Pollutant Control by Electric Methods

Modern era has witnessed particulate matter (PM) become one of the biggest threats for the existence of biological species. Therefore, a study was performed in Faisalabad city to evaluate PM retention and removal efficiency of ten local tree species. Branch samples were collected from urban, sub-urban and rural areas in September 2020 (183 days after rain), and in August 2021 (30 days after rain). Results showed that total PM load, PM>10 and PM10-2.5 retention was the highest in urban followed by sub-urban and rural area. PM>10, PM10-2.5, total PM, and PM deposition rate decreased significantly in the following order, F. benghalensis > T. arjuna > S. cumini > A. scholaris > F. religiosa > E. camaldulensis > D sissoo > C lancifolius > B. ceiba > M. alba during both years 2020, and 2021. During the artificial rainfall experiment, total PM removed by the species also followed the same order however, PM removal efficiency was the highest in B. ceiba and M. alba followed by E. camaldulensis, C. lancifolius, D. sissoo, T. arjuna, S. cumini, A. scholaris, F. religiosa and F. benghalensis. Therefore, it can be concluded that species selection must be done skillfully for congested urban environment.

The main objective of this research is to synthesize silk fibroin fiber for indoor air particulate removal. Silk cocoons were de-gummed using 0.5 wt % Na₂CO₃. In this work, the morphologies, physical properties, and mechanical properties of the SF fiber were studied Three sets of experiment were conducted to investigate the impacts of air flow rate, initial particulate matter (PM) concentration, and that of filter types on the PM removal efficiency. Rice bran collected from a local rice mill in Ubonratchathani province was used as indoor air contaminant in this work. The SEM revealed the deposition of PM on the used fiber. The pore size of the SF fiber was estimated to be 24.664 ± 0.005 Å and was classified as mesopore. The mechanical property of 0.024±0.008 N/mm² was obtained of the SF fiber. The maximum PM removal efficiencies of 70.39±0.68 % and 37.85 ± 3.04 % were obtained of PM₁₀ and PM[subscript 2.5], respectively, when using air flow rate of 5 L/min. When the initial PM concentrations of PM10 and PM[subscript 2.5] were increased to 2, 3, 4, and 5 times of the original concentrations, The highest PM₁₀ removal efficiencies of 70.39±0.68 % was obtained when using initial concentration at 0.040 mg/m³. The highest PM[subscript 2.5] removal efficiency of 57.26±3.36 % was obtained when using initial concentration at 0.080 mg/m³. The effects of different filter types were also included in this study. The results show that the 3M-8210 fiber yielded the highest PM removal efficiency as compared to the SF fiber. However, the SF fiber costs about eleven times less than the 3M-8210. Therefore, the SF fiber could be applied as an alternative material for indoor air treatment.

Nonthermal plasma (NTP) treatment of exhaust gas is a promising technology for both nitrogen oxides (NOX) and particulate matter (PM) reduction by introducing plasma into the exhaust gases. This paper considers the effect of NTP on PM mass reduction, PM size distribution, and PM removal efficiency. The experiments are performed on real exhaust gases from a diesel engine. The NTP is generated by applying high-voltage pulses using a pulsed power supply across a dielectric barrier discharge (DBD) reactor. The effects of the applied high-voltage pulses up to 19.44 kVpp with repetition rate of 10 kHz are investigated. In this paper, it is shown that the PM removal and PM size distribution need to be considered both together, as it is possible to achieve high PM removal efficiency with undesirable increase in the number of small particles. Regarding these two important factors, in this paper, 17 kVpp voltage level is determined to be an optimum point for the given configuration. Moreover, particles deposition on the surface of the DBD reactor is found to be a significant phenomenon, which should be considered in all plasma PM removal tests.

Grilling restaurants are a major contributor to airborne particulate matter (PM) in metropolitan areas. In this study, the removal of PM during the grilling of pork belly using an orifice scrubber, which is a form of gas-induced spray scrubber, was assessed. During grilling, the particle mass concentration was the highest for 1.0 < PM ≤ 2.5 μm (55.5% of total PM emissions), followed by 0.5 < PM ≤ 1.0 (27.1%), PM ≤ 0.5 (10.7%), and PM > 2.5 μm (7.0%). The PM removal efficiency of the orifice scrubber at a gas flow of 4.5 m3 min−1 was > 99.7% for PM ≥ 2.5 μm, 89.4% for 1.0 < PM ≤ 2.5 μm, 62.1% for 0.5 < PM ≤ 1.0, and 36.5% for PM ≤ 0.5 μm. Although further research is necessary to optimize its use, the orifice scrubber offers a user-friendly technology for the control of PM in small grilling restaurants because of its simple design, uncomplicated operation, and satisfactory PM removal performance.

