AWWA ACE65185

In an effort to reduce brine (i.e., chloride) use and discharge for softening and bariumremoval, the city of Crystal Lake, Illinois evaluated the use of calcium-form strong acidcation exchange for the removal of barium. Bench-scale pilot testing was conducted toevaluate the use of calcium chloride in lieu of sodium chloride for regenerating strongacid cation resin. The calcium-form resin was used to selectively remove the bariumwithout affecting total hardness of the water. The selective removal of barium provideslonger run cycles between regenerations and thus a considerable decrease in chloride useand discharge. The bench-scale testing was performed using 1-inch diameter glass 40-inches long with 20-inches of bed depth. The downflow service mode was operated at aflowrate of 11 bed-volumes (BV) per hour. The ion exchange column was operated untilbarium breakthrough was reached at 1.0 mg/L. The ion exchange system was operated atdifferent cycles using different calcium chloride regeneration concentrations and emptybed contact times (EBCT). The use of hydrochloric acid (HCl) to restore the capacity ofthe resin was also evaluated in this study. The results show that the use of calcium cationexchange can successfully remove barium while significantly reducing chloride use anddischarge. The same technology can be used to remove radium or strontium from thewater. Includes reference, table, figures.

Product Details

Edition:

Vol. - No.

Published:

06/01/2007

Number of Pages:

7