Combined NF and RO Concentrate Disposal Piping and Deep Injection Well Scaling: A Case Study

The aeration of combined NF and RO concentrate has resulted in unprecedented scaling in both the downstream disposal piping and deep injection well at the City of Deerfield Beach West Water Treatment Plant. Investigation results indicated that iron (31 to 56%), phosphorus (18 to 23%), calcium (12 to 24%), and sulfur (2 to 11%) make up the main components of the scale deposits found in the concentrate disposal system. Further growth in potable water demands will drive the industry to increased membrane system recoveries. Systems with increased recovery have been operating successfully on groundwater in Florida; however, this case study from Deerfield Beach highlights significant scaling potential from a combined concentrate after aeration– a precautionary example, which will be shared with industry peers.