Application of DBD air plasma for indoor particulate matter removal

A new swirl combustion device was designed and enhanced, which realized the utilization of steel slag, achieved highly efficient and clean coal combustion, and simultaneously realized a fully elemental utilization of coal. The distribution laws of different sized particulate matter (PM) emission and the enrichment laws of elements in particles under diverse conditions (such as various excess air coefficients and different coal ratios) were systematically studied. The enrichments of PM under both non-staged and fuel-staged conditions were also investigated. The results indicated that fuel-staged combustion is more helpful in reducing PM emissions than non-staged combustion, and a suitable coal ratio is also beneficial for reducing PM emissions. The melted liquid steel slag drop captured the fly ash produced from pulverized combustion, thus reducing PM emission. The alkali metal elements (K, Na, and Mg), the trace elements (As and Ti), and S have an obvious enrichment tendency in PM1 and PM2.5. A different coal ratio under fuel-staged combustion has a significant influence on the enrichment of Al, Si, Ca, and Fe in PM1, whereas in PM2.5, PM4, and PM10, the effect of different coal ratios on the enrichment of each element is slight.

In this study, results of an extensive set of experiments on a wood pellet stove model equipped with innovative burning pots are presented. Tests have been performed to investigate the relations between design data and operation parameters of the stove and its emissions. In particular, carbon monoxide (CO) and particulate matter (PM) emissions are correlated to the burning-pot depth.The burning pot A, adopted by AICO S.p.A, allows to obtain near-to-zero CO emissions and low PM emissions: however, PM emissions reduction with respect to standard burning pots is not as enhanced as CO emission reduction. Here it is shown that a further reduction of PM emissions (down to 6-16 mg/Nm3) can be attained increasing the burning pot depth.Experiments show also an increment of PM emissions in subsequent tests in the same day: there is an apparent dependence of PM release on the time from ignition. It is likely that this effect is due to ashes accumulation on the bottom of the burning pot and to their interaction with the primary air stream that flows over them.

This study investigated the impact of Emission Control Systems (ECS) on Particulate Matter (PM) emissions from two major industrial sectors in Lahore i.e boilers and steel induction furnaces. Data was collected from 2020 to 2024 to assess the effectiveness of the Environmental Protection Agency's (EPA) efforts in promoting and enforcing ECS installation. PM emissions were monitored using isokinetic sampling methods for both units equipped with ECS (Wet Scrubbers for boilers and predominantly Dry Scrubbers for steel furnaces) and those operating without ECS. The data demonstrated a significant reduction in PM emissions from both sources. The steel industry with 71 units in Lahore, the number of units operating without ECS decreased dramatically from 69 in 2021 to just 1 in 2024, leading to a 49% drop in emissions. Similarly, in the boiler sector, the installation of Wet Scrubbers on 540 out of 600 boilers resulted in a 25% reduction in PM emissions between 2021 and 2024. The study highlighted the effectiveness EPA mitigation measures to control pollution and ensuring cleaner air for the region

This study investigated the impact of Emission Control Systems (ECS) on Particulate Matter (PM) emissions from two major industrial sectors in Lahore i.e boilers and steel induction furnaces. Data was collected from 2020 to 2024 to assess the effectiveness of the Environmental Protection Agency's (EPA) efforts in promoting and enforcing ECS installation. PM emissions were monitored using isokinetic sampling methods for both units equipped with ECS (Wet Scrubbers for boilers and predominantly Dry Scrubbers for steel furnaces) and those operating without ECS. The data demonstrated a significant reduction in PM emissions from both sources. The steel industry with 71 units in Lahore, the number of units operating without ECS decreased dramatically from 69 in 2021 to just 1 in 2024, leading to a 49% drop in emissions. Similarly, in the boiler sector, the installation of Wet Scrubbers on 540 out of 600 boilers resulted in a 25% reduction in PM emissions between 2021 and 2024. The study highlighted the effectiveness EPA mitigation measures to control pollution and ensuring cleaner air for the region

Particulate matter (PM) is one of the most hazardous atmospheric pollutants. Several plant species show high potential to reduce air pollutants and are widely used as green belts to provide clean outdoor spaces for human well-being. However, high PM concentrations cause physiological changes and stress in plants. In this study, 11 species of Thai native perennial plants were exposed to PM generated from tobacco smoke. Wrightia religiosa (Teijsm. & Binn.) Benth. ex Kurz, Bauhinia purpurea DC. ex Walp. and Tectona grandis L.f. reduced PM effectively (which is in the typical range of 43.95 to 52.97%) compared to other plant species. In addition, the responses of perennial plants under PM stress at the proteomic level were also evaluated. Proteomic analysis of these three plant species showed that plants respond negatively to high PM concentrations, such as reducing several photosynthetic-related proteins and increasing plant stress response proteins. To improve PM phytoremediation efficiency and reduce plant stress from PM, perennial plant-microbe interactions were investigated. W. religiosa was inoculated with Acinetobacter indicus PS1, and high biosurfactant-producing strains clearly showed a higher PM removal efficiency than non-inoculated plants (9.48, 9.5 and 12.6% for PM1.0, PM2.5 and PM10, respectively). Inoculating W. religiosa with A. indicus PS1 maintained chlorophyll a and b concentrations. Moreover, the malondialdehyde (MDA) concentration of W. religiosa inoculated with A. indicus PS1 was lower than that of non-inoculated W. religiosa. The leaf wax content (µg/cm2) and biosurfactant (µg/cm2) of W. religiosa inoculated with A. indicus PS1 were also higher than those of non-inoculated W. religiosa. This study clearly showed that inoculating plants with A. indicus PS1 can help plants remediate PM and improve their PM stress response.

