Low pressure membranes are used for filtration in water treatment systems due to the small footprint they require and the high-quality water they produce. However, the efficiency of these membrane systems is challenged by fouling, the process in which contaminants in the water adhere to the membrane surface, decreasing energy efficiency and shortening membrane lifespan. Bacterial fouling is especially problematic as the biofilms that develop significantly increase the pressure required to maintain the same rate of water production. Additionally, biofilms are resistant to traditional membrane cleaning. Membrane surfaces can be modified with polydopamine, a chemical with the same functional groups as the adhesive proteins mussels release. This modification occurs under mild conditions and confers a hydrophilic character to the membrane, decreasing the attraction between bacteria and the membrane surface. Additionally, the polydopamine coating is reactive and reduces silver nitrate to antibacterial silver nanoparticles upon exposure, embedding the nanoparticles in the polydopamine layer. Polydopamine modification has been shown to decrease the initial rate of bacterial attachment to polymeric membrane surfaces. However, this decrease in short term attachment has not been clearly linked to longer term improvements in membrane performance. In this work, we explore the effects of polydopamine and silver nanoparticle modification as we filter synthetic wastewater inoculated with <i>Pseudomonas aeruginosa</i> through the membrane. We will measure the rate of water production over five days of filtration. After filtration, we will use confocal microscopy to characterize the architecture of the developed biofilms, including the distribution of live cells, dead cells, and extracellular polymeric substances. We will evaluate the performances of base polysulfone membranes, polydopamine modified membranes, and polydopamine/silver nanoparticle modified membranes by comparing their associated rates of water production and biofilm properties. Elucidating these outcomes will inform the use of polydopamine/silver nanoparticle modification in real membrane treatment systems.<br/>

Effects of modifying low pressure membranes with bioinspired polydopamine and silver nanoparticles on biofilm formation

254th National Meeting (2017)

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