Black carbon(BC)in ten contaminated sediments from the Song-Liao watershed,NE China,was isolated upon treatments using a combustion method at 375℃,and the isolates’sorption isotherms for phenanthrene(Phen)were determined.All sorption isotherms were nonlinear and fitted well by the Freundlich model.A negative relation was found between Freundlich sorption nonlinearity parameter(n values)and BC/total organic carbon(TOC)content of the original sediments(r^(2)=0.687,p<0.01),indicating the dominance of BC in Phen sorption nonlinearity.The BC isolates from this industrialized region had n values of 0.342 to 0.505 and logKFOC values of 6.02 to 6.42(μg·kg^(–1)·OC^(–1))/(μg·L^(–1))n for Phen.At a given Ce,the BC had higher Koc value than the original sediments,revealing a higher sorption capacity for BC.BC was responsible for 50.0%to 87.3%of the total sorption at Ce=0.05 Sw,clearly indicating the dominance of BC particles in overall sorption of Phen by sediments.