Influence Of Hydrodynamic Condition On Characteristics Of Activated Sludge

The characteristics on the active sludge processing system under different aeration amount and rotate speed of continuous stirred tank reactor and different structure parameters of the corridor aeration tank were compared on a laboratory scale. Combined with the measure of PIV (Particle Image Velocimetry) and the technology of CFD (Computational Fluid Dynamic), the hydraulic conditions in active sludge processing system were analyzed, and the rules of influence of hydraulic conditions on the active sludge processing system were studied. As a result, the mechanism of the influence on the active sludge processing system posted by hydraulic conditions were revealed, the structure and function parameters of optimizing the active sludge processing system were put forward, the measures and suggestions on improving the hydraulic condition were given.The results show that within the range of the hydraulic condition chosen by the experiment, the biodegradation capacity and removing efficiency of COD and ammonia as well as the activity of microorganism increased first and then decreased with the increasing of shear function, and the amount of microorganism of active sludge and the Sludge Volume Index decreased first and then increased under the same condition. Within the conditions of proper water temperature, pH and concentration of nutrition, the biodegradation capacity and removing efficiency of COD and ammonia as well as the activity of microorganism increased first and then decreased with the increasing of the ratio of length and breadth together with the decreasing of the radio of breadth and depth, and the amount of microorganism of active sludge and the Sludge Volume Index decreased first and then increased under the same condition. The influence of hydraulic condition on the active sludge processing system is realized by the stirring of the micro living environment of the microorganism in active sludge which is used to grow in mass population. By adjusting the structure and function parameters of the active sludge processing system and optimizing the shear function and characteristics of diffusion, the hydraulic conditions can strengthen the characteristic and the function of the active sludge processing system as well as the working effect.