Effects of adsorbed water vapor on the adsorption rate constant and the kinetic adsorption capacity of the Wheeler kinetic model.

Details

• Personal Author:
  Breysse P ; Corn, Morton ; Hall T ; Jonas LA
• Description:
  The effect of adsorbed water vapor on the kinetic adsorption parameters of the Wheeler equation was investigated in order improve understanding of the effect of adsorbed water vapor on the effectiveness of respiratory protective devices used on the job. The adsorbates used were carbon-tetrachloride (56235) and triple distilled water; the adsorbent was activated-carbon. The Wheeler- Dubinin model was developed from a mass balance analysis of contaminant laden air passing through an adsorbent bed. The model rests on the assumption that a pseudo first order kinetic reaction occurs between the adsorbing molecules, the adsorbent and an unoccupied adsorption space. The water vapor-carbon isotherm derived indicated a significant hysteresis effect suggesting that once water vapor has been adsorbed onto the adsorbent, it is not desorbed readily. As the concentration of water vapor in the system was increased, the adsorption capacity decreased in a linear fashion when plotted against relative humidity. As the ability of the Wheeler-Dubinin Model to predict service life of a respirator cartridge is dependent on the accuracy of the Wheeler equation, it is significant to know that the adsorbed moisture had a profound effect on the parameters of this equation. The findings of this study indicate that when the relative humidity ranges from 60 to over 80 percent due to environmental conditions, the adsorbent bed is nearly saturated and maximum reductions in bed capacity should be anticipated. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Air Pollution, Indoor Occupational Health Personal Protective Equipment Respiratory Protective Devices Safety
• Keywords:
  Adsorbents Air-contamination Mathematical-models NIOSH-Grant NIOSH-Publication Personal-protective-equipment Respirators Respiratory-protective-equipment
• ISSN:
  0002-8894
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Maryland ; OSHA Region 3
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  461-465
• Volume:
  49
• Issue:
  9
• NIOSHTIC Number:
  nn:00181936
• Citation:
  Am Ind Hyg Assoc J 1988 Sep; 49(9):461-465
• Contact Point Address:
  Environmental Health Sciences Johns Hopkins University 615 North Wolfe Street Baltimore, MD 21205
• CAS Registry Number:
  Carbon tetrachloride (CAS RN 56-23-5)
• Federal Fiscal Year:
  1988
• NORA Priority Area:
  Respirators Research
• Performing Organization:
  Johns Hopkins University, Baltimore, Maryland
• Peer Reviewed:
  True
• Start Date:
  19830923
• Source Full Name:
  American Industrial Hygiene Association Journal
• End Date:
  19890630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:e54d8a408d371feea264637fa765284f82e13ecc8f477b6cd952efdf377f061f23b1e415d45dfa1765283b0ce211904b5b741968d24d45750330ce34b2015392
• Download URL:
  https://stacks.cdc.gov/view/cdc/185621/cdc_185621_DS1.pdf
• File Type:
  [PDF - 396.11 KB ]