SIMULATION-MODEL OF METHANOGENIC COMMUNIT Y

A universal basic model of anaerobic conversion of organic matter is s uggested. Hydrolysis, acidogenesis, and methanogenesis are included in it. Dynamics of hydrogen partial pressure and its influence on acid-f orming 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 dynami cs of variables in a quite convenient form, and thus to analyse the lo ng-term dynamic behavior of an anaerobic system within a minute of com puter time. According to experiments with food industry wastewater, it s non-trivial dynamics is explained by the model simulations. Experime ntal data of Parkin et al. (1990) are used to describe the effect of s ulphate reduction process on methanogenic activity. The model shows th at under high critical influent sulphate concentration, high effluent hydrogen sulphide concentration inhibits methanogenic microorganisms. Subsequent acidification leads to complete degradation of anaerobic co mmunity. Similar calculations were implemented for acetate and propion ate systems. The latter is shown to begin lo decline first.