A systematic approach for the design of UV reactors using computational fluid dynamics

A wide variation exists in the geometries of UV reactors, which results in completely different hydrodynamics and therefore large differences with respect to the disinfection and oxidation performance. Among the large number of reactor types, it is not known beforehand which reactor type has the best performance with respect to disinfection or oxidation, and if such a reactor is the best reactor out of all the possible reactor designs. In this research, a systematic approach for the design of UV reactors is followed that makes use of computational fluid dynamics (CFD) modeling. To that end, the inactivation of Bacillus subtilis and degradation of atrazine was determined for a wide range of UV systems by means of CFD. The efficacy of UV systems was evaluated and improvements were made by taking measures that increase the mean dose and/or narrow the dose distribution, such as placing mirrors, enhancing the mixing and placing reactors in series. © 2010 American Institute of Chemical Engineers AIChE J, 2011