Effect of Chlorine Substitution on the Biodegradability of Polychlorinated Biphenyls

摘要: Thirty-one isomers of polychlorinated biphenyl (PCB) were examined for biodegradability by two species Alcaligenes and Acinetobacter. The following relationships between chlorine substitution PCBs observed. (i) Degradation decreased as increased. PCB containing more than four chlorines less susceptible to degradation. (ii) on either the ortho position a single ring (i.e., 2,6-) or both rings 2,2′-) showed very poor degradability. (iii) all atoms only generally degraded faster when same number substituted rings. (iv) Preferential fission molecules occurred with nonchlorinated lesser chlorinated (v) formation accumulation yellow intermediate was always observed in 4′-chloro-substituted PCBs. (vi) Significant differences organisms respect degradability not except 2,4,6-trichlorobiphenyl.