SORPTION AND DESORPTION CHARACTERISTICS OF CHLORDANE ONTO SEDIMENTS

The sorption and desorption of chlordane onto size-fractionated sedime nt and the effect of sediment organic matter on the sorption and desor ption characteristics of chlordane have been investigated. The correla tion coefficients describing the sorption as a linear function of sedi ment organic carbon content are high, indicating that the organic matt er content plays an important factor in the sorption of chlordane to s ediments. A comparison of log Kp for the well-defined sediment types i ndicates that the sorption of trans- and cis-chlordane, though signifi cant, is mostly independent of sediment particle size. The slope of th e curves describing the sorption on different particle size sediments were statistically significant indicating that a subtle adsorption dif ference among particle sizes exists. As in the case of sorption onto w ell-defined sediments, the slope of the curves were statistically diff erent from zero, indicating that particle size differences have some e ffect on the desorption of chlordane. A positive correlation of Kp's a nd Kd's for each sediment exists. The differences among corresponding Kp's and Kd's are less than the experimental error in most cases, indi cating no significant differences between the two parameters.