Reductive dehalogenation of chloroanilines in anaerobic estuarine sediment

The reductive dehalogenation of chloroanilines (CAs) was investigated in anaerobic sediment/water systems. The sulfate content of the interstitial and overlaying waters was approximately 20 mmoles 1(-1) and the sediment was apparently sulfidogenic. The CAs exhibited first-order disappearance kinetics with the rate constants ranging from 0.012-0.005 day(-1) or half-lives between 40 and 672 days. Pentachloroaniline TPeCA), 2,3,4,5-tetrachloroaniline (2,3,4,5-TeCA) and 3,4,5-trichloroaniline (3,4,5-TCA) were transformed by the sequential removal of halogen from the para and ortho positions. The disappearance of the parent compound and accumulation of metabolites were simulated using a first-order branched kinetic model.