TY - JOUR
T1 - Electrically conductive membranes for contemporaneous dye rejection and degradation
AU - Anis, Shaheen F.
AU - Lalia, Boor S.
AU - Lesimple, Alain
AU - Hashaikeh, Raed
AU - Hilal, Nidal
N1 - Funding Information:
This work was supported by the NYUAD Water Research Center , funded by Tamkeen under the NYUAD Research Institute Award (project CG007).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/1/15
Y1 - 2022/1/15
N2 - Ultrafiltration (UF) and nanofiltration (NF) membranes have attracted great research interest to treat dye wastewaters. However, UF membranes suffer from low dye rejection and NF membranes have low salt recovery. There is a tradeoff between the dye rejection and salt recovery in the UF and NF membranes. A novel membrane is required for dye rejection with high salt recovery. Herein, we report a novel UF conductive ceramic membrane made from nano-zeolite and carbon nanostructures (CNS) combined with an external electric potential to treat crystal violet (CV) dye/NaCl-Na2SO4 salt solution. The membrane showed trimodal hierarchical porosity, a water contact angle of ≈40°, good flexibility and high electrical conductivity. Voltages from 2 to 15 V were applied to the membrane acting as a cathode in a cross-flow filtration setup. High dye rejections ≈100% with a flux of 210 LMH at a voltage as low as 3 V were achieved. Contemporaneous dye degradation was observed with several intermediate compounds, identified through mass spectroscopy. It was observed that higher potentials produced nitrates/nitrites from organic intermediates as deduced from ion chromatography results. Donnan steric repulsion increased with higher potentials, leading to increased ion transfer resistance for anions and improved permeation for cations. Various permeate properties such as pH and conductivity were monitored, along with high salt recoveries, hence providing a huge advantage of using such a membrane for treating dye wastewaters with selective dye/salt rejection. The versatile properties, together with its facile fabrication process indicates tremendous prospect of zeolite/CNS membranes for multipurpose applications treating wastewaters containing charged molecules and ions.
AB - Ultrafiltration (UF) and nanofiltration (NF) membranes have attracted great research interest to treat dye wastewaters. However, UF membranes suffer from low dye rejection and NF membranes have low salt recovery. There is a tradeoff between the dye rejection and salt recovery in the UF and NF membranes. A novel membrane is required for dye rejection with high salt recovery. Herein, we report a novel UF conductive ceramic membrane made from nano-zeolite and carbon nanostructures (CNS) combined with an external electric potential to treat crystal violet (CV) dye/NaCl-Na2SO4 salt solution. The membrane showed trimodal hierarchical porosity, a water contact angle of ≈40°, good flexibility and high electrical conductivity. Voltages from 2 to 15 V were applied to the membrane acting as a cathode in a cross-flow filtration setup. High dye rejections ≈100% with a flux of 210 LMH at a voltage as low as 3 V were achieved. Contemporaneous dye degradation was observed with several intermediate compounds, identified through mass spectroscopy. It was observed that higher potentials produced nitrates/nitrites from organic intermediates as deduced from ion chromatography results. Donnan steric repulsion increased with higher potentials, leading to increased ion transfer resistance for anions and improved permeation for cations. Various permeate properties such as pH and conductivity were monitored, along with high salt recoveries, hence providing a huge advantage of using such a membrane for treating dye wastewaters with selective dye/salt rejection. The versatile properties, together with its facile fabrication process indicates tremendous prospect of zeolite/CNS membranes for multipurpose applications treating wastewaters containing charged molecules and ions.
KW - Carbon nanostructures
KW - Conductive ceramic membranes
KW - Dye degradation
KW - Dye rejection
KW - Electrolysis
KW - Water analysis
UR - http://www.scopus.com/inward/record.url?scp=85109939951&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85109939951&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2021.131184
DO - 10.1016/j.cej.2021.131184
M3 - Article
AN - SCOPUS:85109939951
VL - 428
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
M1 - 131184
ER -