Polybrominated Diphenyl Ethers Mobility in Biosolids-Amended Soils Using Leaching Column Tests

Leaching column tests were conducted to determine the mobility of polybrominated diphenyl ethers (PBDEs) in biosolids-amended soils. Deionized water was introduced from the bottom of a glass leaching column containing a 14-mm layer of biosolids-amended soils (210 g) under 42 mm of agricultural soil (600 g). After 4 weeks of leaching, 3.75 L of deionized water had passed through the 210-g biosolids?Csoil layer and 600 g soil, corresponding to 34 volumes of the leachate per volume of solid. The agricultural soil was divided into three 14-mm layers to determine the PBDE distribution along the flow path of the infiltrating water. PBDEs were found to leach from the biosolids-amended soils layer and migrate through the soil. The predominant congeners BDE47, 85, 99, 100, 153, 154, 183, and 209 decreased to 3?C98% of their initial concentrations in the biosolids-amended soil, whereas the total concentration of these eight congeners decreased by 38%. PBDE concentrations in the first 14-mm soil layer increased from not detected (nd) to up to 234?×?10³ pg/g dry weight basis (dw). Concentrations in the second and third soil layers increased from nd to 20 and 25 pg/g dw. PBDE in the leachate increased from nd to 310?×?10³ pg/L. Mobilization of PBDEs is likely associated with dissolved organic matter and colloids in the infiltrating water.