Effects of Natural Organic Matter on PCB-Activated Carbon Sorption Kinetics: Implications for Sediment Capping Applications.

The article presents a study on the degree to which polychlorinated biphenyl (PCB) sorption to activated carbon are impaired by kinetic limitations, size exclusion effects and electrostatic repulsions. The study analyzes the sorption of 11 PCB congeners with activated carbon in fixed bed reactors with organic-free water (OFW) and Suwannee River natural organic matter (SR-NOM) through reconstituting freeze-dried SR-NOM at a concentration of 10 milligram (mg) L^-1 as carbon. Furthermore, the result of the SR-NOM fixed-bed test shows partial PCB breakthrough which occurred over the entire 320-d test. The study concludes that the formation of PCB-NOM complexes that reduce PCB sorption are likely to be the cause of the limitation in external mass transfer.