PCB INTERACTIONS WITH SOIL

Studies were undertaken to examine the interaction between polychlorinated biphenyls (PCB‘s) and soil. Both field samples and laboratory prepared samples were examined. Samples of soil were taken from the 0.7 m depth at a transformer producing industry at which PCB spills had occurred. These were extracted to determine their PCB content. Concentrations ranged from 0.1 to 41.7ng PCB (as Aroclor 1254)/g soil. One of the more highly contaminated soils was subsequently desorbed with water to determine the extent to which the release of PCB to solution occurred. Concentrations in the desorption water ranged from 5 to 29 yg/l, and correspond to 0.11 to 0.55% desorption from the soil. Laboratory experimentation centered upon conducting a simulated PCB spill. Aroclor 1242 was poured onto a soil sample. This yielded an equilibrium pore occupancy of approximately 50%, or a sorption capacity of about 0.07 g/g soil. The stability of this sorption was then tested by desorbing with water. Initially concentrations in the desorption water exceeded the solubility limit of Aroclor 1242 in water. Subsequent concentrations reached 45 ug/1 after 45 pore volumes of desorption water had been applied. This corresponded to 99.97% retention on the soil. Parallel experiments demonstrated that the extraction process was capable of recovering over 70% of the spilled Aroclor. Copyright © 1979 by Marcel Dekker, Inc.