Carbon aging mechanisms and effects on retention of organic iodides

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6140632

Hyder, M L

The activated carbon used to treat the off-gas from the Savannah River Plant prodution reactor building was studied to determine the chemical changes occurring in this carbon during its service life. The carbon is a coconut-shell charcoal impregnated with 1% triethylenediamine (TEDA) and 2% KI. It was known that during its 30-month service life the carbon becomes more acidic and less effective for retaining iodine in organic form. The study showed that the most important change occurring in the carbon is the reaction of KI to give other chemical forms of iodine. The reacted iodine is unavailable for exchange with alkyl iodides. The results suggest that the carbon reacts with KI to form organic compounds, but small amounts of oxidized iodine may also be presnt. There is also evidence that some iodide is lost from the carbon altogether. The TEDA impregnant is lost from the carbon very quickly, and has no importance after a few months. The specific reactions by which the impregnant is lost have not been identified. However, mathematical analysis shows that the carbon performance data are consistent with the reaction of iodide impregnant with impurities in the air flowing through the carbon bed. Additional mathematical analysis, based on electron microscopic observation of the carbon particles, indicates that the external surfaces of the carbon are mainly responsible for their effectiveness in retaining iodine. Consequently, the condition of the impregnants on a relatively small fraction of the carbon surface can have a large effect on its performance. 4 refs., 14 figs., 2 tabs.

• Research Organization: Savannah River Lab., Aiken, SC (USA)
• DOE Contract Number: AC09-76SR00001
• OSTI ID: 6140632
• Report Number(s): DP-MS-85-22; CONF-8510264-1; ON: DE86004617
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
500300* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACTIVATED CARBON
ADSORBENTS
ALKALI METAL COMPOUNDS
CARBON
CHEMICAL REACTIONS
DECOMPOSITION
ELECTRON MICROSCOPY
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
INORGANIC PHOSPHORS
IODIDES
IODINE COMPOUNDS
IODINE ISOTOPES
ISOTOPES
MANAGEMENT
MICROSCOPY
NATIONAL ORGANIZATIONS
NONMETALS
PHOSPHORS
POTASSIUM COMPOUNDS
POTASSIUM IODIDES
REACTORS
SAVANNAH RIVER PLANT
STACK DISPOSAL
US AEC
US DOE
US ERDA
US ORGANIZATIONS
WASTE DISPOSAL
WASTE MANAGEMENT