Rapid processing of dispersed hydrate-based purification for high-yield seawater desalination and wastewater treatment

Abstract

Green utilization and sustainable desalination based on hydrate formation have attracted considerable attention. However, its industrial application is limited by slow kinetics and low final-conversion considering hydrate phase change. In this study, we creatively present a desalination approach of dispersed hydrate formation by incorporating the non-ionic surfactant Span 80. The addition of Span 80 enhanced the dispersion of cyclopentane (CP) in saline solution and generated the micron emulsion; as a result, the contact of the host water molecules and the guest molecules increased and the CP hydrate formation accelerated. Meanwhile, a maximum water yield of 92.8 % was achieved and the corresponding growth percentage of 97.5 % was realized comparing without Span 80 in a 3.5 wt% NaCl solution. In addition, this dispersed approach of hydrate-based desalination (HBD) also showed great performance in high concentration wastewater treatments like the solutions of saline and heavy metal. A three-stage purification strategy could produce the clean water meeting the stringent drinking water standard. Additionally, this approach exhibited notable pH tolerance under both strongly acidic and alkaline conditions. The results also demonstrated that Span 80 exhibits impressive self-separation recovery characteristics and cycling stability. These findings provide a robust academic foundation for advancing the feasibility and sustainability of the dispersed HBD in practical seawater desalination applications.