High-flux zwitterionic nanofiltration membrane constructed by in-situ introduction method for monovalent salt/antibiotics separation

Separation of monovalent salt and antibiotics is of vital importance in membrane field. In this work, zwitterionic polyamide membrane was prepared by incorporating N, N-diethylethylenediamine (DEEDA) into interfacial polymerization firstly. Then, zwitterions were introduced into membrane matrix via grafting reaction with 1, 3-propanesultone (1, 3-PS). The resulting zwitterionic membrane exhibited optimal permeability of 14.6 L m−2 h−1.bar−1 and high rejection of organics. Meanwhile, owing to the incorporation of zwitterions, the zwitterionic membrane showed lower rejection of monovalent salt compared with that of the pristine polyamide membrane. Thus, the zwitterionic membrane behaved efficient separation ability of monovalent salt/antibiotics when NaCl/erythromycin mixture solution was chosen as the experimental solution. When bovine serum albumin was used as a foulant, the zwitterionic membrane also exhibited anti-fouling property. This work provided a facile way to prepare zwitterionic membrane with efficient separation ability of monovalent salt/antibiotics, which promoted the development of zwitterions in applications of nanofiltration membrane field.