A Comparison of Sorption Coefficients Determined by Batch, Column, and Box Methods on a Low Organic Carbon Aquifer Material

Results of three independent experimental methods for determination of sorption coefficients were compared on sieved aquifer material samples from Columbus AFB, Columbus, Mississippi. These aquifer materials contained <0.1% organiccarbon, and sorption coefficients for naphthalene ranged from 0.06 to 0.20 I/kg. There was low correlation between organic carbon contents and sorption coefficients. Good agreement was found among sorption coefficients measured by batch, dynamic column, and dynamic box methods. Similarity of the coefficients was attributed to measured fast sorption kinetics and to linearity of isotherms observed for naphthalene sorption on Columbus aquifer material. Results indicate that channeling, wall and end effects, and particle loss were insignificant in the dynamic systems. Since laboratory sorption coefficient measurements were found impractical on whole sand-gravel aquifer samples, an equation is proposed to convert laboratory measured sorption coefficients on the separated sand (<2 mm) fraction to sorption coefficients on wholesand-gravel aquifer materials.