KINETICS OF BACTERIAL-DEGRADATION OF BENZYLAMINE IN A MONTMORILLONITE SUSPENSION

A model was developed for the biodegradation by nongrowing microbial populations of sorbed organic chemicals that are readily desorbed. The model requires inputs in the form of parameters provided by separate measurements of the adsorption isotherm under aseptic conditions and the rate of biodegradation in the absence of sorbent. The only parameter that must be provided by the data to be simulated is the fraction of carbon from the test compound that is incorporated into microbial cells or retained by the sorbent. The model was tested with benzylamine as test compound, a bacterial isolate able to mineralize the chemical, and montmorillonite as sorbent. Benzylamine mineralization by high cell densities of the bacterium was slower in the presence of montmorillonite than in the absence of the clay. Experimental curves for bacterial mineralization of benzylamine in well-dispersed suspensions of montmorillonite were reproduced by the model with standard deviations of usually less than 4%.