Investigation On Y_xSi_1-xO₂/Al₂O₃ Coupling Y_xSi_1-xO₂-SO₃H Self-assembled Membrane For Cleaning Oily Seawater

Due to the characteristics of large amount,high salt content and complex composition,oily seawater has become difficult to treat in depth.Conventional methods for treating oily seawater can not satisfy the requirements of water discharge and recycle standard.Due to its high efficiency,ultrafiltration membrane technology has been widely used in advanced treatment of oily seawater.However,there are many deficiencies of traditional ultrafiltration membranes such as high cost,complex preparation process,low permeation flux,poor selectivity and secondary pollution.These drawbacks seriously hamper the widespread application of traditional ultrafiltration membranes.Therefore,now looking for a type of membrane technology with low cost,high permeation flux and selectivity,simple preparation process becomes an important task to all researchers.In order to solve this problem,in this paper Y_xSi_1-xO₂/Al₂O₃ coupling Y_xSi_1-xO₂-SO₃H self-assembled membranes for cleaning oily seawater were studied.In this paper,Y_xSi_1-xO₂/Al₂O₃ functional particles were firstly prepared through co-hydrolysis,silanization and phosphorylation,followed by coating of Al₂O₃;Y_xSi_1-xO₂-SO₃H functional particles were prepared through co-hydrolysis,silanization and sulfonation.The optimum preparation conditions of functional particles were also determined.Moreover,functional particles were characterized and analyzed by SEM,TEM,FT-IR,XRD and UV-Vis.The results indicate that the particles prepared under the optimal conditions own spherical structure,Y elements have been successfully doped into the lattice of SiO₂ andγ-Al₂O₃ has been coated on the surface of Y_xSi_1-xO₂.Y_xSi_1-xO₂/Al₂O₃ and Y_xSi_1-xO₂-SO₃H particles and diatomite were employed as coating materials to form self-assembled membranes on porous supports.The optimum formation conditions of self-assembled membranes were determined,thereinto,the effects of operating pressure and flow state on the uniformity of self-assembled membranes were discussed.And the membranes formed under the optimal conditions were characterized by SEM.Furthermore,the membranes were used to treat oily seawater and the quality of permeate water was investigated and analyzed,thereinto,the effect of particle size of functional materials on the quality of permeate water was discussed.The results indicate that the membranes have asymmetric structure with a compact functional layer on the surface and a loose support layer inside with many channels,and the quality of permeate water could satisfy the requirements of water discharge and recycle standard.Moreover,the membranes have various advantages such as partial desalination and multistage operation.In addition,the effect of functional particles after calcination on regeneration of self-assembled membranes was studied and the functional particles before and after calcination were characterized by FT-IR.The results show that the structure of functional materials has not been changed after calcination,the optimum calcination temperature is 200°C,the regenerated self-assembled membranes still have the function of cleaning and desalination of oily seawater.Y_xSi_1-xO₂/Al₂O₃ coupling Y_xSi_1-xO₂-SO₃H self-assembled membrane with desirable separation and selective adsorption properties represents a promising substitution for traditional ultrafiltration membrane technology.