engleski

Formulation of TiO2 photocatalyst for wastewater treatment by using fluid-bed granulation

In this paper, wet fluid-bed granulation is scrutinized as potential process technology for formulation of TiO2 photocatalyst. By its form TiO2 is nanostructured particulate system with high photocatalytic activity. Enlargement of TiO2 entities will allow much easier separation of photocatalytic substance from treated wastewater. Additional inlet process streams are filler and binder (top-spray mode), both prepared by using waste materials. Study of the process is focused towards detection of process and formulation properties that will synergically drive complex micro-scale events in a proper way and therewith result in a collective of stable, multi-component and water-insoluble enlarged entities, granules. A new formulation of TiO2 has to retain its high photocatalytic activity. In addition, our intention here is to detect the alteration of the property of gained group of entities, particle size distribution (PSD) with respect to granulation time. This will reveal dynamics of granulation of a multi-component particulate system. Process of physical transformation of TiO2 substance is modelled with mechanistic approach by using population balance. This implies testing the applicability of a 1-D discretized population balance with Size-Independent Kernel (SIK) coalescence model for simulating real dynamic development of a given property of a TiO2-filler collective, PSD. Used approach might indicate the presence and dominance of underlying mechanisms in the net granulation process. Optimization method that connotes minimizing the overall sum of squared errors is used for estimation of intrinsic process parameter, coalescence rate constant. Thus, kinetic of inherent physical conversion of TiO2 substance is quantified.

Wet fluid-bed granulation; TiO2; Particle size distribution; Process modelling; Population balance

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