Abstract
Dissolved oxygen budget in a small oxidation pond for the gray water treatment is investigated by using a numerical model. The numerical model incorporates the relation between light intensity and the photosynthesis rate, extinction of incident light by photoplankton, sedimentation of photoplankton, vertical diffusion, atmospheric reaeration and benthic oxygen demand. Diurnal change of vertical distribution of dissolved oxygen concentration in a small pond is used for the verification of the presented model. By using parametric sensitivity analysis, the oxidation pond with the depth of about 1m seemed to be effective for the oxygen supply into the oxidation pond.
