Ninety-five%+ water recovery from Yuma-MODE-RO-Feed (514 ppm total hardness as CaCO3 (THAC)) resulting in 10,028 ppm+ THAC will cause extensive precipitation. Our USBR-funded membrane-distillation-based seawater-desalination-pilot-plant-studies using surface-modified porous hollow-fiber-membranes (HFMs) exposed to hot-brine-crossflow showed: water-flux unaffected by upto18,000 ppm-level scaling-salt precipitates; salt concentration up to 19% (supported by ONR-funded-studies).
We propose a compact plastic cylindrical surface-modified HFM device in crossflow immune-to-fouling with a second solid HFM (SSHFM) as a water-vapor condenser to locally heat brine. Vacuum membrane distillation-generated water vapor undergoes vapor recompression followed by condensation in SSHFM bore. Plastic hydrocyclones separate scaling-salt crystals/precipitates externally from concentrated brine.