Three-dimensional three-phase model for simulation of hydrodynamics, oxygen mass transfer, carbon oxidation, nitrification and denitrification in an oxidation ditch.

摘要: Abstract A three-dimensional three-phase fluid model, supplemented by laboratory data, was developed to simulate the hydrodynamics, oxygen mass transfer, carbon oxidation, nitrification and denitrification processes in an oxidation ditch. The model provided detailed phase information on liquid flow field, gas hold-up distribution sludge sedimentation. described water-gas, water-sludge gas–sludge interactions. Activated taken be a pseudo-solid phase, comprising initially separated solid that transported later underwent biological reactions with surrounding liquidmedia. Floc parameters were modified improve viscosity, density, transfer rate, substrate uptake due adsorption onto activated sludge. validation test results very satisfactory agreement data behavior of By coupling species transport process models, reasonable predictions are made of: (1) biochemical kinetics dissolved oxygen, chemical demand (COD) nitrogen variation, (2) physical kinematics