AWWA ACE99458

Atrazine and cyanazine are the most frequently detected s-triazine herbicides in the surface water supplies of Missouri. Higginsville, a rural community in north central Missouri, obtains its drinking water from an impoundment that collects agricultural runoff periodically containing elevated levels of s-triazines. Higginsville was the first water plant in Missouri to use granular activated carbon (GAC) filter-adsorbers for herbicide control and is a field study site for herbicide treatment by activated carbon. Batch adsorption experiments with pulverized Filtrasorb 300 GAC were conducted for atrazine and cyanazine in matrices containing different inorganic and natural organic compositions. Isotherm data were analyzed with the Freundlich isotherm model. The cometitive effect of natural organic matter (NOM) on herbicide adsorption was apparent for both raw and coagulated water. Freundlich K values were typically greater in organic-free water by factors of two to three over when NOM is present. The inorganic matrix had no discernible effect. Cyanazine was more weakly adsorbed than atrazine, but the competitive effect of NOM was similar for both compounds. Atrazine isotherms were strongly affected by the choice of initial concentrations.

Product Details

Published:

01/01/1999

ISBN(s):

1583210016

Number of Pages:

20

File Size:

1 file , 450 KB