1. Process engineering concepts

1.1 Heterogeneous environment

The fact that soil and groundwater are highly heterogeneous means that the applications advocated by conventional process engineering cannot be used, even with heterogeneous approaches such as "heterogeneous reactors with heterogeneous catalysts", for the simple reason that, in biological soil treatment, heterogeneity is not or only very slightly characterized. Predicting the success of the technology therefore depends on the natural heterogeneity of the soil and subsoil, and on the "artificial" heterogeneity of the pollutant concentration (which is not unrelated to the natural heterogeneity of the soil). It is impossible to make a statistical description of pollutant heterogeneity by carrying out a large number of measurements spread over the entire polluted...