Functionalization of bacterial cellulose-based nanofibrous surfaces with antibacterial moieties for membrane biofouling mitigation

Nanofibrous membranes have garnered considerable attention for filtration purposes owing to their capability to endure high fluid flow rates while effectively removing micro- and nano-sized pollutants from solutions. However, biofouling remains a significant issue in the nanofibrous membrane processes as it leads to reduced permeate flux, increased energy costs, and shortened lifespan of membranes. Here we report the functionalization of nanofibrous bacterial cellulose (BC) membrane by simple impregnation for filtration of bio-effluents, including organic matter and microbe containing solutions. Antibacterial and anti-biofouling properties were imparted to the BC nanofibers by a custom-tailored silane with picolinic acid named TCPA. Functionalized BC membranes with silver nanoparticles were used as control to compare filtration, antibacterial and anti-biofouling properties. Cross-flow filtration tests showed that functionalization with silane did not compromise the membrane permeation characteristics, instead, it supported in flux enhancement due to the increase in the hydrophilic character of the silane-treated BC. In a series of bacterial challenge tests, the functionalized membranes significantly reduced E. coli adhesion compared to pristine bacterial cellulose membranes and the control membrane, demonstrating strong anti-biofouling potential in settings where long-term exposure to high microbial loads is anticipated. This study highlights the potential of tailored functionalization of nanofibrous membranes with TCPA as filters for water treatment systems, offering a combination of anti-biofouling and intrinsic antibacterial advantages. • Ex-situ functionalization of bacterial cellulose for anti-biofouling • Excellent bacterial retention and antibacterial property under pressure driven filtration • Enhanced flux recovery of more than 95 % in organic rich aqueous medium