Microfiber filtration of lake water: Impacts on TEP removal and biofouling development

Biofouling is a major and very expensive problem for the water industry. An Amiad Automatic Microfiber Filter (AMF) was tested as a pretreatment for biofouling growth inhibition using a lake water source. The filtration efficiency of the AMF in reducing Transparent Exopolymer Particles (TEP) and chlorophyll (Chl) levels in the feedwater was measured in 24 experiments during 2010-2011. These experiments showed significant reductions in TEP (mean 47 ± 21%), Chl (mean 90 ±6%), total suspended solids (67 ±7%), NTU turbidity (89 ± 5%), and >3 lm particle count (93± 4%) concentrations in the AMF filtered water. In parallel, four tests were conducted over one year to compare details of biofilm development on the surfaces of Robbins devices exposed for 30days to AMF filtered or unfiltered lake water. Confocal laser scanning microscopy (CLSM) showed that the volume and thickness of extracellular polymeric substances of the biofilm that formed on the surfaces was markedly inhibited when the feedwater was filtered through the AMF. Taken together, these results show that microfiber filtration has good potential as a pretreatment technology upstream of surfaces sensitive to biofouling.