Method of Continuous and Quasi-Continuous Forward Osmosis Desalination

Opportunity  

Forward osmosis (FO) is a rapidly developing technology, but its industrial applications in desalination remain limited due to the lack of suitable draw solutes. Hydrogels have emerged as promising agents, offering tuneable performance under external stimuli including heat, pressure and light. Their potential to advance FO desalination makes them a valuable focus for development. 

Technology  

The invention introduces an advanced draw solute for FO, enhancing water purification from feed solutions at low cost and low energy. The semi-IPN hydrogel used in this method minimises energy costs during the separation and recovery of purified water. Featuring almost zero reverse diffusion, the draw solute self-regenerates during the deswelling or de-watering process in the heating cycle. The semi-IPN hydrogels exhibit thermally responsive swelling and dewatering behaviour, efficiently releasing absorbed water at suitable temperatures, optimising the FO process.  

Applications & Advantages  

Application areas include the purification of various water sources, including seawater, brine and industrial wastewater. The invention is also useful in industries such as pharmaceuticals, food processing and manufacturing. 

Advantages: 

• Utilises temperature-responsive polymers to switch between hydrophilic and hydrophobic states, reducing energy consumption 
• Adaptable to different feed solutions and environmental conditions, enhancing its applicability across various industries
• Offers enhanced water purification capabilities