Modeling and control of water disinfection process in annular photoreactors

As an alternative or addition to complex physical modeling, in this paper transfer function models of the disinfection process in annular photoreactors under different flow conditions are derived. These transfer function models allow an analytical evaluation of the system dynamics and the control strategies to gain further insight while preserving the physical process parameters. For diffusive flow conditions a dead-time/Padé approximation is proposed to find a low-order linear system description. Given the (approximate) transfer functions with their physical process parameters, an analytical feed-forward - feedback law is further worked out.