DESORPTION-KINETICS OF CHLOROBENZENES, POLYCYCLIC AROMATIC-HYDROCARBONS, AND POLYCHLORINATED-BIPHENYLS - SEDIMENT EXTRACTION WITH TENAX(R) AND EFFECTS OF CONTACT TIME AND SOLUTE HYDROPHOBICITY

A technique using Tenax TA (R) beads as ''sink'' for desorbed solute w as employed to measure the kinetics of desorption of chlorobenzenes, p olychlorinated biphenyls, and polycyclic aromatic hydrocarbons from la boratory-contaminated sediment. First-order rate constants of rapid an d slow desorption were in the order of 10(-1)/h and 10(-3)/h, respecti vely. The rate constants of slow desorption correlate well with the mo lecular volumes of the compounds used and decrease between 2 and 34 d of equilibration. Slowly desorbing fractions increase with both increa sing solute hydrophobicity and increasing equilibration time.