A high-toughness anti-pollution polyethersulfone membrane for efficient separation of oil-in-water emulsions

Stable emulsion is the most difficult of all forms of oily wastewater to treat. Membrane separation technology has more advantages in solving related problems because of its high selectivity. The existence of hydroxyapatite containing more hydrophilic groups makes the membrane materials with high hydrophilicity obtained. In this work, hydroxyapatite was modified by strong adsorption of dopamine to prepare modified nanoparticles with good compatibility, which were more easily dispersed in the solution. Then the modified hydroxyapatite was introduced into the casting solution to avoid agglomeration and uneven distribution. The phase separation process was then completed by reverse thermal separation (RTIPS). After water flux and oil-water separation tests, high permeability (1515.46 L/m2 h, 14 times higher than the raw membranes) and high selectivity (99.80 % and 99.92 %) were obtained. At the same time, the membrane materials with the optimal conditions also achieved better performance in the cycle test. In addition, the bond between materials was improved due to the presence of hydroxyapatite, which ultimately makes the membrane materials more ductile and reduces the possibility of breakage.