TY - JOUR
T1 - Elucidating the role of graphene oxide layers in enhancing N-Nitrosodimethylamine (NDMA) rejection and antibiofouling property of RO membrane simultaneously
AU - Khanzada, Noman Khalid
AU - Deka, Bhaskar Jyoti
AU - Kharraz, Jehad A.
AU - Wong, Pak Wai
AU - Jassby, David
AU - Rehman, Shazia
AU - Leu, Shao Yuan
AU - Kumar, Manish
AU - An, Alicia Kyoungjin
N1 - Funding Information:
The work described in this paper was fully supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. T21-604/19-R).
Funding Information:
Since IP is a fast and self-limiting reaction, governing the morphology of the PA layer or improving its rejection has proven to be a challenging task (as it occurs over an uneven microporous support layer, the thickness and free hole pore volume may not be consistent) [4,6]. Consequently, RO membranes endure low rejection against small, hydrophilic neutral contaminants (i.e., molecular weight ?150 Da), which are mostly toxic to human health [7]. Among these, N-nitrosodimethylamine (NDMA), a non-ionic, probable human carcinogenic disinfection by-product, is arguably the most difficult to remove. Thus, the removal of NDMA entails either ultraviolet (UV) photolytic process or UV-advanced oxidation process (AOP) downstream to the RO process, thereby raises the overall treatment costs [8].
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/3/1
Y1 - 2022/3/1
N2 - Water reclamation using reverse osmosis (RO) has become an indispensable component of the urban water supply system. However, the removal of low molecular weight contaminants of emerging concerns such as N-Nitrosodimethylamine (NDMA) from RO is challenging, thereby raising serious safety concerns about reclaimed water. Herein we modify RO membrane with graphene oxide (GO) using polydopamine (PDA) as crosslinking agent. The modification of commercial RO membrane via co-deposition of PDA-GO subsequently resulted in superior NDMA rejection (83 ± 3.57%) when compared with the membranes modified via GO, PDA, GO on PDA impregnated surface, and pristine RO. The narrow interlayer spacing of the GO (0.36 nm), attributed to its partial reduction occurred due to thin PDA layer formation on its both sides, exhibited enhanced sieving effect in addition to the coverage of free–volume hole-size of the polyamide layers which offered hindrance to NDMA permeation. In addition, CFU-enumeration and confocal laser scanning microscopy revealed that the partial reduction of GO did not significantly affect its associated antibacterial property when compared with the membrane modified via GO after PDA impregnation. However, enhanced antibiofouling performance was observed using optical coherence tomography (OCT) employed in this study for in-situ, real-time, and non-destructive fouling monitoring with better flux performance.
AB - Water reclamation using reverse osmosis (RO) has become an indispensable component of the urban water supply system. However, the removal of low molecular weight contaminants of emerging concerns such as N-Nitrosodimethylamine (NDMA) from RO is challenging, thereby raising serious safety concerns about reclaimed water. Herein we modify RO membrane with graphene oxide (GO) using polydopamine (PDA) as crosslinking agent. The modification of commercial RO membrane via co-deposition of PDA-GO subsequently resulted in superior NDMA rejection (83 ± 3.57%) when compared with the membranes modified via GO, PDA, GO on PDA impregnated surface, and pristine RO. The narrow interlayer spacing of the GO (0.36 nm), attributed to its partial reduction occurred due to thin PDA layer formation on its both sides, exhibited enhanced sieving effect in addition to the coverage of free–volume hole-size of the polyamide layers which offered hindrance to NDMA permeation. In addition, CFU-enumeration and confocal laser scanning microscopy revealed that the partial reduction of GO did not significantly affect its associated antibacterial property when compared with the membrane modified via GO after PDA impregnation. However, enhanced antibiofouling performance was observed using optical coherence tomography (OCT) employed in this study for in-situ, real-time, and non-destructive fouling monitoring with better flux performance.
KW - Graphene oxide
KW - NDMA Rejection
KW - Surface modification
KW - Water reuse
UR - http://www.scopus.com/inward/record.url?scp=85119051945&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2021.120043
DO - 10.1016/j.memsci.2021.120043
M3 - Journal article
AN - SCOPUS:85119051945
SN - 0376-7388
VL - 643
JO - Journal of Membrane Science
JF - Journal of Membrane Science
M1 - 120043
ER -