Transformation of aniline and 4-chloroaniline in sediments from an industrial site

Biotransformation of the toxic industrial pollutants aniline and 4-chloroaniline (para-chloroaniline, PCA) was investigated in sediments from DuPont Chambers Works, NJ. Sediments were obtained from contaminated and background (lightly contaminated) locations of an aquifer and freshwater canal. Aniline loss was observed under aerobic, Fe(III)-reducing, nitrate-reducing, sulfate-reducing and methanogenic conditions in microcosms of background aquifer sediments. Aniline loss was also observed under Fe(III)-reducing, nitrate-reducing, sulfate-reducing and methanogenic conditions in microcosms of background canal sediments. We observed PCA loss under nitrate-reducing conditions in microcosms from background aquifer and canal locations and in the contaminated canal location. Nitrate loss observed in background aquifer material was near that stoichiometrically expected for nitrate-coupled aniline or PCA loss. In contaminated aquifer material, aniline loss occurred readily only under Fe(III)-reducing conditions and PCA loss was not observed under any redox condition. Results suggest that aniline and PCA contamination may be amenable to biological treatment under anoxic conditions.