Fluid disinfection with ultraviolet radiation and a chemical disinfectant

An on-line device for controlling a fluid treatment process configured to inactivate a microorganism in a flow of fluid using ultraviolet radiation and a chemical disinfectant, the device comprising:

• a memory for receiving a calculated database of dose response for the ultraviolet radiation and for the chemical disinfectant for a fluid treatment parameter, wherein the memory stores code, the code executable by a processor to:
• obtain input data about the fluid treatment parameter from the process;
• compare the input data with the calculated database;
• receive a treatment constraint, wherein the treatment constraint is based on a multi-target disinfection to determine an optimal sequence for the chemical disinfectant, wherein the multi-target disinfection comprises a plurality of disinfectants, wherein the treatment constraint is based at least upon a disinfection kinetic of each disinfectant;
• and
• adjust one or more of an amount of ultraviolet radiation and the chemical disinfectant added to the flow fluid in response to a difference between the input data, the calculated database, and the treatment constraint.