SIMULATION-MODEL OF METHANOGENIC COMMUNITY

A universal basic model of anaerobic conversion of organic matter is suggested. Hydrolysis, acidogenesis, and methanogenesis are included in it. Dynamics of hydrogen partial pressure and its influence on acid-forming bacterial metabolism are taken into account. The model realized as user-friendly computer program allows to edit values of constants and parameters, to carry out numerical simulations, to plot the dynamics of variables in a quite convenient form, and thus to analyse the long-term dynamic behavior of an anaerobic system within a minute of computer time. According to experiments with food industry wastewater, its non-trivial dynamics is explained by the model simulations. Experimental data of Parkin et al. (1990) are used to describe the effect of sulphate reduction process on methanogenic activity. The model shows that under high critical influent sulphate concentration, high effluent hydrogen sulphide concentration inhibits methanogenic microorganisms. Subsequent acidification leads to complete degradation of anaerobic community. Similar calculations were implemented for acetate and propionate systems. The latter is shown to begin lo decline first.