AWWA WQTC58892

The overall objective of this project was to identify and examine the key issues related to retrofitting existing granular media filters with membrane media filters in large water utilities. Specifically, the infrastructure, engineering, costs, training requirements, and compatibility issues associated with a large-scale membrane retrofit were addressed. The Kansas City Water Services Department (KCWSD) served as the six-month pilot-testing site. Settled water from the full-scale treatment plant served as the feed to the pilot units. The pilot study focused on the evaluation of two retrofit strategies: custom-designed, pressurized membrane systems; and, submerged membrane systems. These two strategies are particularly well suited to retrofit designs and therefore provided the economy-of-scale required for costeffective implementation. The custom-design approach was done with a pressure-vessel style, low-pressure membrane provided by two manufacturers. One of the modules being evaluated was a high-packing density, low-flux, low-transmembrane pressure module. The other is a high permeability module with a standard inside/outside hollow fiber design. Two implementation strategies were evaluated for the use of the pressurized vessel membranes at Kansas City Missouri Water Treatment Plant. The first approach was to utilize the existing head in the plant between final clarification and the clearwell in order to provide the operating pressure required for filtration. The second approach used feed pumps to provide the pressure required for a higher flux, lower capital alternative. The specific objective of the six-month pilot study was to establish a design flux and recovery, and to characterize and quantify membrane residuals for each membrane system tested. These design parameters are being used to facilitate the development of retrofit designs and cost estimates.