AWWA WQTC62489

The control of disinfection byproducts in drinking water has become increasinglyimportant in recent years, especially the group that includes the trihalomethanes. Most ofthe control efforts have been directed toward preventing their formation, but this projectfocused on removing them after they are formed. Because trihalomethanes are extremelyvolatile, it was believed that air stripping would be a feasible method for reducing theirconcentration in treated drinking water. Therefore, this study investigated the cost-effectivenessof using an induced draft stripping tower to remove some of thetrihalomethanes from the treated water.The results showed that air stripping using an induced draft packed column is indeed ahighly effective method for removing THMs from water. At air-to-water ratios of 60 orgreater, the percent removal of total trihalomethanes generally exceeded 90%.Furthermore, the stripping operation had no discernable effect on the residual chlorineconcentration in the treated water.Chloroform was the easiest THM to remove while bromoform was the most difficult.Percentage removals ranged from 69% to 96% for chloroform and 32% to 87% forbromoform.The air-stripping operation appears to be very cost-effective, with the operating costcalculated to range from 0.37 to 1.1 cents per thousand gallons of treated water for thebest-case and worst-case scenarios, respectively. When the amortized capital costs areadded in, the total costs range from 0.92 cents per thousand gallons to 4.6 cents perthousand gallons for the best and worst-case scenarios, respectively. A realistic total costestimate will lie somewhere between the two extremes values, but it is probably closer tothe 0.92 cents per thousand gallon best-case value than it is to the worst-case one. Includes 18 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2005

Number of Pages:

19

File Size:

1 file , 420 KB