Leaching behavior of PCBs and PCDDs/DFs from some waste materials

Although it is well known that some waste materials and their incinerator residues contain persistent organic pollutants (POPs) such as PCBs and PCDDs/DFs, little attention has been paid to the leaching behavior of these chemicals because of their low solubility. Due to the coexistence of surfactants in wastes, however, leaching concentration of POPs may increase. Therefore, leaching tests with and without those substances were conducted in order to understand the influence of surfactant-like substances on POPs leaching. In those tests, linear alkylbenzene sulfonate (LAS) and humic acid were used as surfactant-like substances. Shredder residues from car/electrical goods recycling and fly ash from a municipal solid waste (MSW) incinerator were used in these leaching tests. Furthermore, an experiment was carried out to understand the influence of fine particles on the leaching concentration of POPs. The results indicate that surfactant-like substances increase the leaching concentration of POPs, and fine particles related closely to the transporting behavior of POPs.