AWWA WQTC59028

The City of Wilmington's Brandywine Filtration Plant was originally built in the late 1800s.While upgrades have occurred over the years, the plant is in need of modernization to ensure asustainable and reliable water treatment and delivery system. A study was undertaken to evaluatethe existing treatment processes and condition of the plant infrastructure. Plant upgradealternatives were then developed and evaluated based on their ability to increase reliableproduction capacity, while fully complying with all current regulations and providing flexibilityto meet evolving future regulations. Results of the study indicated that an immersedultrafiltration (UF) membrane process would be the most desirable alternative. The immersed UFsystem was compared to and selected over plate/tube settlers, dissolved air flotation, and Actifloclarification because it could be located in the existing sedimentation basins in a historicaltreatment plant building and because of the enhanced pathogen removal offered by UFmembranes. The UF process had the highest present worth capital and O&M costs of all thealternatives evaluated. The driving force behind the process selection, more than cost, was thethe fact the process will not compromise pathogen removal if coagulation failure occurs, unlikethe other alternatives and conventional treatment. Based on these results the City implemented atwo-season pilot study to determine full-scale membrane operating conditions and design criteria.The pilot study was conducted for three months in the winter and two months in the summer toassess both cold water and warm water process performance of the membrane system.Membrane flux rates, chemical dosing of coagulant and acid, and recovery rates were varied todetermine optimum operating conditions during both seasons. The UF system met all treatedwater quality goals of the piloting program, providing significant improvement in all areas whencompared to the current plant. This report describes the piloting set-up and the results of theultrafiltration membrane pilot study. The collaborative efforts of the city, engineer, and vendormade the program a success. The project is currently in the preliminary design phase and willinclude an immersed UF process sized to treat 20 million gallons per day (mgd). The plant willbe the first municipal membrane plant in the state of Delaware and the largest operatingenhanced coagulation membrane plant in the United States. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

18

File Size:

1 file , 350 KB