Sorption of radium-226 from oil-production brine by sediments and soils

Abstract

The sorption of 226 Ra from oil-production brine by soils and sediments was investigated. Sorption was rapid, and the percentage sorbed increased with brine dilution. Greatest removals of 226 Ra from sediments in the laboratory occurred with alkaline DTPA, HCl, and BaCl 2, with lesser removals using CaCl 2 and NaCl solutions. Digestion of sediments with NaOCl indicates that most of the native and sorbed 226 Ra is associated with the mineral rather than organic fraction of the sediments. Correlation analysis based on 14 soils indicates that the retention of 226 Ra may involve precipitation reactions associated with sulfate-bearing minerals, as well as ion-exchange reactions with the clay mineral fractions of surficial earth materials. © 1982 Springer-Verlag New York Inc.