Comparative study for the preparation of superparamagnetic-citric coated magnetic nanoparticle and fo-desalination application

Forward osmosis as a unique low energy process, has achieved a greet attention, especially in desalination and water reuse applications. To make Forward osmosis more practical suitable draw solute with a good solubility, i.e. does not require energy, and non-toxicity properties have to be chosen or synthesised. In this study superhydrophilic, citric coated magnetic nanoparticles (Cc-MNP (1)) and Cc-MNP (2) were synthesised using a reverse co-precipitation and coprecipitation method, respectively. Both salts were demonstrated as an efficient draw solute in extracting water from saline water during-Forward osmosis experimental investigation. Forward osmosis performance-of both draw solutes was evaluated by using a commercial Forward osmosis membrane. The concentration effect of Cc-MNP (1) and Cc-MNP(2), feed salinity was investigated systematically. In Forward osmosis mode water flux of 28.6 L/m 2 hr with 300 g/L CcMNP(1) and 21 L/m 2 hr with 300 g/L Cc-MNP(2) were attained, also, it was found that water flux decreased with increasing feed salinity to become 5L/m 2 hr with 300 g/L Cc-MNP(1) in case of using 35,000 ppm NaCl feed. The osmotic pressure of the optimum draw solute (Cc-MNP (1)) at a concentration of 300 g/L was 51.2 bar as evaluated from the freezing point depression measurements.