Soda ash treatment of a strontium-90-contaminated groundwater seep
A /sup 90/Sr-contaminated groundwater seep on the perimeter of a low-level radioactive solid waste disposal area at the Oak Ridge National Laboratory (ORNL) was treated by burying 315 kg of soda ash in the groundwater flow path leading to the seep, and placing 45 kg of soda ash on the surface of the seep. The concentration of /sup 90/Sr in the seep water fell from an average of 7000 Bq L/sup -1/ to 900 Bq L/sup -1/ for the 90 d after burial, followed by a period of gradual rise back to pretreatment levels over the next 100 d. The electrical conductivity and pH of the seep water increased following soda ash burial, while water hardness fell. Hardness was highly correlated (r = 0.84) with /sup 90/Sr concentrations over the entire 2-year observation period, indicating the similar behavior of /sup 90/Sr and soluble Ca and Mg. This in situ softening of, and /sup 90/Sr precipitation from, the seep water was achieved by coprecipitation of /sup 90/Sr with Ca(Mg)CO/sub 3/ until the buried soda ash was depleted by dissolution in the groundwater. The soda ash treatment of groundwater seeps appears to be most practical as an interim technique for those situations requiring an immediate, but temporary, corrective action. During this limited but effective period, more permanent corrective actions could be planned at the source of contamination. The electrical conductivity, pH, and hardness of the larger surface stream, into which this seep discharges, were not affected by the soda ash burial, most likely due to the approximately 2000-fold dilution effected by this stream.
- Research Organization:
- Oak Ridge National Lab., TN
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5042972
- Journal Information:
- J. Environ. Qual.; (United States), Vol. 12:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
58 GEOSCIENCES
GROUND WATER
CONTAMINATION
DECONTAMINATION
SODIUM CARBONATES
PRECIPITATION
STRONTIUM 90
RADIOECOLOGICAL CONCENTRATION
ELECTRIC CONDUCTIVITY
EXPERIMENTAL DATA
PH VALUE
RADIOACTIVE WASTES
USES
ALKALI METAL COMPOUNDS
ALKALINE EARTH ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON COMPOUNDS
CARBONATES
CLEANING
DATA
ECOLOGICAL CONCENTRATION
ELECTRICAL PROPERTIES
EVEN-EVEN NUCLEI
HYDROGEN COMPOUNDS
INFORMATION
INTERMEDIATE MASS NUCLEI
ISOTOPES
MATERIALS
NUCLEI
NUMERICAL DATA
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIOACTIVE MATERIALS
RADIOISOTOPES
SEPARATION PROCESSES
SODIUM COMPOUNDS
STRONTIUM ISOTOPES
WASTES
WATER
YEARS LIVING RADIOISOTOPES
520300* - Environment
Aquatic- Radioactive Materials Monitoring & Transport- (1989)
580400 - Geochemistry- (-1989)