Deep purification of seawater using a novel zeolite 3A incorporated polyether-block-amide composite membrane

In this study, a novel hydrophilic-hydrophobic composite membrane was prepared and used in a pervaporative desalination of NaCl-water solution and seawater. For this purpose, polyether block amide (PEBA) was selected as membrane matrix. Zeolite 3A was incorporated to PEBA polymer for facilitating the water permeation through the membrane. The surface morphologies of the pristine and composite membranes were examined by scanning electron microscopy. Thermogravimetric analyses of the pristine and composite membranes were performed by adjusting the zeolite 3A concentration in the PEBA polymer. The effect of the zeolite addition on membrane's surface hydrophilicity was analyzed using contact angle measurement. Firstly, influences of zeolite content, feed temperature and NaCl concentration on pervaporative desalination performances were performed in the pervaporation of NaCl-water solution. All membranes exhibited excellent performance, and the salt rejection of >99.5% and flux of >2.07 kg m−2 h−1 were achieved. Secondly, seawater desalination was performed. Effect of zeolite addition at a given temperature was also investigated. The better salt rejection was obtained as 99.81% accompanied with a very good flux of 4.57 kg m−2 h−1 in pervaporative seawater desalination at 40 °C using 20 wt.% zeolite 3A incorporated membrane.