Modeling PVA degradation in a continuous photochemical reactor using experimental step testing and process identification

In advanced oxidation processes (AOPs) operating in continuous mode, the flow rate and concentration of oxidants such as H2O2 at mixing point influent must be controlled so that oxidant residuals effluent are minimized while organic degradation is maximized. Designing a controller to regulate therefore, its photoreactor influent, needs determination reliable process dynamic model. this study, step testing technique employed construct model for polyvinyl alcohol (PVA) UV/H2O2 annular photoreactor. The experimental design consists preparing three initial PVA concentrations 60, 280, 500 mg PVA/L conducting eight tests different inlet mass rates ranging from 0.336 125 H2O2/min. responses pH solution total carbon (TOC) measured versus time changes rates. Process models represented by transfer functions determined collected input-output data using graphical method, identification algorithm, ARX (AutoRegressive with eXogenous) Matlab environment. predict trend quite well. Variations steady state gain demonstrate nonlinear process. Besides, algorithm generates discrete could used develop digital controllers computer control photochemical reactor.