Gravity-Driven\nMembrane Filtration with Passive Hydraulic\nFouling Control for Drinking Water Treatment: Demonstration of Long-Term\nPerformance at Full Scale

The present study evaluated the performance of a full-scale\ngravity-driven\nmembrane filtration system with passive hydraulic fouling control\n(PGDMF) for drinking water treatment in a small community over a 3-year\nperiod. The PGDMF system consistently met the design flow and regulated\nwater quality/performance parameters (i.e., total coliform, Escherichia coli, turbidity, and membrane integrity).\nThe instantaneous temperature-corrected permeability (TCP) varied\nseasonally, being greater during the winter months. The overall TCP\ndecreased slowly to ∼60% of the initial value by the end of\n3 years, a TCP that is much greater than would have been expected\nwithout passive hydraulic fouling control. Although it was not possible\nto directly link the observed seasonal changes in TCP to potential\nseasonal changes in the biofilm microbiome, the analysis did suggest\nthat the lower TCP during summer months was due to a greater microorganism\nrichness in the feed and presence of filamentous, stalked, and biofilm-forming\nbacteria in the biofilm. Operation with higher trans-membrane pressure\n(i.e., ∼30 vs ∼20 mbar) and more frequent passive hydraulic\nfouling control (i.e., every 12 vs 24 h) enabled a greater flow to\nbe sustained. The study demonstrated the long-term robustness and\nperformance of GDMF with passive hydraulic fouling control for drinking\nwater treatment.