationship between the porosity of the fiber filter and the fractal dimension of the filter. Simulation of the filtration efficiency of the established mathematical filtration model is carried out to obtain visual filtration efficiency curves. The filtration efficiency and pressure drop of the model are analyzed, and the effects of parameters such as particle fractal dimension, filter fractal dimension, filter thickness, flow rate, and fiber diameter on filtration efficiency are also comprehensively analyzed. The results show that when the fractal dimension of particles is in the range of 1.8-2.8, the most penetrating particle size decreases with the increase of the fractal dimension of particles. When the particle size is small, the effect of fractal dimension on filtration efficiency is not obvious. When the particle size is larger than the most penetrating particle range, the larger the fractal dimension, the filtration efficiency increases obviously. Considering the relationship between the fractal dimension of the filter body and the porosity and the influence of each on the filtration efficiency, the optimal fractal dimension of the filter body should be between 1.82 and 1.925, and the thickness of the filter has some influence on the filtration efficiency. The slower the gas flow rate is, the better the trapping effect will be. However, considering the problem of automobile emission, a lower exhaust speed can be chosen. Increasing the fiber diameter can improve the trapping efficiency of the model, but will reduce the porosity of the trapping collective. Therefore, the fiber diameter should not be too large under the combined action.

수처리용 섬유여과기 성능평가인자 도출 및 평가방법개발에 관한 연구

This study investigated the performance evaluation factors for the fiber filtration process in water treatment and researched the performance evaluation items and methods for assessing these factors. South Korea's water supply and sewage policies focus on modernizing civil structures and networks and introducing advanced treatment facilities. Reflecting these policies, the Waterworks Act describes the minimum requirements that water supply facilities must meet to ensure a consistent quality (water quality) of drinking water. Therefore, the Waterworks Act has introduced usage standards for water treatment processes and materials for water supply to manage the quality of drinking water. Firstly, the Ministry of Environment has issued water supply facility standards, which explain the minimum standards for water supply facilities. Secondly, there are hygiene and safety standards (suitability certification) and group standard certification. Standards and certifications are established to evaluate materials and products suitable for water supply facilities. Thus, two criteria are required to apply them to water supply facilities.
 In Republic of Korea, a new concept of water treatment process has been developed that can replace traditional water treatment processes. This involves a fiber filtration process that contracts and relaxes fiber strands, removing turbidity and suspended solids. There is a movement to adopt this process. Such fiber filters can provide better treatment efficiency, use smaller sites, and have faster processing speeds. However, the use of different evaluation methods by manufacturers has prevented consumers from accurately understanding the performance and raised doubts about the reliability of the technology.
 The result of this study is the development of a standardized performance evaluation method, and the derivation of performance evaluation factors for fiber filters. Through standardized performance evaluation factors and methods, an objective performance evaluation of the fiber filtration process can be conducted.

Flow resistance and particle separation efficiency of a rectangular-spoke rotating disk: Influence of spoke configuration and number

How to effectively separate oily particles before they enter exhaust ducts and thus reduce their accumulation has always been a challenge. This paper proposed a general rotating disk with three different spoke configurations, namely, straight spoke (SS), backward-curved spoke (BCS), forward-curved spoke (FCS), and compared their airflow characteristics and capture performance in a specified exhaust duct. Affected by the divergence effect, the BCS disk has the highest flow resistance (ΔP) and lowest separation efficiency, while the FCS disk has the lowest ΔP and highest efficiency due to the convergence effect. Subsequently, two refining methods were applied to the disks with the three spoke configurations to improve the particle separation efficiency. The FCS disk consistently maintains the highest separation efficiency (ηp), e.g., 0.83 and 0.70 for 5 μm particles at 3000 rpm under equal refining and gradient refining methods, respectively. When being refined equally, the quality factor (QF) of the FCS disk increases with the rotating speed, reaching 0.038 Pa−1 at 3000 rpm, almost equivalent to the initial QF of the fiber filter and spacer fabric, significantly higher than that of the SS disk (0.026 Pa−1) and the BCS disk (0.024 Pa−1). When gradient refining is used, however, the maximum QFs of SS, BCS, and FCS disks appear at 2200, 1800, and 2600 rpm, respectively, thus making the gradient refining method economical only at a lower rotating speed. Finally, on the base of the area under curve index and the straight linear cluster method, the applicability of disks with different spoke configurations in a residential kitchen, which is a typical scenario for collecting oily particles in civilian buildings, was evaluated. Gradient-refined SS disk, equal-refined FCS disk, and equal-refined SS disk can meet the requirements of maximum exhaust attenuation. The gradient-refined SS disk and equal-refined FCS disk have the highest quality, with ηp reaching 0.61 and 0.48, respectively. The findings can provide solid support for the design of rotating disks to separate oily particles, especially in residential kitchens.

