BEHAVIOR OF [C-14] 4-NITROPHENOL AND [C-14] 3,4-DICHLOROANILINE IN LAB SEDIMENT-WATER SYSTEMS .1. METABOLIC-FATE AND PARTITIONING OF RADIOACTIVITY

Using a standard screening procedure, the fate of [C-14]-4-nitrophenol and [C-14]-3,4-dichloroaniline was studied in lab sediment-water syst ems; incubation intervals ranged from 4 h to 90 d. The sediments were collected from a creek, a pond, and a drainage ditch of a fruit-growin g plantation, and were characterized. Both compounds and their transfo rmation products were sorbed to the sediments in large quantities; rad ioactivity left in the water phase was below 11% after termination of the experiments. Besides minor amounts of (CO2)-C-14, 3,4-dichloroanil ine was converted to predominantly nonextractable residues, presumably without preceding microbial transformation of the 3,4-dichloroaniline moiety. Two main end products were observed in the 4-nitrophenol expe riments, namely nonextractable residues and (CO2)-C-14. Data obtained from the sediment exhibiting highest microbial activity probably indic ated a further mineralization of 4-nitrophenol-derived sediment-bound residues. On the whole, 4-nitrophenol presumably shows low persistence and accumulation in sediment-water systems, whereas due to its stabil ity the toxicity of sediment-sorbed 3,4-dichloroaniline should be exam ined.