Highly thin film nanocomposite membrane based metal organic complexes for brackish water desalination

Abstract

Recently metal organic frameworks MOFs incorporated thin film composite membranes had great attention in separation processes due enhancement porosity with excellent selectivity.In this work, binary and ternary complexes as a green metal organic framework were successfully prepared using carboxymethyl cellulose as a cluster organic linker. The two types of MOFs were embedded with different loading amount in the selective layer through interfacial polymerization. The prepared meso-fillers MOFs were characterized by SEM, FTIR and EDX. Also the membranes were characterized by SEM and separation assessments. The Results showed that the optimum loading MOFs was 0.1 wt%. Both binary complex MOF1 and ternary complex MOF2 were enhanced the performance of the membrane and the impact was depended on the MOFs loading amount. At the optimum MOFs loading amount 0.1 wt.%, the permeate flux increased from 30 LMH to 36 and 41 LMH, for the neat membrane, MOF1 and MOF2 membranes respectively. As well NaCl rejection was significantly affected and improved by embedding these MOFs, where NaCl rejection increased from 69% to 93% and 97% for neat membrane, MOF1 and MOF2 membranes respectively to 7000 ppm of NaCl at 5 bar feed pressure. The prepared membranes based MOF1 and MOF2 with 0.1 wt.% were tested for 60 days to confirm the stability of polyamide layer and their performance properties. The cubic like structure for the polyamide layer was observed by SEM images for 0.1% ternary complexes filled membrane so this study demonstrates that the MOFs based membrane is a promising technology on the laboratory mode for water desalination.