Anaerobic dechlorination of chlorinated pyridines in anoxic freshwater sediment slurries

Abstract

Abstract Transformation of several isomers of dichloropyridine (DCPR) under methanogenic conditions was studied in freshwater sediment slurries. 2,3‐ and 3, 5‐DCPR (10 mg/1) were completely removed by day 50 while 2,5‐ and 2, 6‐DCPR were not metabolized in the sediment slurries during 6 months incubation. 3‐Chloropyridine (3‐CPR) was detected as the intermediate product of 3,5‐DCPR amended sediment slurries while 2‐and 3‐CPR were detected in 2, 3‐DCPR amended sediment slurries. However, 2‐ and 3‐CPR were persistent in the sediment slurries and were not further metabolized. 2‐and 3‐CPR were also persistent in the sediment slurries amended with these compounds. 2, 3‐ and 3, 5‐DCPR were transformed at similar rates when both compounds were added simultaneously to the 2,3‐DCPR adapted sediment slurries. However, 3, 5‐DCPR was transformed faster than 2, 3‐DCPR when both compounds were added simultaneously into the 3, 5‐DCPR adapted sediment slurries. 2,5‐ and 2, 6‐DCPR were not transformed in the 2,3‐ or 3, 5‐...