Feasibility of Strengthening Sandy Soils Using Industry Waste as Geo-Fiber

Abstract Re-using waste generated from daily domestic usage to improve weak soils such as dune sand gives a profitable solution to both environment and the construction sector. In this paper, weak sandy soil was modified with two types of fibers derived from daily domestic use. Plastic bottle waste fiber and tainted polypropylene sediment filter fiber were embedded in the sandy soil with a rate of (0.5%,1%,1.5%, and 2%) by weight of dry soil. Toward this, the direct shear test was conducted to confirm the optimum fiber content and evaluate other parameters such as shear strength, normalized ultimate shear strength, angle of internal friction, and adhesion. The results showed that the 1.5% fiber content showed higher values of angle of internal friction and the normalized ultimate shear strength for both types of fibers. The reinforcement with plastic bottle waste fiber and tainted polypropylene sediment filter fiber enhanced the shear strength parameters and normalized ultimate shear strength. Significant improvement was noticed in the adhesion value with the addition of 2% of tainted polypropylene sediment filter fiber. finally, the effect of fiber addition on the Mohr-coulomb failure envelope was discussed.

Cigarette filter fibres as a source and sink of trace metals in coastal waters

Cellulose acetate fibres from cigarette filters represent a form of microplastic that has received little attention in the environment. In this study, a ground composite of spent, smoked filter material (FM) has been used to investigate the role of cellulose acetate fibres as a source and a sink of trace metals (Cd, Co, Cu, Ni, Pb and Zn) in coastal waters. FM suspended in river water and seawater and mixtures thereof representative of an estuarine gradient resulted in the leaching of pre-existent metals derived from the combustion of tobacco, with mean percentages of release ranging from about 40 for Pb to nearly 90 for Cd, Co and Zn. Addition of 40 μg L−1 of each metal to FM suspensions incubated for 48 h yielded mean partition coefficients (KDs) ranging from <10 L kg−1 for Co to > 100 L kg−1 for Cu, Pb and Zn, with Cu and Ni displaying a net increase in KD with increasing salinity. Adsorption is interpreted in terms of hydrophobic interactions between metal-organic complexes and the cellulose acetate surface, and in support of this assertion KDs exhibited a significant, positive relationship with published metal-humic acid binding constants. The findings of this study improve our understanding of the role of cellulosic microfibres more generally in transporting trace metals in aquatic systems.

Interaction of water mists with bibulous filter media and hygroscopic particles in pressure drop jump of fibrous filter media

This study aims to quantitatively evaluate the impact of humid airflows (unsaturated and saturated airflows with water mists), water absorption by filters (wood cellulose and polyester fibre filter media) and hygroscopic loading dust (KCl and Al2O3 particles) on the pressure drop jump. Additionally, proposed methods to alleviate this tendency are known as the “wet blockage” of filters in practice. The experimental results demonstrated that the water content of the airflows mainly contributed to the pressure drop jump in the filters. Increasing the water content from 4.2 g/m3 to 11.3 g/m3 resulted in a fourfold decrease in the water-loading capacity of the tested filter medium. However, increasing the water absorption of the filters by a factor of three times caused a reduction in the water-loading capacity of approximately 42 mg/cm2 based on the self-defined parameter tc. Furthermore, the non-hygroscopic particles delayed the pressure drop jump, which is associated with the dust-holding capacity of filters.

