AWWA WQTC60781

Damon S. Williams Associates (DSWA) contracted with the City of Mesa, Arizona to evaluate theperformance of various adsorptive media at the Falcon Field 4 (FF#4) well site. The FF#4 well waschosen as a demonstration site based on its challenging water quality. Average water quality parametersare as follows: Arsenic = 32.3 µg/L (As[V] only), pH = 7.7, Silica = 35.5 mg/L, Sulfate = 47.0 mg/L,Phosphate = 0.014 mg/L as P, Vanadium = 13 µg/L.Ten media were initially tested using laboratory Rapid Small Scale Column Tests (RSSCTs) and batchtests. Three of the 10 media were selected for testing using a pilot-scale adsorption facility. The threemedia that were pilot tested are as follows: US Filter supplied GFH; Severn Trent supplied BayoxideE33; and, Solmetex supplied As:X^np.One of the project goals in the pilot column design was to track Arsenic breakthrough along the mediabed for full-scale design consideration. To accomplish this goal, sample ports were installed along thedepth of the media bed. By installing sample ports along the length of the column, the Arsenicconcentration profile could be tracked as it travels down the column. Each sample port along thecolumn represents a different EBCT and the Arsenic results from each port can be interpreted asindividual column tests. By normalizing the results against the bed volume above each sample port,information was gained about the importance of EBCT and competition on adsorption performance.In general, the variable EBCT testing showed mixed results. For two media, GFH and E33, it appearsthat shortening the EBCT has a small positive effect on adsorption performance for FF#4 water. It isspeculated that this performance gain is caused by less preloading of competing contaminants. Itappears that for the FF#4 water, Silica, Barium, and Vanadium had a detrimental impact on adsorption.It is theorized that this effect can be alleviated with shorter EBCTs, and further research is required tovalidate the theory. Includes table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/15/2004

Number of Pages:

7

File Size:

1 file , 1.3 MB