(376aa) A Novel Cationic Guanidine Compound Grafted Polyvinylidene Fluoride Membrane for Biofouling Mitigation

A
novel cationic guanidine compound grafted polyvinylidene fluoride membrane for
biofouling mitigation

Shanshan
Zhao ^{a, b}, Guimei Liu ^{a, b}, Fangang Meng ^{a, b, *}

^a School of
Environmental Science and Engineering, Sun Yat-sen University, Guangzhou
510275, PR China

^b Guangdong Provincial Key
Laboratory of Environmental Pollution Control and  Remediation Technology,
Sun Yat-sen University, Guangzhou 510275, PR China

Abstract

Membrane
separation technologies have gained wide application in water and wastewater
treatment. However, membrane fouling, particularly biofouling, remains a
critical issue in the real applications. The undesired bacterial adhesion and
subsequent biofilm formation on the membrane surface severely declines the
separation efficiency and increases operation cost. Membrane
surface modification is an emerging method to mitigate biofouling. In this
study, a novel antibiofouling polyvinylidene fluoride (PVDF) membrane was
fabricated via coating polydopamine (PDA)-silane (3-aminopropyltrimethoxysilane,
APTMS) hybrid layer as a building block layer, followed by alkoxysilane hydrolysis
induced cationic guanidine compounds (CGC) grafting. The CGC modified membrane
showed comparable pure water permeability with the pristine membrane, but
presented efficient antibacterial activity against both S. aureus and E.
Coli. The grafting of CGC inhibited cell attachment on the membrane surface
and significantly alleviated membrane flux decline during the filtration experiment,
i.e. ~20 % flux decline of CGC modified membrane compared to ~50% flux decline
of the unmodified membrane. The biofilm formation on the membrane surfaces was further
investigated using confocal laser scanning microscope (CLSM). The result
revealed that less live bacteria were observed on the CGC modified membrane in
comparison to the pristine membrane, indicating the excellent biofouling
mitigation function of CGC. Moreover, the PDA/APTMS building block layer
enhanced the stability of the CGC layer during harsh environmental conditions.
This novel CGC grafted membrane shows great potential for water and wastewater
treatment application for biofouling mitigation.

Keywords:
Antibiofouling, cationic guanidine compounds, polydopamine/silane hybrid layer,
membrane filtration, wastewater treatment