Methanethiol production as an indicator of toxicity in anaerobic treatment

In the operation of a biological process, it would be helpful to have some indication of when the microcosm is under stress due to toxicity or otherwi se. Various indicators have been suggested. In this research it was found t hat the reduced sulfur compound methanethiol was produced when various inhi bitors were injected into a well operating system e.g. sodium ion, toluene, ethyl acrylate, tetrachloroethylene, octane, and chloroform. These inhibit ors were added at concentrations equivalent to 50% to 200% of their IC50 co ncentrations. Operation of the system with two primary substrates - acetate and glucose - were evaluated. Methanethiol production was found to be corr elated to inhibition.