Methyl iodide retention on charcoal sorbents at parts-per-million concentrations

Conference · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6698869

Wood, G O; Vogt, G J; Kasunic, C A

Breakthrough curves for charcoal beds challenged by air containing parts-per-million methyl iodide (/sup 127/I) vapor concentrations were obtained and analyzed. A goal of this research is to determine if sorbent tests at relatively high vapor concentrations give data that can be extrapolated many orders of magnitude to the region of interest for radioiodine retention and removal. Another objective is to identify and characterize parameters that are critical to the performance of a charcoal bed in a respirator cartridge application. Towards these ends, a sorbent test system was built that allows experimental variations of the parameters of challenge vapor concentration, volumetric flow rate, bed depth, bed diameter, and relative humidity. Methyl iodide breakthrough was measured at a limit of 0.002 ppM using a gas chromatograph equipped with a linearized electron capture detector. Several models that have been proposed to describe breakthrough curves were tested against experimental data. A variety of charcoals used or proposed for use in radioiodine air filtration systems have been tested against 25.7 ppM methyl iodide to obtain these parameters and protection (decomtamination) factors. Effects of challenge concentration, relative humidity, and bed diameter were also investigated. Significant challenge concentration dependence was measured (more efficiency at lower concentration) for two types of charcoals. Increased relative humidity greatly decreased breakthrough times for a given protection factor. Increased bed diameter greatly increased breakthrough times for a given protection factor. Implications of these effects for a test method are discussed.

• Research Organization: Los Alamos Scientific Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6698869
• Report Number(s): LA-UR-78-1913; CONF-780819-8
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420202* -- Engineering-- Protective Structures & Equipment
ADSORBENTS
ADSORPTION
AIR FILTERS
CHARCOAL
EQUIPMENT
FILTERS
HALOGENATED ALIPHATIC HYDROCARBONS
IODINATED ALIPHATIC HYDROCARBONS
METHYL IODIDE
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PERFORMANCE TESTING
POLLUTION CONTROL EQUIPMENT
RESPIRATORS
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
TESTING