Diffused air aeration Aquavarra（空气扩散曝气Aquavarra）.pdf

Aquavarra Research Publications Water Engineering Papers Paper 4 Title: DIFFUSED AIR AERATION SYSTEMS FOR THE ACTIVATED SLUDGE PROCESS DESIGN PERFORMANCE TESTING Author: Professor T J Casey Aquavarra Research Limited 22A Brookfield Avenue Blackrock County Dublin Ireland www.aquavarra.ie August 2009 Aquavarra Research RD Publication Paper 4, August 2009 DIFFUSED AIR AERATION SYSTEMS FOR THE ACTIVATED SLUDGE PROCESS DESIGN PERFORMANCE TESTING 1. INTRODUCTION Aeration systems normally perform two functions in activated sludge wastewater treatment processes, namely, oxygen transfer and mixing. While oxygen transfer may be regarded as the primary function, mixing is also important to ensure a full utilisation of the activated sludge reactor volume and a uniform dispersion of dissolved oxygen throughout the mixed liquor. However, in some applications of the activated sludge process, a mixing input is provided which is independent of the aeration system, thereby relieving the aeration system of its mixing function. Where an independent mixing system is provided, the specific mixing power input required is dependent on the reactor configuration, being typically in the range 3 to 6 W/m3. The specific pow