This work investigates polyvinylidene fluoride (PVDF) membrane modification to enhance its hydrophilicity and antibacterial properties. PVDF membranes were coated with nanoparticles of titanium dioxide (TiO₂-NP) and silver (AgNP) at different concentrations and coating times and characterized for their porosity, morphology, chemical functional groups and composition changes. The results showed the successfully modified PVDF membranes containing TiO₂-NP and AgNP on their surfaces. When the coating time was increased from 8 to 24 h, the compositions of Ti and Ag of the modified membranes were increased from 1.39 ± 0.13 to 4.29 ± 0.16 and from 1.03 ± 0.07 to 3.62 ± 0.08, respectively. The water contact angle of the membranes was decreased with increasing the coating time and TiO₂-NP/AgNP ratio. The surface roughness and permeate fluxes of coated membranes were increased due to increased hydrophilicity. Antimicrobial and antifouling properties were investigated by the reduction of Escherichia coli cells and the inhibition of biofilm formation on the membrane surface, respectively. Compared with that of the original PVDF membrane, the modified membranes exhibited antibacterial efficiency up to 94% against E. coli cells and inhibition up to 65% of the biofilm mass reduction. The findings showed hydrophilic improvement and an antimicrobial property for possible wastewater treatment without facing the eminent problem of biofouling.

Groundwater serves as an important resource for people in the Mekong Delta, but its quality has been continuously declined from human activities. Current status of the groundwater quality needs to be evaluated for sustainable groundwater resource management. This study aimed to evaluate the groundwater quality for drinking purposes in the Mekong Delta, Vietnam, using multivariate statistical methods and integrated-weight water quality index. Data comprised 8 water quality parameters (pH, total hardness, nitrate (NO₃⁻), iron (Fe), lead (Pb), mercury (Hg), arsenic (As), and coliforms) obtained from 64 observation wells in An Giang province, Dong Thap province, and Can Tho city, were analyzed by cluster analysis (CA), principal component analysis (PCA), and integrated-weight water quality index (IWQI). The results indicated that most parameters were within standards while excessive hardness and Fe contamination were found in some regions. More than 80% of samples were detected with serious coliform contamination. The CA results revealed that groundwater quality heavily depend on geological locations with 4 clusters of the sampling locations. Three principal components obtained from PCA could explain 77.2% of the groundwater quality variation. The IWQI values ranging from 4 to 2761 classified groundwater quality as excellent (53.1%), good (25%), poor (9.4%), very poor (4.7%), and undrinkable (7.8%), which were associated with coliform contamination. These findings have provided insights into the groundwater quality status in the region, which can benefit in developing a water protection strategy.