In an effort to reduce brine (i.e., chloride) use and discharge for softening and barium
removal, the city of Crystal Lake, Illinois evaluated the use of calcium-form strong acid
cation exchange for the removal of barium. Bench-scale pilot testing was conducted to
evaluate the use of calcium chloride in lieu of sodium chloride for regenerating strong
acid cation resin. The calcium-form resin was used to selectively remove the barium
without affecting total hardness of the water. The selective removal of barium provides
longer run cycles between regenerations and thus a considerable decrease in chloride use
and 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 a
flowrate of 11 bed-volumes (BV) per hour. The ion exchange column was operated until
barium breakthrough was reached at 1.0 mg/L. The ion exchange system was operated at
different cycles using different calcium chloride regeneration concentrations and empty
bed contact times (EBCT). The use of hydrochloric acid (HCl) to restore the capacity of
the resin was also evaluated in this study. The results show that the use of calcium cation
exchange can successfully remove barium while significantly reducing chloride use and
discharge. The same technology can be used to remove radium or strontium from the
water. Includes reference, table, figures.
| Edition : | Vol. - No. |
| Number of Pages : | 7 |
| Published : | 06/01/2007 |
