Electrodialysis Reversal Provides Effective Treatment Approach for Concentrating Reverse Osmosis Brine

Testing of an electrodialysis reversal (EDR) pilot unit for reverse osmosis (RO) brine minimization was performed. A mobile EDR piloting skid was leased from General Electric Company (GE) Water & Process Technologies for testing. The pilot unit was operated for 1,600 hours and analyzed for hydraulic and electrical performance. The RO brine, which is also the EDR feed, total dissolved solids (TDS) concentration averaged 3,040 mg/L during testing. The EDR unit achieved a maximum recovery of 80% and rejected 85% of the influent TDS when treating RO brine. The EDR unit increased the overall recovery of the desalting process to 92%. Throughout the pilot study, the EDR feed pressure and electrical resistance were steady during testing indicating stable operation. The high recovery and stable performance indicates that EDR is an effective treatment approach for concentrating RO brine.