THE BINDING OF CONTAMINANTS TO HUMIN - A MASS-BALANCE

A mass balance is presented for the distribution of bound contaminant residues of 3 PAHs and 2 PCBs between the organic matter fractions of 3 different soil types. The PAHs and PCBs show rapid binding to soil w ith maximum binding happening within the first 30 days of contaminatio n. In all soils and contaminants studied humin contains more than 50% of the bound residue and typically between 70 and 80%. The humin is fu rther fractionated by the methyl isobutyl ketone partitioning method i nto three additional fractions: 1) lipid, 2) bound-humic acid, and 3) the insoluble residue. This further fractionation shows that the bound -lipidfraction has an extremely high affinity for the contaminants. Pu blished by Elsevier Science Ltd.