EVAPORATION KINETICS OF POLYCHLORINATED-BIPHENYLS DURING BIODEGRADATION EXPERIMENTS

During microbial degradation of polychlorinated biphenyls (PCB) in liq uid media two processes take place simultaneously. elimination of PCB and evaporation of PCB. The physical loss of PCB due to evaporation ca uses frequently false positive results in long-term biodegradation exp eriments. Therefore, if only the PCB concentration is to be measured, its determination in both liquid and gaseous phase is essential for a correct appraisal of biodegradation. The kinetics of PCB evaporation h ave been monitored and the evaporation rate constants for individual P CB congeners have been determined. The values of evaporation rate cons tants show a good corelation with the values of the 1-octanol/water pa rtition coefficient.