Heavy metal mobility in, biosolids-amended glaciated soils

The mobility of heavy metals from one-time application of biosolids (i.e., compost, pellet, and cement kiln dust stabilized biosolids) onto glaciated soils (Paxton soil). was studied because previous work on metal leachate ch aracteristics, from different biosolids is limited for glaciated soils. Two types of batch tests were performed: first, a pH-edge adsorption study to evaluate the effect of pH on heavy metal adsorption to Paxton soil and, sec ond, a pH-edge leaching study to evaluate the effect of pH on the leaching potential of heavy metals from biosolids-amended Paxton soil. Finally, a se micontinuous soil column study was performed to assess. the mobility of hea vy metals from biosolids-amended Paxton soil. The pH-edge leaching results showed that the leaching potential of heavy metals was lower with the compo st product. Desorption concentrations for arsenic, chromium, and lead were found to be greatest in the cement kiln dust stabilized product whereas cad mium, copper, and nickel were present at the greatest concentrations in the pellets. The total organic carbon results measured during the pH-edge leac hing study indicated that there is a minimum leachable concentration in the pH range of 4 to 5 for all three biosolids. Overall, the column studies in dicated that heavy metals were not readily leached from the three biosolids -amended Paxton soils. The results from this study suggest that a one-time land application of these biosolids will not adversely affect groundwater q uality.