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AWWA ACE59888
- Coatings and Cement-based Biocides to Control Algae Growth and Taste & Odor Release in Water Distribution Canals
- Conference Proceeding by American Water Works Association, 06/17/2004
- Publisher: AWWA
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Characteristic earthy, musty, moldy, and fishy taste and odors (T&O) in drinking watersupplies have been attributed to algal sources. Periphytic algal growth on the surface of drinkingwater conveyance structures (e.g., open channel canals) may induce seasonal T&O episodes.Over the past four years growth of periphytic algae on the walls of a concrete-lined canalconveying surface water has preceded the release of T&O compounds (MIB and Geosmin atrates of 2 to 15 ng/L/mile) into the flowing water during the summer months. Copper applications and/or mechanical brushing techniques have been successful in reducing periphyticbiomass and preventing T&O production in the aforementioned canal. However, the use offixed-surface biocides to prevent periphytic algal growth before algae start producing T&Ocompounds may be more desirable. The main objective of this study was to determine theeffectiveness of three anti-fouling coatings and nine concrete mix formulations to inhibit theperiphytic algal growth on concrete structures. The anti-fouling coating EP2000 was a betterinhibitor of periphytic algae than the protective barrier coating Sun Wave. EP2000 and SunWave reduced periphytic algal growth by 99% and 35% for up to 3 months when compared tocontrol substrates. Algal growth inhibition was found to be directly proportional to the concretesamples zinc concentration. On-going research will be focused on the performance of EP2000and Sun Wave for longer periods of time in two source waters. A more comprehensiveexperimental matrix involving 40 mixture designs is currently in progress. Includes 9 references, tables, figures.