Use of Innovative Techniques to Enhance the Hydraulic Disinfection Efficiency of Drinking Water Contact Tanks

Abstract

The focus of this study was to understand the complex nature of flow dynamics within water disinfection contact tanks and to use this understanding in the development of beneficial tank modifications. Methods involved in this process included the use of computational fluid dynamics (CFD) and physical conservative tracer studies. Attempted tank alterations included the installation of baffles, inlet modification, and the use of industrial packing material. Tested modifications aimed at altering existing velocity fields in order to increase the hydraulic disinfection efficiency of a given system. Hydraulic efficiency was measured through the use of residence time distribution (RTD) curves and the well-known baffling factor (BF). The principle system that was investigated was a 1500 gallon rectangular concrete tank. A total of 37 baffling scenarios were tested using CFD. After several CFD models were experimentally validated, random packing material was placed within the tank at areas of high velocity and flow separation. Results suggest that the innovative use of industrial packing material and other modifications can significantly increase the hydraulic efficiency of small scale systems and that CFD can be used as a guide in this endeavor.