Prediction of metal removal efficiency from contaminated soils by physicalmethods

Six metal-contaminated soil samples were submitted to physical methods of t reatment. A wet magnetic separator, Wilfley shaking table, and jig gravimet ric separator were used on different soil fractions. A mineralogical model describing lead-bearing particles with and without iron oxide has been prop osed. A significant parr of the selected metals from each of the soil sampl es were removed by physical treatment. Linear regression analyses gave many relationships predicting the efficiency of the separation processes. The m ost useful variable to predict the magnetic process efficiency is the propo rtion of magnetic fraction removed. The density of fraction being removed w as the most significant factor predicting the performance of the Wilfley ta ble or the jig. The most significant variable predicting lead, copper; tin, and zinc removal was the initial metal concentration entering the process. Positive relationships between the results of the mineralogical study and the removal efficiency were found. These different relations confirm that t he proposed scheme and the associated quantitative mineralogical study (ide ntification of lead-bearing phase, carrying phase, and mean surface ratio o f lead-bearing phase on total surface of lead-bearing particles) proved to be useful.