PHYSICAL FACTORS NEGATIVELY AFFECTING EVALUATION OF LONG-TERM BIODEGRADATION EXPERIMENTS OF POLYCHLORINATED-BIPHENYLS

Behaviour of PCB added in the form of a technical mixture (Delor 106) and [C-14]PCB 77 into different aqueous model cultivation media in lon g-term experiments was studied, The work was focused on monitoring PCB recovery from liquid media in the absence of micro-organisms. GC-ECD and radioanalysis were utilised for determination of PCB in the examin ed systems, Strong relations between duration of experiments, composit ion of media, degree of chlorination of biphenyls, and recovery of PCB were found, The lowest yields of PCB were observed for the extracts f rom model solutions based on N-limited cultivation media without verat ryl alcohol and Tween 80, The addition of these components, mainly of Tween 80, caused a significant increase of PCB recoveries. Copyright ( C) 1996 Elsevier Science Ltd