Treatment of Colorado River water with ozone, ferric chloride and Cat-Floc T-2

Abstract

Colorado River water (CRW) is a traditionally high quality source but it will require treatment for turbidity removal and disinfection in order to meet existing and future water treatment regulations. In this research, a treatment process consisting of preozonation followed by chemical coagulation, flocculation, and direct filtration was investigated. The effects of ozone, ferric chloride, and Cat-Floc T-2 doses on turbidity, UV absorbance at 254 nm, and total organic carbon (TOC) removal were statistically evaluated in order to determine the optimum chemical combinations required to achieve the treatment objectives. The ozone dose employed had the most significant impact (>99% confidence level) on turbidity removal. At a 99% confidence level, ozone and Cat-Floc T-2 were found to be statistically significant in reducing UV absorbance. There were no significant decreases in TOC observed with any of the treatment combinations studied. This was attributed to the low ozone doses employed. A second part of this research involved a study on the effects of the treatment chemicals on CRW after kaolinite had been added to artificially increase its turbidity.