Research Advances on Draw Solution in Forward Osmosis Process

Forward osmosis(FO),as a green membrane separation technology,is used in the process of desalting sea water and purifying polluted water due to the advantage of efficient recovery,low energy cost and less fouling membrane.Forward osmosis is a spontaneous migration process in which water molecular transports across a semi-permeable membrane from the domain with high osmosis pressure to that with low osmosis pressure,and during the process the driving power is offered by the osmosis pressure difference between draw solution and feed solution.Thus,draw solution is the major factor controlling the driving power in the process.The paper introduces the principle of forward osmosis,and reviews the advance on draw solution from the point of view at friendly environment.At last,the research direction of draw solution in forward osmosis technology is put forward.