As fresh water supplies become more limited, industry and municipalities are demanding greater treatment efficiency and resorting to alternative water resources that are often too difficult for traditional water purification methods to treat effectively. Reverse Osmosis (RO) is the standard for water purification and reuse, but it’s a 40 year old technology subject to inefficiency and failure. The industry standard of 75% recovery means 25% waste. Adding stages to increase recovery increases system and operational complexity, greatly reduces flexibility and increases risk of failure due to membrane fouling or scaling. The Closed Circuit RO (CCRO) process uses standard RO components in a new process design that has solved many of the limitations of traditional RO, reducing water waste by up to 80% and making operation easier and more reliable. CCRO works by recirculating pressurized feedwater until a desired recovery level is reached. Brine is replaced with fresh feed without stopping the process. Any desired recovery percentage can be achieved in a single stage, limited only by the scaling characteristics of the feed water. Frequent feed flushing and salinity cycling disrupt and greatly reduce scaling and fouling. This combination of performance characteristics makes CCRO systems reliable, flexible and affordable, even when treating challenging water sources such as municipal and industrial wastewater. The author presents process information, field data and case studies that illustrate how this new technology can apply to water and wastewater operators.
This presentation is available to AMTA Members only.
- Richard L. Stover, Ph.D.
- Independent Consultant
- AMTA Technology Transfer Workshop, Columbus, OH
- AMTA Technology Transfer Workshop
- Reverse Osmosis, Closed Circuit, Water Purification