Virus removal by unsaturated wastewater filtration:effects of biofilm accumulation and hydrophobicity

摘要

Enhanced treatment of septic tank effluent can improve the hydraulic function and performancenof infiltration systems and constructed wetlands. By intermittent spray application of septic tankneffluent onto a coarse-grained filter media, an unsaturated flow regime beneficial for pathogennremoval is created. A column filtration study showed an increase in PRD-1 removal by time ofnoperation with corresponding biofilm accumulation in the filter material. The same increasednremoval was observed for 1mm polystyrene beads, irrespective of their hydrophilic/hydrophobicnsurface properties. A control experiment with sorption of 1 mm hydrophobic and hydrophilicnpolystyrene beads to different glass surfaces with hydrophobic and hydrophilic properties indicatenthat mechanisms other than hydrophobic interactions may govern the rate of attachment to thenfilter media. For a given volumetric flow-rate in the columns, the presence of biofilm altered thenhydrodynamic characteristics and this resulted in increased retention time and particle removal.