Effects of Some Industrial Chemicals on Anaerobic Activity Measured by Sequential Automated Methanometry (SAM)

Abstract

An experimental study was conducted into the effects of exposure of anaerobic bacteria to some commercial industrial chemicals. Anaerobic activity was tested using Sequential Automated Methanometry (SAM). SAM measures small pressure increases caused by gas production in vials containing anaerobic bacteria. Tested were bleaching agents including hydrogen peroxide and sodium metabisulphite, mothproofing and insect repelling agents containing synthetic pyrethroids, a bacteriostatic agent and non-ionic detergents commonly used in the wool scouring industry. Actively digesting bacterial material was obtained from an experimental anaerobic system treating concentrated effluents from wool scouring industry. None of the tested chemicals, with the exception of the bleaching agents, displayed any serious adverse effects on anaerobic activity. One of the tested detergents and one of the tested bacteriostatic agents mildly stimulated gas productivity, while strong increases in gas productivity were observed with one of the pyrethroid-containing chemicals. Sodium metabisulphite inhibited gas production but inhibition was reversible. Hydrogen peroxide was highly toxic and completely inhibited methane production even at the lowest added concentrations.