Computational fluid dynamics simulation of two-phase flow and dissolved oxygen in a wastewater treatment oxidation ditch

This study presents a computational fluid dynamics (CFD) model of an aerated wastewater treatment oxidation ditch, taking into account gas-liquid flow, oxygen mass transfer and dissolved oxygen. Especially, the effect bubble size distribution (BSD) biochemical demand (BOD) on (DO) has been considered. Species transport modelling predicts DO BOD distribution. De-oxygenation local by is modelled sink that depends concentration. Bubble coalescence breakup models predict BSD. The behaviour ditch non-ideal, which indicated residence time (RTD), heterogeneous flow pattern parameters with greatest influence are size. There good agreement between numerical simulation observations measurements mean DO. identifies BSD important for accurately predicting have mostly neglected in public research.