Abstract |
This report presents metal adsorption distribution coefficients (K values) for the metals barium (Ba), beryllium (Be), cadmium (Cd), chromium(III) (Cr(III)), and lead (Pb) in groundwater under the highly alkaline conditions possible with land disposal of cement kiln dust (CKD). K is the ratio of concentration sorbed to concentration in the dissolved phase at d equilibrium. The K values were determined using the U.S. EPA geochemical speciation model, d MINTEQA2. The above mentioned metals along with antimony, arsenic, chromium(VI), and thallium were the subject of an earlier metal transport study employing K values from the Hazardous Waste Identification Rule (HWIR). The purpose of the current study is to assess whether the K values from HWIR can be used in the highly alkaline conditions expected from d CKD disposal. Earlier in this study, an assessment of the applicability of HWIR K values to the d CKD disposal scenario identified Ba, Be, Cd, Cr(III), and Pb as the metals most likely to have adsorptive behavior significantly different from the HWIR Subtitle D landfill scenario. The Kd values for the metals presented in this report are the result of modifying the HWIR modeling parameters to reflect groundwater conditions expected in land disposal of CKD. |