SELF-PURIFICATION OF RIVERS A 2-PHASE MODEL FOR BACTERIAL BIODEGRADATION

A simple two-phase model has been developed, which accounts for up to 95% of the total oxygen consumption during the bacterial phase of river self-purification. The two phases are characterized by a logistic model. The first corresponds roughly to a destruction of 2 3 of the substrate, and is accompanied by the formation of cellular reserves. The second is the consumption of these stored substances, and begins when the external substrate ceases to be more attractive than the endogenous reserves. The cell yield as well as the stored material proportion appear to be constant, while the kinetic parameter ( μ ̌Ks-1) is strongly S0 dependent. All this can be studied through oxygen balances. © 1979.