University of Arkansas, Fayetteville


The US Navy is interested in improving the pretreatment for shipboard Reverse Osmosis potable water systems. To investigate this problem, the Navy prepared a Task for the 2010 WERC ( competition. The research described in this paper was performed to compete in this WERC Task and ultimately received a 1st place award. Several technologies were considered as options for improving the current pretreatment process. Multi-media filtration followed by ultrafiltration was chosen as the most economical solution. This paper presents the final design for a full-scale shipboard system that incorporates multimedia filtration and ultrafiltration yet requires minimal space and optimal power usage. Although the work focuses on oceanic applications, inland water desalination plants can economically use the technology. The proposed process provides an annual incremental savings, including reduced maintenance and filter usage, of $17,000 over the current process, resulting in a payback period of 14 years. However, as savings are highly dependent on the replacement frequency of all components, ships operating in coastal waters may realize greater savings of up to $47,000 annually, thus reducing the payback period to 5 years.