Biological pretreatment: An innovative approach to addressing taste and odor

Abstract

The presence of objectionable taste-and-odor (T&O) compounds in surface water supplies is a common problem facing drinking water utilities across the country and worldwide. While there are several viable T&O treatment options, including adsorption, biotransformation, and advanced oxidation, no single option fits all applications or is without potential limitations. Through bench- and pilot-scale testing, this work developed and evaluated high-rate biological roughing filtration as a promising alternative for geosmin and 2-methylisoborneol abatement to help utilities minimize T&O complaints without straining their annual operating budgets. Testing showed that biological roughing filtration can effectively treat a wide range of raw water T&O levels using short contact times, and the intermittent presence of T&O compounds did not appear to appreciably affect removal efficacy. Pilot-testing results were used to develop the design criteria for a full-scale 54-mgd biological roughing filter that is currently treating surface water in Manatee County, Florida.