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Adsorption of vapor mixtures onto activated carbon.
Department of Environmental Health Sciences, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 1994 Sep; :1-97
A method was developed for the study of the adsorption of one vapor in a mixture onto activated-carbon for use in the estimation of organic vapor respirator service life. It was possible to study the absorption of one vapor in the presence of a second vapor using methods developed with a dual flame ionization detector/photoionization detector without any interference from the second vapor. The Wheeler and Dubinin models were used to study the potential effect of the polarity of a vapor on the adsorption of a polar or a nonpolar vapor. The polarity of the accompanying vapor did not systematically affect the Wheeler model 1% breakthrough. The polarity of the vapor did not systematically affect the Test vapor Wheeler model adsorption capacity. The Wheeler model adsorption rate constants for Test vapors were not significantly different when compared according to Probe vapor polarity. The polarity of the probe vapor appeared to subtly affect the affinity of p-xylene (1330207) as determined by the Dubinin model. In the presence of polar and lower boiling point compounds, p-xylene appeared to have greater affinity for carbon than when in the presence of nonpolar higher boiling point compounds. The authors suggest that it may be possible to estimate the service life of a respirator for a vapor in a mixture using the carbon capacity for the vapor, and the mole fraction of the vapor in the mixture. Errors of 30% or more can be expected for vapors in the ranges of polarity, boiling point, and concentration tested.
NIOSH-Grant; Respirators; Respiratory-protective-equipment; Organic-vapors; Adsorbents; Chemical-properties
Environmental Health Sciences Johns Hopkins University 615 North Wolfe Street Baltimore, MD 21205
Final Grant Report
NTIS Accession No.
Department of Environmental Health Sciences, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland
Johns Hopkins University, Baltimore, Maryland
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