39) Leighton, D.; Acrivos, A. Chem. Eng. Sci. 1986, 41, (40) Bhatty, J. I.; Reid, K. J.; Dollimore, D.; Shah, T. H.; Davies, L.; Gamlin, G. A.; Tamini, A. Sep. Sci. Technol. 1989,24, 157-185. (44) Adham, S. A.; Snoeyink, V. L.; Clark, M. M.; Bersillon, J.-L. J.-Am. Water Works Assoc. 1991,83, 81-91. (45) Wiesner, M. R.; Clark, M. M.; Mallevialle, J. J . Environ. Eng. 1989,115, 20-40. (46) Bhatty, J. I.; Reid, K. J.; Dollimore, D.; Shah, T. H.; Gamlen, G. A.; Tamini, A.Fluorescence quenching was used to measure the binding of pyrene and phenanthrene to marine interstitial water organic colloids from Boston Harbor, MA. Both pyrene and phenanthrene were sorbed by porewater colloids (Koc colloid -105.0 and 104.3, respectively) from a heavily contaminated nearshore site. Pyrene had a significantly lower affinity toward colloids from a cleaner location (Kmmuoid N 104.5). Sediments from the former site were also observed to be especially effective sorbents for these compounds relative to expectations based on the literature. The high sorption coefficients may be due to the high lipid content of these sediments and colloids. Alternatively, they may be due to a very substantial nonpolar character of the natural organic matter there.