AWWA ACE58245

This study evaluated the potential of ozone-assisted biofiltration (OAB) for removing taste and odor(T&O) compounds. OAB is a two-step process. In the first step, ozone is added tobreakdown the natural organic matter (NOM) into bioassimilable organic carbon. In thesecond step, biologically active filters are used to oxidize the bioassimilable organiccarbon. Pilot testing of OAB was conducted at the Chandler Water Treatment Plant in Arizona aspart of an American Water Works Association Research Foundation (AWWARF) study.In these pilot studies, granular activated carbon (GAC)/sand and anthracite/sand mediawere evaluated parallely. To reduce removal by adsorption, exhausted GAC was used inthe GAC pilot filters. The results showed higher 2-methyl isoborneol (MIB) removals in filters with GAC/sandmedia compared to anthracite/sand. The MIB removals were a function of empty-bedcontact time (EBCT); higher MIB removals were observed in filters with higher EBCTs.Most of the MIB removal occurred in the top few inches of the filters indicatingpredominance of biological oxidation in the upper layers of the media. Increasing ozonedose resulted in slightly enhanced MIB removal. The GAC/sand filters outperformedanthracite/sand filters in terms of total organic carbon (TOC) and UV254 reductions. Higher heterotrophic plate counts (HPCs) wereobserved in GAC/sand filters compared to anthracite/sand filters indicating higherbioactivity in GAC/sand filters. Both GAC/sand and anthracite/sand filters producedwater with turbidities less than 0.2 NTU. Includes 5 references, figures.

Product Details

Edition:

Vol. - No.

Published:

06/15/2003

Number of Pages:

14

File Size:

1 file , 900 KB