AWWA WQTC60658

This paper presents the results of an extended series of pilot testing designed to use existingand novel methods to control bromate formation at the Colored Water Treatment Facility (CWTF). Based on previous workperformed by other water utilities, information in the scientific literature, and some earlierpilot testing performed by McGuire Environmental Consultants, Inc. (MEC) on a similar rawwater quality, a pilot plant was designed and constructed at the CWTF. The goal of the pilottesting was to simultaneously produce treated water that would meet Mesa's color target of 7 to 8 color units (PCU) and the Stage 1 Disinfectant/Disinfection Byproduct (D/DBP) RuleMaximum Contaminant Level (MCL) of 10 mg/L.The pilot plant was used to test various combinations of allowable drinking water treatmentchemicals and their effect on bromate formation for the challenging raw water quality foundat the CWTF. When it became clear that the target water quality could not be reliablyachieved using chemical pretreatment alone, an additional treatment process (MIEX, orMagnetic Ion EXchange) was tested. MIEX treatment had been previously shown to behighly effective at color removal, and it was hypothesized that increased color removalwould result in lower ozone doses and reductions in bromate formation. Finally, when thisconfiguration was found to be insufficient for meeting both color and bromate targets, theorder of treatment was switched, and the MIEX treatment process was used as a polishingstep to remove color that was not previously removed by ozone treatment. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/15/2004

Number of Pages:

20

File Size:

1 file , 950 KB