SREL Reprint #2674

Distribution Patterns of Native Sulfate Displaced by Respective Pore Volumes of Oxalic Acid in Cecil Bt Soil

Bon-Jun Koo1, Doug Y. Chung2, and Jae E. Yang3

1Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802, USA
2Department of Agricultural Chemistry, Chungnam National University, Daejeon 305-764, Korea
3Department of Bioenvironmental Chemistry, Kangwon National University, Chunchun 200-701, Korea

Abstract: In this investigation we tried to investigate the effect of oxalic acid on the fate of native sulfate in Bt soil that contained a high kaolinitic clay by observing the distribution of two anions using soil column under the given competitive adsorption between displaced and displacing anions. To do this the soil columns uniformly packed to a bulk density of 1.25 g/cm3 with Cecil Bt soil were disected and analyzed the amounts of sulfate and oxalic acid both in solution and solid phases after flowing the designated pore volumes of oxalic acid. The results showed that two sets of curves-nonlinear (> 10-3 M) and linear (< 10-3 M) curves where the solution of oxalic acid was not adjusted, while the approaches to the plateau were slow when pH of oxalic acid was adjusted to 5. The cumulative amount of sulfate desorbed by successive addition of oxalic acid was nonlinearly approached to the plateau at the concentration of 10-3 M or greater, indicating that the number of addition of oxalic acid increased mth decreasing order of oxalic acid. However, the plateau did not obtain where the concentration of oxalic acid were less than 10-4 M showing a linear increase. Therefore, we may conclude that the rate-limited desorption was involved as the concentration of oxalic acid decreased.

Keywords: Bt soil, oxalic acid, pore volume, sulfate.

SREL Reprint #2674

Koo, Bon-Jun, D. Y. Chung, and J. E. Yang. 2002. Distribution patterns of native sulfate displaced by respective pore volumes of oxalic acid in cecil Bt soil. Korean Journal of Environmental Agriculture 21:291-296.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).