Estimation of distribution coefficient of lead in geological matrices around uranium mining site

The fate of contaminant transport is mainly governed by the parameter called distribution (partition) coefficient, Kd. It is a measure of sorption of contaminants to soil. In the present study the sorption of lead in soil was carried out using laboratory batch method in different soil samples collected from different places around uranium mining site. The kinetics of lead sorption was also carried out at different time intervals which clearly indicates that sorption equilibrium for lead achieved at around 28 hours. To carry out the batch experiments for sorption study stable lead was used. The distribution coefficient of lead was estimated for top and one meter depth soil samples around Turamdih Uranium Tailings Pond. The Kd values vary from 6645 to 30941 l/kg and 6452 to 30138 l/kg respectively for top and one meter depth soil samples. Good correlation is observed with the distribution coefficient of lead and soil pH for both top and one meter depth soil samples. It is found that with increasing pH, Kd for Pb increases linearly. (author)