Pervaporative desalination using MIL 140 A loaded polylactic acid nanocomposite membrane

Abstract

In this study, freestanding asymmetric MIL 140 A loaded polylactic acid (PLA)-based membranes were prepared and tested for pervapoative desalination. Membranes were characterized using different chemical and physical techniques. Desalination test was carried out with NaCl-water solution. The effects of MIL 140 A concentration (0, 1, 2, 3, 4 wt%), feed temperature (40, 50, 55, 60 ℃), NaCl concentration (2, 3, 4, 5, 6 wt%), and the downstream pressure (10, 15, 20, 25, 30 mbar) on the flux and the rejection were determined. As a result, MIL 140 A incorporation improved the hydrophilicity, durability, and the mechanical strength of PLA membrane. According to the results, a flux of 12.2 kg/m2.h with the rejection of 99.92 % was achieved by 3 wt % of MIL 140 A filled membrane at 60 ℃ with 10 mbar downstream pressure. A real sea water separation was also made with the 3 wt% of MIL 140 A loaded membrane and it was observed that the ion concentrations of the permeate were in drinking water standards. The prepared membrane was tested more than 160 h and no flux and salt rejection decrease was observed except for experimental errors.