Sorption of Chlorobiphenyls in Sediment—Water Systems Containing Nonionic Surfactants

Abstract

AbstractNonionic surfactants may aid remediation of contaminated soils and sediments by increasing aqueous concentrations of poorly water‐soluble organic contaminants. In order to explore the effects of nonionic surfactants on the sediment—water distribution of PCBs, a series of batch experiments was performed using four commercial nonionic surfactants (Triton X‐100, Triton X‐405, Triton X‐705, and Tween 80) and Red Cedar River sediment. Sediment—water distributions of 4,4′‐dichlorobiphenyl (Di‐CB), 2,2′,4,4′‐tetrachlorobiphenyl (Tetra‐CB), and 2,2′,4,4′,5,5′‐hexachlorobiphenyl (Hexa‐CB) were studied at aqueous surfactant concentrations ranging from zero to >1.5 times the critical micelle concentration (CMC) of each surfactant. The results show decreases in apparent soil—water distribution coefficients (K*) of PCB congeners at all surfactant concentrations as compared to the intrinsic sorption coefficient (K) in the absence of surfactant, unlike that previously reported. A new model incorporating a surface micellization concept for the sorbed surfactant phase was successfully applied to experimental data presented here and in a previous study.