Identification of cement in atmospheric particulate matter using the hybrid method of laser diffraction analysis and Raman spectroscopy

Use of hybrid filters to optimize the process of the filtration in cement particles

Due to growing concern about air pollution and its harmful effects on the health of the population, especially in regard to sub-micrometric particles, some studies have reported that applying an electric field to particle suspensions can improve filter performance by enhancing the deposition of particles in the filter medium. This can result in better particulate retention, which is particularly important for industrial processes such as cement production. The objective of this study was to investigate the behavior of cement particles with electrostatic charges during cake formation in fabric filters. The particles (with a d50 % of 17 μm) were generated using a dust feeder at a flow rate of 0.083 kg s-1. The fiberglass filter medium was subjected to filtration tests with constant dust concentrations (9-12 g.m-³) and air surface velocities (6 cm.s-1and 10 cm s-1) until the pressure drop reached the maximum value of 400 Pa. The electrostatic precipitator utilized discharge voltages of 0, 4, 10, and 12 kV. The particles were initially passed through the electrostatic precipitator to become charged with voltages of 0, 4, 10, and 12 kV applied. The results indicated a reduction in pressure drop of up to 55 %. The study observed a change in the deposition behavior of particles on the filter medium surface and in the filter cake formation, demonstrating that the electrostatic charge improves air filtration performance, resulting in higher efficiency and cost-effectiveness.

The Study of Airborne Particulate Matter in Dalnegorsk Town

Mines, quarries, dumps, and tailings are the sources of air pollution. In the Dalnegorsk District (Primorsky Krai, Russia), there are 20 polymetallic deposits. This study aimed to evaluate the particle size and material composition of ambient particulate matter (PM) in Dalnegorsk town and verify the influence of mining and chemical industry facilities on the composition of PM. Ambient particulates were analyzed in samples of snow cover and washout from vegetation (conifer tree needles). According to particle size distribution data, the relative content of particles with a diameter up to 10 microns (PM₁₀) reaches 40% in three snow samples taken in the central part of the town. Among ore minerals, pyrite and arsenopyrite predominated in the samples. In addition, sphalerite, galena, cassiterite, and iron–chromium–nickel formations of various shapes were found in the studied particles. The presence of these metals in airborne PM can negatively affect the incidence rate of PM-associated diseases and the determination of their levels are very useful for air pollution prevention strategies.

Using Ultrasound-Treated Washout from Conifer Needles and Fresh Snow Samples in Air Pollution Monitoring

Snow precipitation and snowpack are commonly used to assess the condition of the aerial environment. Another way to monitor air quality is to study trees and shrubs, which are natural barriers for capturing air pollution, including atmospheric particulate matter. The hypothesis of the current study was that using fresh snow precipitation and washout from vegetation for the monitoring of air pollution can produce comparable results. In this study, we compared the results of laser diffraction analysis of suspended particular matter in melted fresh snow and ultrasound-treated washout from conifer needles. The samples were collected at several sites in Primorsky Krai, Russian Federation, and analyzed according to the same scheme. We observed that the content of particulate matter with a smaller aerodynamic diameter in the ultrasound-treated washout from conifer needles was higher than that in the melted fresh snow. The content of PM₁₀ in the ultrasound-treated washout from conifers was increased by 6–27% depending on the site, showing greater efficacy of this method. This method can be used as an alternative to the sampling of snow for the monitoring of ambient air pollution, taking into account several limitations.