Wind-Aided Intensified eVaporation (WAIV) and Membrane Crystallizer (MCr) integrated brackish water desalination process: Advantages and drawbacks

Abstract

Due to the increasing of water shortage problems, the need for inland brackish water RO will continue to increase in future. However, the primary limitations to further application of RO inland are the cost and technical feasibility of concentrate disposal. In this work, Membrane Crystallizer (MCr) and Wind-Aided Intensified eVaporation (WAIV) technologies have been applied in order to mitigate the impact of concentrates on the environment. In particular, the research activity has been carried out on a desalination system in which brackish water was first pre-treated, then desalinated through reverse osmosis (RO) operation. Finally, RO concentrates were further treated in WAIV and MCr units. The effect of the presence of organic contaminants and antiscalants were studied by analysing RO operations working at different recovery factors and with different pre-treatments. In the absence of an antiscalant, RO operates at 75% recovery factor and at a pH low enough to ensure no calcium carbonate precipitation. In the presence of an antiscalant, RO process might work until a recovery factor of 88%. The analysed integrated RO + WAIV + MCr system allowed to reach recovery factors as high as 76.6–88.9% and limit brine discharge to less than 0.75–0.27% of the raw water fed to the system.