Identification and physico-chemical characterization of microplastics in marine aerosols over the northeast Arabian Sea

Microplastics (MPs) in the atmosphere can undergo long-range transport from emission regions to pristine terrestrial and oceanic ecosystems. Due to their inherent toxic and hazardous characteristics, MPs pose serious risks to both human well-being and the equilibrium of ecosystem. The present study outlines the comprehensive characterization, spanning physical and chemical attributes of MPs associated with atmospheric aerosols. Total suspended particulates (TSPs) were collected on a quartz fibre filter by operating a high-volume sampler for 24 h during distinct years (March, 2016 and November, 2020) at a coastal location in the northeast Arabian Sea. Subsequent to the sampling, a series of techniques were applied including density separation. The assessment and scrutiny of the MPs was carried out using stereo-zoom microscopy with supplementary validation using advanced fluorescence microscopy for enhanced precision in identification. Our comparative assessment suggests peroxide treatment followed by density separation could be a robust procedure for the definitive identification and characterization of MPs in the atmosphere. Average total abundance of MPs was found to be 1.30 ± 0.14 n/m3 in 2016 and 1.46 ± 0.12 n/m3 in 2020 with fibres, fragments and films having similar relative contributions (41 %, 31 %, 28 % in 2016 and 40 %, 35 %, 25 % in 2020). Fibres were found to be dominant morphotype followed by fragments and films over the coastal region of the Arabian Sea. In order to unravel the detailed chemical nature of these MPs, spectral analysis using μ-FTIR was carried out. The outcome of the analysis showed prevailing polymers as polyvinyl chloride and polymethyl methacrylate (50545 %) as dominant polymers followed by polyester (15 %), styrene butyl methacrylate (11 %), and polyacetal (9 %). MPs present in the vicinity of the Arabian Sea have potential to supply nutrients and toxicants, consequently can contribute to the modulation of the surface water biogeochemical processes.

Quantifying metallic components in aerosol filter samples using micro-synchrotron radiation X-ray fluorescence: With quartz filter as an example

Metals in atmospheric fine particulate matter (PM2.5) are presumed to have toxic effects. For environmental epidemiological studies, measuring the metallic components of PM2.5 collected by personal samplers and quartz fiber filters (QFF) has two key advantages: reducing exposure misclassification and enabling analyses of multiple (organic and inorganic) components on a single filter. We developed a sensitive, low-sample-consumption method to quantify the metallic components of PM2.5 collected on QFFs using micro-synchrotron radiation X-ray fluorescence (μ-SRXRF). Teflon filter is used here as a reference to test the substrate applicability of QFF. This method requires only a 5-mm-diameter portion of a QFF and can simultaneously quantify 15 metals with atomic numbers Z = 19–34 (i.e., K–Se, excluding Sc). The analysis time for each sample was 120–360 s, and the method detection limits were 0.04–36.6 ng/m3. We validated this method by performing cross-comparisons with two external methods: offline inductively coupled plasma mass spectrometry (ICP-MS) and online X-ray fluorescence (XRF). The slopes of the linear fits between the μ-SRXRF and offline ICP-MS methods varied from 0.40 to 1, with R2 values ranging from 0.62 to 0.98. The slopes of the linear fits between the μ-SRXRF and online XRF methods were between 0.29 and 0.89, with R2 values ranging from 0.39 to 0.80. We applied the proposed method to analyze 391 personal PM2.5 samples collected in an epidemiological study conducted in urban Beijing. By comparing the results with the ambient concentrations from a fixed monitoring site, we found that the concentrations of some metallic components in personal PM2.5 samples were significantly different from those in the corresponding fixed-site samples, with up to an order of magnitude difference. Because personal sampling can reduce the potential for exposure misclassifications, the high-resolution temporal analysis of metallic components in personal samples using the μ-SRXRF method could be a useful approach for exploring the health risks and identifying the sources of metallic components of PM2.5.

Generation of cylindrical vector beam pulses by using multi-wavelength EDFL with two-mode fiber filter

A multi-wavelength erbium-doped fiber laser (MW-EDFL) operating in the L-band with cylindrical vector beam outputs is proposed and experimentally investigated. The multi-wavelength lasing is realized by exploiting a two-mode fiber filter (TMFF) as the comb filter and a single-mode fiber spool with 2-km in length to suppress the mode competition. The multi-wavelength combs with channel spacing of 0.36 nm, 0.58 nm, and 1.12 nm are achieved by regulating the interference length of the TMFF, and up to 18 lasing channels are obtained with a wavelength spacing of 0.36 nm. Good long-term stability is manifested within a 100-minute duration, as the maximum peak power fluctuation of 1.96 dB and the maximum wavelength shift of 0.03 nm are measured. By adjusting the polarization controller associated with the two-mode long-period grating as a high-efficiency mode converter, radially and azimuthally polarized cylindrical vector beams of high purity are thus generated.

