Determination of irreversible absorption of water by cellulose filters

Demuynck, M.

doi:10.1016/0004-6981(75)90113-4

Cited by 13 publications

(5 citation statements)

References 5 publications

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“…Tierney and Conner (1967) concluded that the effect of relative humidity (RH) on glass fibre filters was insignificant, but at RH > 55 % the effect on collected particulates was significant. Demuynck (1975) demonstrated that during 1 h high volume sampling in an urban area on a foggy day the amount of water irreversibly retained by cellulose filters is comparable to or even higher than the mass of particulate matter collected. Brown et al (2006) compared the behaviour of quartz fibre, glass fibre and PTFE-bonded glass fibre under different RH conditions and found that the deviation in mass of certain unexposed 47 mm filters exceeded 450 µg while the RH ranged between 30 and 81 %.…”

Section: Introductionmentioning

confidence: 97%

Bias caused by water adsorption in hourly PM measurements

et al. 2017

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Abstract. Beta-attenuation monitors are used worldwide to monitor PM mass concentration with high temporal resolution. Hourly PM10 and PM2. 5 dry mass concentrations are publicly available with the tacit assumption that water is effectively removed prior to the measurement. However, as both the filter material of the monitor and the aerosol particles are capable of retaining a significant amount of water even at low relative humidities, the basic assumption may not be valid, resulting in significant bias in reported PM10 and PM2. 5 concentrations. Here we show that in PM10 measurement, particle-free air can produce apparent hourly average PM concentrations in the range of −13–+21 µg m−3 under conditions of fluctuating relative humidity. Positive and negative apparent readings are observed with increasing and decreasing relative humidities, respectively. Similar phenomena have been observed when the instrument filter was previously loaded with atmospheric aerosol. As a result the potential measurement biases in hourly readings arising from the interaction with water may be in the range of −53… + 69 %.

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Section: Introductionmentioning

confidence: 97%

Bias caused by water adsorption in hourly PM measurements

et al. 2017

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“…Tierney and Conner () concluded that the effect of RH on glass fiber filters was insignificant, but at RH > 55% the effect on collected particulates was significant. Demuynck () demonstrated that the amount of water irreversibly retained by cellulose filters is comparable to or even higher than the mass of particulate matter collected during the foggy day. In addition, the particulate mass collected in 1 hr is small; thus, the bias caused by water may be excessive.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

“…Tierney and Conner (1967) concluded that the effect of RH on glass fiber filters was insignificant, but at RH > 55% the effect on collected particulates was significant. Demuynck (1975) demonstrated that the amount of water irreversibly retained by cellulose filters is comparable to or even higher than the mass of particulate matter 10.1029/2018JD029269…”

Section: Journal Of Geophysical Research: Atmospheresmentioning

confidence: 99%

The Effects of PM_2.5 Concentrations and Relative Humidity on Atmospheric Visibility in Beijing

2019

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Atmospheric visibility is often used as a proxy for ambient air quality. However, in addition to the concentrations of particulate matter, visibility is also affected by meteorological conditions. The relative contributions of PM2.5 concentrations and meteorological conditions to visibility are not yet clear. In this study, the individual contributions of PM2.5 concentrations and the relative humidity (RH) to the visibility are measured based on observations at 12 stations in Beijing. We find that visibility decreases quickly as PM2.5 concentrations increase at clean condition and decreases slowly when PM2.5 concentrations exceed 100 μg/m3. The visibility decreases linearly as PM2.5 concentrations increase when PM2.5 concentrations lower than 50 μg/m3; however, there tends to be an exponential relationship as PM2.5 concentrations increase. The PM2.5 concentrations can explain 50% of the variance in visibility in clean and high‐humidity environments, whereas this fraction decreases to 10–15% when the PM2.5 concentrations exceed 200 μg/m3. In contrast, RH has little effect on visibility under dry conditions. When the RH exceeds 40%, atmospheric visibility tends to display an inversely proportional and exponential relationship with RH under polluted and clean conditions, respectively. Under high‐humidity and highly polluted conditions, up to 40% of the variance in visibility is associated with RH. The PM2.5 concentrations dominate the variations in visibility under dry or low PM2.5 concentrations, and the contributions of RH become increasingly important as PM2.5 concentrations and humidity increase. The difference of aerosol types and weather conditions increase the uncertainties of correlation coefficients between visibility and PM2.5/RH. This study emphasizes the atmospheric conditions when employing visibility as a proxy for air pollution.

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“…As this material is carbon-based, these filters are inappropriate for carbon analysis. Cellulose-fiber filters have low and variable filtration efficiency (~70%) [ 92 ] and they absorb water, which can cause filter-weighing biases unless the balance environment maintains a constant relative humidity (RH) [ 93 ]. These filters are best used for absorbing gases after being impregnated with acid or base solutions.…”

Section: Filter Characteristicsmentioning

confidence: 99%

Review of Filters for Air Sampling and Chemical Analysis in Mining Workplaces

et al. 2022

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This review considers the use of filters to sample air in mining workplace environments for dust concentration measurement and subsequent analysis of hazardous contaminants, especially respirable crystalline silica (RCS) on filters compatible with wearable personal dust monitors (PDM). The review summarizes filter vendors, sizes, costs, chemical and physical properties, and information available on filter modeling, laboratory testing, and field performance. Filter media testing and selection should consider the characteristics required for mass by gravimetry in addition to RCS quantification by Fourier-transform infrared (FTIR) or Raman spectroscopic analysis. For mass determination, the filters need to have high filtration efficiency (≥99% for the most penetrable particle sizes) and a reasonable pressure drop (up to 16.7 kPa) to accommodate high dust loading. Additional requirements include: negligible uptake of water vapor and gaseous volatile compounds; adequate particle adhesion as a function of particle loading; sufficient particle loading capacity to form a stable particle deposit layer during sampling in wet and dusty environments; mechanical strength to withstand vibrations and pressure drops across the filter; and appropriate filter mass compatible with the tapered element oscillating microbalance. FTIR and Raman measurements require filters to be free of spectral interference. Furthermore, because the irradiated area does not completely cover the sample deposit, particles should be uniformly deposited on the filter.

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Determination of irreversible absorption of water by cellulose filters

Cited by 13 publications

References 5 publications

Bias caused by water adsorption in hourly PM measurements

Bias caused by water adsorption in hourly PM measurements

The Effects of PM_2.5 Concentrations and Relative Humidity on Atmospheric Visibility in Beijing

Review of Filters for Air Sampling and Chemical Analysis in Mining Workplaces

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Determination of irreversible absorption of water by cellulose filters

Cited by 13 publications

References 5 publications

Bias caused by water adsorption in hourly PM measurements

Bias caused by water adsorption in hourly PM measurements

The Effects of PM2.5 Concentrations and Relative Humidity on Atmospheric Visibility in Beijing

Review of Filters for Air Sampling and Chemical Analysis in Mining Workplaces

Contact Info

Product

Resources

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The Effects of PM_2.5 Concentrations and Relative Humidity on Atmospheric Visibility in Beijing