AWWA JAW17365

The research described in this article was conducted to quantify the reduction in the fouling potential of humic acid solutions following ozonation in the presence and absence of ultrasound and to examine total organic carbon (TOC) removal from humic acid solutions by ozonation in the presence and absence of ultrasound. Ozonation was most effective for reducing the fouling potential of low concentrations of humic acid solutions. The application of ultrasound during ozonation was detrimental to reductions in fouling potential of humic acid, possibly because sound waves reduced the average particle size of colloidal and suspended solids present in the solutions. The presence of colloidal silica in the humic acid solutions further reduced the fouling potential through the formation of a porous prefilter on the surface of the stimulant reverse osmosis membrane. It is believed that ultrasound destroys the prefilter effect by reducing the size of the colloidal particles and reducing the porosity of the cake. The kinetics of the destruction of humic acid TOC by ozone were shown to be firstorder. TOC removal rates were rapid during the initial 1-4 min reaction period, followed by slow oxidation with continued addition of ozone. TOC reduction was greatest when ozonation took place in the absence of ultrasound and at an initial pH of 5.5. Includes 18 references, tables, figures.

Product Details

Edition:

Vol. 77 - No. 8

Published:

08/01/1985

Number of Pages:

6

File Size:

1 file , 1.3 MB