Amorphous nanosphere self-supporting electrode based on filter paper for efficient water splitting

Given its superior structure, the abundance of surface functional groups, and low cost, cotton fiber filtration paper can be used as the support for hydrogen evolution reaction (HER) and oxygen evolution reaction catalysts (OER) instead of copper foam (CF), nickel foam (NF), or carbon cloth (CC). Herein, the chemical plating method was used to create thin self-supporting electrodes based on cotton fiber filtration paper (FP). The Co-Ni-P amorphous nanospheres can be uniformly dispersed on the self-supporting FP due to its porous structure and oxygen functional groups. The Co-Ni-P/FP electrode has an overpotential as low as 125 mV for HER and 320 mV for OER at the current density of 10 mA cm−2. Additionally, according to density functional theory (DFT) calculations, the Co atom added to the Ni-P nanosphere can lead to considerably more charge accumulation around the Co and Ni active sites, which greatly encourages the HER and OER processes. The novel porous support, FP, provides a fresh way the preparation of self-supporting electrodes.

Control technologies to prevent aerosol-based disease transmission in animal agriculture production settings: a review of established and emerging approaches.

Transmission of infectious agents via aerosols is an ever-present concern in animal agriculture production settings, as the aerosol route to disease transmission can lead to difficult-to-control and costly diseases, such as porcine respiratory and reproductive syndrome virus and influenza A virus. It is increasingly necessary to implement control technologies to mitigate aerosol-based disease transmission. Here, we review currently utilized and prospective future aerosol control technologies to collect and potentially inactivate pathogens in aerosols, with an emphasis on technologies that can be incorporated into mechanically driven (forced air) ventilation systems to prevent aerosol-based disease spread from facility to facility. Broadly, we find that control technologies can be grouped into three categories: (1) currently implemented technologies; (2) scaled technologies used in industrial and medical settings; and (3) emerging technologies. Category (1) solely consists of fibrous filter media, which have been demonstrated to reduce the spread of PRRSV between swine production facilities. We review the mechanisms by which filters function and are rated (minimum efficiency reporting values). Category (2) consists of electrostatic precipitators (ESPs), used industrially to collect aerosol particles in higher flow rate systems, and ultraviolet C (UV-C) systems, used in medical settings to inactivate pathogens. Finally, category (3) consists of a variety of technologies, including ionization-based systems, microwaves, and those generating reactive oxygen species, often with the goal of pathogen inactivation in aerosols. As such technologies are typically first tested through varied means at the laboratory scale, we additionally review control technology testing techniques at various stages of development, from laboratory studies to field demonstration, and in doing so, suggest uniform testing and report standards are needed. Testing standards should consider the cost-benefit of implementing the technologies applicable to the livestock species of interest. Finally, we examine economic models for implementing aerosol control technologies, defining the collected infectious particles per unit energy demand.

ADVANCING THE UNDERSTANDING OF PM FILTER MASS STABILITY: UNVEILING THE INFLUENCE OF HUMIDITY AND TEMPERATURE

The intricate interplay between humidity and temperature on PM filter performance has remaineda subject of profound scientific interest. By employing fully-automated weighing method anda two-factor regression model, the study aimed to evaluate mass variations of unloaded PM filtersunder diverse humidity and temperature conditions. Existing guidelines, as posited by the USEPA and the European Standard (EN), have demonstrated a pronounced disparity. The US EPAadvocates a narrow humidity range of 30–40% RH, while the EN suggests a broader range of40–50% RH. The results of this investigation confirm the US EPA’s guidelines, which exhibitedsuperior filter mass stability under varying humidity. In controlled stable temperature conditionsof 20C, the research unveiled significant variations in filter mass as RH% increased from 50%to 55%. It has been proven that under stable temperature conditions (20C) inside a weighingrobot, an increase in relative air humidity from 50% to 55% results in filters mass addition by15 μg (Q, quartz fibre filters); by 93 μg (PTFE filters); by 9 μg (G, glass fibre filters); by 112 μg (PA,polyamide filters) and by 20 μg (PC, polycarbonate filters). Further exploration of the conditioningranges prescribed by the EN 12341:2014 standard, the study highlighted glass fibre filters as beingnotably stable, while polyamide membrane filters posed intriguing challenges potentially relatedto ionization insufficiencies during the equilibration stage. These findings bear significance forfilter manufacturing and conditioning protocols, potentially enhancing the precision of air qualitymonitoring practices.