Study On Hydraulic Simulation Of Rapid Formation Of Aerobic Granular Sludge

Compared with traditional activated sludge technology,the aerobic granular sludge(AGS)technology has advantages in many aspects: excellent setting characteristic, richer biological flora and so on. The formation of the aerobic granular sludge is under the influence of various factors: not only biological aspects such as organic load, inoculated sludge, but also hydraulic aspects. The paper has a research on the state of water flow in a continuous-flow reactor with pore plates and variation in different conditions.(1) In the beginning, the paper gives a description of the main purpose of pore plates in the preprocessing area from the perspective of theory. Firstly, the network board provide a growth environment for the microorganism. Secondly, the network board can improve the state of water flow in flow field. When the water flow after the pore plates, there will appear the Periodic production and fell of Vortex at the back of pore plates. Flow field inside the reactor is generally turbulent, the pore plates can provide the turbulent energy for the water, increased the number of vortex in flow field.(2) Measure the flow field inside the reactor by using PIV technology. there appears a big vortex in nearly infall area of reactor, the vortex-scale is as big as the reactor. As the flow capacity become bigger, the state of flow field inside reactor changes: the velocity magnitude generally become bigger, the rule of water flow keeps unchanged. Although the PIV technology is a high-quality, non-invasive and instantaneous measurement technique of full-field, the errors is inescapability. Due to the limitation of experimental equipment, the paper cannot measure all the flow field in this reactor. Instead, the other technology can help.(3) Introduced the formation and development and the usage of computational fluid dynamics in optimal design and operation of water treatment reactor. Use the fluent software to simulate the internal flow field characteristics of continuous flow reactor, and compare with the results of PIV measurement for validation, concludes that results of two methods achieved consistency, Fluent software can be an effective method to get a comprehensive characteristics of flow field in continuous-flow pore plates reactor through using Realizable k-? odel. The pore plats increase the number of vortex in flow field of reactor.(4) Research on the influence of different operation conditions, there will not appear the periodic production and fell of vortex at the back of pore plate when the mesh diameter is 1mm or 2mm under the flow capacity meet the request of organic load, the diameter of mesh is 4mm ma4 y as well. As the flow capacity become bigger, the velocity magnitude generally become bigger, the scope of function of pore plate become more widely, the frequency of fell of vortex become bigger; the decrease of distance between meshes also improve the scope of function of pore plate, the increase of number of mesh on pore plate improve the number of little vortex in flow field.The paper analyzed the characteristic of flow field in reactor in different operation conditions by using PIV technology and Fluent software, provide a reference for fast startup of AGS.