July 22, 2024, DR. Johan vanneste, colorado school of mines, golden, jefferson county, CO. ? This proposal implements the bureau of reclamation?s desalination and water purification research program…

The Department of the Interior Bureau of Reclamation awarded $449,640 to the Trustees of The Colorado School of Mines on December 1, 2025, under the SECURE Water Act – Research Agreements program (CFDA 15.560) to optimize optical scaling detection in conventional plug-flow reverse osmosis (RO) systems for desalination and water purification.

The recipient will adapt and optimize a scaling detection algorithm originally developed in a closed-circuit RO pilot system to conventional RO configurations, building on prior USBR agreement R22AC00431. The work includes laboratory testing with synthetic solutions on a 2 GPM, 4-element hybrid conventional RO/CCRO system, followed by field testing at two sites for at least 12 months total. Successful detection performance in conventional RO will establish the foundation for comprehensive techno-economic analysis. If the adapted algorithm achieves zero-scaling performance comparable to closed-circuit operation in the field, the project will demonstrate how scaling detection can minimize membrane cleaning requirements, extend membrane life, and enable higher water recovery rates. The research further explores scaling detection application to low-salt rejection RO configurations designed to achieve near-zero liquid discharge water recoveries at recovery factors not previously possible under conventional membrane pressure limitations.

Performance occurs in Colorado. The period of performance runs from December 1, 2025, through September 30, 2027. The award is structured as a cooperative agreement.

July 22, 2024, DR. Johan vanneste, colorado school of mines, golden, jefferson county, CO. ? This proposal implements the bureau of reclamation?s desalination and water purification research program (dwpr) priorities of improving conventional and novel high-recovery plug flow reverse osmosis (RO) technologies through scaling control and concentrate minimization. This proposal builds on a previous successful pilot-scale demonstration of an optical scaling detection system in a 20 GPM closed-circuit RO (ccro) system from dupont (usbr agreement # R22AC00431). ? The team aims now to adapt the scaling detection algorithm and optimize operating parameters of the much more widespread conventional plug flow RO systems to maximize scaling detection sensitivity. A 2 GPM 4? Element hybrid conventional RO/ccro system will be used to optimize scaling detection in conventional RO (CRO) and determine potential differences in detection efficiency and/or maximum recovery with ccro operation. Successful detection in CRO with synthetic solutions is the first milestone. The system will then be tested at two field sites for at least 12 months (total). The data of the extensive field-testing campaign is essential to perform a comprehensive techno-economic analysis. If the adapted scaling detection algorithm can achieve the same zero scaling performance as in ccro in the field, the second milestone will be achieved. This will minimize required pilot testing time, need for chemical cleaning, and ultimately replacement of membranes and increase average water recoveries, as RO can be operated close to the scaling limit. ? Moreover, the advent of low-salt rejection RO (lsrro) enables unprecedented, near zero liquid discharge (nzld) water recoveries, not limited anymore by membrane pressure limitations. While the configuration is much more complicated, a single RO stage in lsrro operates just like CRO. The high recovery factors of lssro will only materialize if a scaling detection system is implemented as well. The unique 4 and 40 GPM lssro systems at mines equipped with the optical detection system will therefore also benefit from the new optimized detection algorithm for CRO. Successful detection and scaling prevention in lsrro is the third milestone of the project. ? The project will last for 18 months of which at least 12 months will be at two field sites. If the project starts in october 2025, we hope to get in the field by march 2026 and finish field testing in march 2027. Due to the majority of the work being off campus, an indirect cost rate of only 26% is applicable. Lastly, a cost share of 37.4% will be provided. ? The primary field site is at the shaklee center metropolitan district in hudson, CO. The second and third field site are in FT. Collins, CO. Neither of these sites are on federal land.