Evaluation of novel backwashable cartridge filters: Efficacy and sustainability
One of the important aspects of desalination pre–treatment is the removal of particles from feedwater. This is typically accomplished using a combination of gross filtration and cartridge filtration. Cartridge filters are typically single-use products, and their replacement can represent a significant portion of a desalination plant's operating budget. This research evaluated the performance of a new type of cartridge filter that is backwashable and aims to reduce the overall cost to desalination facilities and provide cleaner water. Two sets of filters were evaluated (in triplicate) with respect to particle removal efficiency and hydraulic efficiency. The initial set included four types of cartridge filters that vary in geometry (size and layers), wall thickness (0.5-1.7 cm), and average pore size (15, 20, and 25 µm). The second set were second generation filters that were modified to improve hydraulic performance. The water being filtered was finished water from the El Paso Water Utility's Kay Bailey Hutchison (KBH) desalination plant with ground silica as the source of particles. Particle removal efficiency was evaluated by turbidity, as well as particle size distribution analysis using a Multisizer 4 Coulter Counter. Particle removal efficiency, which ranged from 94% to greater than 99%, was observed to be slightly sensitive to the reported average pore size. Second-generation filters showed consistency between filter triplicates, as well as varying degrees of filtrate particle reduction as a function of filter dimensions. Consistency in the Cartridge Filter Fouling Index (CFFI) was observed between backwashes, up to four consecutive backwashes (i.e., maximum tested). The second set of filters showed significant improvement in specific flux while maintaining superior filtrate particle reduction in comparison to the control cartridge filters.
Brown, Michelle Renee, "Evaluation of novel backwashable cartridge filters: Efficacy and sustainability" (2013). ETD Collection for University of Texas, El Paso. AAI1539923.