Marine bacterial biofilm formation and its responses to periodic hyperosmotic stress on a flat sheet membrane for seawater desalination pretreatment
2013
Katebian, Leda | Jiang, Sunny C.
Cartridge and membrane biofouling is a significant challenge for the seawater desalination industry. Current cleaning methods remain inefficient or potentially damaging to the membrane. This research characterized marine bacterial biofilm formation and further examined if periodic hyperosmotic shocks to the surface of a filter membrane would reduce bacterial biofilm and prevent membrane fouling. A lab-scale biofouling detector system was developed using an eight-channel pump to deliver simultaneous flow rates through eight 5μm pore size, 25mm diameter nitrocellulose membrane filters. A marine Alteromonas strain isolated from a desalination pilot plant was used as the model biofouling agent. The results showed the 30% NaCl shock produced a hyperosmotic stress that maintained the membrane permeability and flow rate while the control and DI H₂O treated filters did not. Confocal Laser Scanning Microscopy results illustrated that the periodic 30% NaCl shocks slowed the biofilm maturation process by inducing cell mortality and reducing the biofilm thickness. Scanning Electron Microscopy results showed the salinity shock also reduced the coverage of extracellular polysaccharides in the treated biofilm matrix.
显示更多 [+] 显示较少 [-]