Brine cleaning is an effective treatment for removing organic contaminants on strong and weak base anion resins in demineralizers, organic traps and Dealkalizer units. When working with elevated levels of organics in the feed water, it is smart to perform regular brine treatments as part of your planned preventative maintenance program.
The following cleaning procedure is quite effective:
- Run resin column to the exhaustion point at 25% of your normal service flow rate.
- Backwash at the regular DLFC (Backwash Flow Control) rate for 10-20 minutes. An air-sparging will be helpful – plan on a minimum of 4 Bed Volumes.
- Drain the bed completely.
- Pump 2 bed volumes (13 gal/cu.ft) of a warm 10% NaCl or 1% NaOH solution into the mineral tank.
- Drain to bed level over 1 hour and allow the regenerant solution to soak for a further 3-16 hours. (An alkaline brine solution warmed up to approximately 120°F (50°C) for type I and weak base anions or 105°F (40°C) for type II.
- Displace with 2-3 bed volumes water (15-20 gal/cu.ft) over 20-30 minutes.
- Rinse out with 3-5 bed volumes DI water fast rinse (20-40 gal/cu.ft).
- Regenerate the system twice (same regenerant concentration).
- Rinse and return the system to service.
- Run 80% of the standard run-cycle to drain.
- Regenerate the system.
Obviously, soft/softened water is the ideal for operation anion systems and ESPECIALLY for regeneration and remediation procedures like this.