A porous gradient geopolymer-based tube membrane with high PM removal rate for air pollution

HighlightsAnnual average PM10 (daily) and PM2.5 (hourly) concentrations of 509 ±203 and 43.3 ±36.1 µg m-3, respectively.Significant seasonal and diurnal variations in PM concentrations; higher in colder seasons and during daytime.Annual average PM10 (daily) and PM2.5 (hourly) emission rates of 17.9 ±9.6 and 1.41 ±1.53 mg d-1 hen-1, respectively.Significant diurnal variations in PM emission rates but inconsistent seasonal variations; higher during daytime.Abstract. Particulate matter (PM) concentration and emission rate information is needed to assess air quality concerns and environmental impacts related to egg production. Many egg layer buildings were retrofitted from high-rise to manure-belt houses over the past few decades. However, no studies have reported these PM data for the retrofitted layer houses. In this study, concentrations and emission rates of PM10 and PM2.5 were continuously monitored for 12 months at two commercial retrofitted manure-belt layer houses in the Midwestern U.S. The average daily mean PM10 and average hourly mean PM2.5 concentrations in the houses were 509 ±203 µg m-3 and 43.3 ±36.1 µg m-3, respectively. Significant seasonal and diurnal variations in PM concentrations were observed, with higher concentrations in colder seasons and during daytime. The average daily mean PM10 and average hourly mean PM2.5 emission rates from the two houses were 17.9 ±9.6 mg d-1 hen-1 and 1.41 ±1.53 mg d-1 hen-1, respectively. There were no consistent patterns in seasonal variations. Significant diurnal variations were also observed for PM emission rates, with higher PM emission rates observed during daytime. The PM concentrations were significantly correlated with ambient temperature, ventilation rate, bird age, egg production, daily mortality, and feed conversion ratio, while PM emission rates were significantly correlated with ambient temperature, bird age, bird mass, egg mass, and ventilation rate. Keywords: Diurnal variation, Dust, Egg production, PM, Poultry, Seasonal variation.

Tires generally wear out due to the friction between the tire and the road surface. Minimizing tire wear could reduce the non-exhaust particulate matter (PM) emissions from tires. Typically, tire treadwear grade can be used as an indicator of PM emissions from tires. Tires that wear out quickly will produce higher PM emissions than more durable tires. In this study, the effect of treadwear grade on the generation of tire PM emissions was investigated through laboratory and on-road driving measurements. In the laboratory measurements, a tire wear simulator installed in an enclosed chamber was used to eliminate artifacts caused by interfering particles during the generation and measurement of tire wear particles. For realistic on-road driving measurements, a mobile sampling vehicle was employed to sample road dust. The road dust was chemically analyzed using pyrolysis gas chromatography–mass spectrometry (GC–MS) to characterize the tire-road wear particles.Both measurements showed that the higher treadwear grade generated lower tire PM emissions due to the high strength of the rubber, except for the UTQG 700 tire. The UTQG 700 tire, which had the highest treadwear grade, produced higher PM emissions than the UTQG 350 and 500 tires because it readily formed the fine particles due to lamellar peeling rather than tearing or curling of tire treads. Notably, tire nanoparticles were observed in laboratory measurements due to the volatilization and nucleation of the sulphur (S) and zinc (Zn) compounds in the tire tread due to the frictional heat between the tire and paved road surface.

Effect of water microdroplet size on the removal of indoor particulate matter

Although the big tobacco companies offer the same cigarette brands across countries, little is known about the potential regional differences of the particulate matter (PM) emissions of apparently equal brands. PM emissions of three cigarette brands (Marlboro Gold, Winston Red resp. Classic, Parliament Platinum resp. Night Blue) from the United Arab Emirates (UAE) and Germany were analysed. Second-hand smoke was produced in a 2.88 m3 measuring cabin by an automatic environmental tobacco smoke emitter. PM size fractions PM10, PM2.5, and PM1 were detected in real-time using laser aerosol spectrometry. Depending on the PM fraction Marlboro cigarettes from UAE showed 33%–35% higher PM amounts. Moreover, Winston cigarettes from UAE showed distinctly higher PM values (28–31%) than the German counterparts. The “lighter” Parliament from UAE emitted 3%–9% more PM than the German one. The measured mean PM10 values laid between 778 and 1163 µg/m3 (mean PM2.5: 777–1161 µg/m3; mean PM1: 724–1074 µg/m3). That means smoking in enclosed rooms causes massive PM burden. The PM emission of equal or similar tobacco products from different countries can differ distinctly. Hence, the declaration of PM emission values, besides nicotine, tar, and carbon monoxide amounts, should be obligatory worldwide. Furthermore, complete information about the ingredients and production processes of tobacco products should be provided to health officials and the public. This can help to minimise or ban substances or product designs that make smoking even more harmful, and to enhance the awareness of the risks of smoking.