Abstract
This study demonstrates a highly effective hydrate-based process for simultaneous water treatment and concentration cycling using real seawater samples, coupled with the synthesis and purification of high-purity MgSO4. Experiments were conducted in a novel closed-loop recirculation system with a 3.2 L laboratory-scale setup, with cyclopentane as the guest molecule for hydrate formation. The proposed process successfully recovered 40% of fresh water and 50% of concentrated brine per cycle, achieving ion enrichment factors of 4 to 5.5. This work is the first to use a laboratory-scale hydrate system for the efficient cyclic concentration of brine (>100,000 mg L−1 total dissolved solids) with ultrahigh salinity exceeding the operational limit of conventional reverse osmosis technologies. Furthermore, this study systematically investigates the purification of high-purity MgSO4·6H2O (>80% purity) from the CPH-derived concentrated brine using two organic solvents—ethanol and acetone—thereby opening promising application avenues. This research successfully establishes an integrated closed-loop process combining desalination, concentration, resource recovery, and solvent-based purification, offering transformative potential for sustainable resource recovery from high-salinity brine.
Graphical abstract
Tran, Q.N., Nguyen, D.A., Le, L.C., Nguyen-Gia, H.D., Le, T.H., Tran-Hoang, T.M., Nguyen, H.-Q. and Truong-Lam, H.S. (2026) Desalination, 120611.