Modeling Persistent Organic Pollutants Adsorption at High Temperature: Batch and Continuous Studies

Abstract

In this study, we focused on the adsorption mechanism of Persistent Organic Pollutants (POPs) on two powdered materials—one activated carbon and one activated coke. The experiments were performed at laboratory-scale (150 and 180°C). The influence of temperature, humidity, and O₂ pressure was studied in batch reactors. Experiments showed, contrary to what was expected, that the disappearance of the compound was improved by increasing temperature. The degradation was not due only to an adsorption phenomenon but adsorption followed by a catalytic reaction on the surface of the materials. Moreover, experiments carried out under nitrogen pointed out that the presence of oxygen was necessary to catalyze the reaction. Due to the fact that an apparent equilibrium was obtained, adsorption models were applied on our experimental results and allowed us to obtain data on the retention capacity of the powdered materials, which will be necessary to design an industrial reactor. To simulate continuous flow conditions a laboratory-scale pilot (fluidized bed) reactor was built. Dynamic experiments were performed under identical conditions of temperature as the static ones. The adsorption–reaction capacity appears to be less important in dynamic than in static experiments. This seems to be in agreement with other literature results.