Hydrophilic Selective
Nanochannels Created by Metal
Organic Frameworks in Nanofiltration Membranes Enhance Rejection of
Hydrophobic Endocrine-Disrupting Compounds
posted on 2019-11-14, 22:13authored byRuobin Dai, Hao Guo, Chuyang Y. Tang, Mei Chen, Jiayi Li, Zhiwei Wang
Rejection of endocrine-disrupting compounds (EDCs) by
thin-film
composite (TFC) polyamide membranes remains a challenging issue in
wastewater reclamation applications because of the unfavorable hydrophobic
interaction between EDCs and membranes. Herein, we investigated the
incorporation of hydrophilic metal organic frameworks (MOFs) into
the polyamide layer to create water/EDC selective nanochannels for
enhancing EDC rejection. Using MIL-101(Cr) MOF as a nanofiller, the
water flux of the MOF0.20 TFC membrane (0.20 wt/v % MOF in n-hexane) was 2.3 times that of the control. The rejection
rates against EDCs involving methylparaben, propylparaben, benzylparaben,
and bisphenol A (BPA) by MOF0.20 were also significantly higher than
the respective values of the control membrane, with the water/EDC
selectivity (e.g., A/BBPA) of MOF0.20 approximately doubled compared to that of the control.
Further single salt rejection and gold nanoparticle filtration tests
confirmed that the hydrophilic nanochannels created by MOFs played
a critical role in membrane transport, accounting for the significant
enhancement of EDC rejection of the modified TFC membrane. This study
demonstrates a promising membrane modification protocol using hydrophilic
MOFs for achieving selective removal of EDCs and high-efficient wastewater
reclamation using TFC membranes.