BENEFITS OF AN INTEGRATED APPROACH TO WATER RECLAMATION FACILITY DESIGN AND OPERATION

Water reclamation facility design has traditionally been based on an “add-on” approach, wherein the facility is viewed as a combination of two distinct plants - a secondary treatment plant at the front end and an advanced treatment plant at the back end. The secondary treatment plant is typically designed and operated as a wastewater plant for removal of conventional pollutants, and all of the “reclamation” is assumed to occur at the back end in the advanced treatment (filtration / disinfection) processes. While the origin of this philosophy is understandable in that most reclamation facilities were expansions of existing secondary treatment facilities, the approach results in higher capital and operations costs because it fails to utilize the synergies that exist between the different treatment processes. A better approach is to view all processes as part of a single integrated system with the common end goal of producing high quality reclaimed water. Such an approach would make optimal use of all the synergies between the different processes, including the effect of secondary treatment sludge retention time (SRT) on filtration and disinfection performance, and the linkages between the filtration and disinfection processes. This paper presents the details of such an integrated approach and discusses the several associated benefits.