The influence of experimental conditions on the assessment of the toxicity of 2,4-dichlorophenol to the anaerobic bacteria of landfilled refuse

Abstract

The toxicity of 2,4-dichlorophenol (2,4-DCP) to anaerobic bacteria in refuse cultures was investigated at two temperatures (30° and 37°C) and after two different exposure periods to the toxicants. It was shown that at 0.52mM 2,4-DCP the time of exposure of microorganisms to 2,4-DCP affected the relative activity (Av) of the production of methane. Values of Av at the beginning of the steady-state phase were lower than those recorded two weeks later. The incubation temperature selected also critically affected the assessment of anaerobic toxicity; at 37°C an imbalance of the activities of fermentative bacteria and acetogens with those of methanogens was observed.