Abstract
In a suspension of Ohshiro soil activated for dechlorination, benthiocarb (thiobencarb, S-4-chlorobenzyl N, N-diethylthiocarbamate) was dechlorinated after a lag period by amending with sugars, starch, cellulose, and ascorbate but not with several amino acids. The dechlorination activity was greatly affected by the concentration of organic additives, temperature, and pH of the suspension, and these factors worked within very narrow ranges. The optimum condition was 25°C-30°C and pH7. The reaction rate in the suspension was greater under N2 than air. Even under aerobic conditions, the reaction did occur, although it started after a long lag period and proceeded slowly. Therefore, the dechlorinating microbes were suggested to be facultative anaerobes and the lag period for the dechlorination to be a time for proliferating dechlorinating microbes.
