Pathogen and indicator organisms removal in artificial greywater subjected to aerobic treatment : comparison of four filter media

Abstract: Treated greywater has a good potential to be used as a source of water. This study analyzes the removal of Salmonella spp., Enterococcous faecalis, bacteriophage ɸX174 and bacteriophage MS2 from greywater by filtration through biochar, bark, activated carbon and mixture of bark and activated carbon. Reduction of pathogen and indicator organisms were studied over a period of 63 days in column experiments (height 65 cm, diameter: 4.3 cm) supplying artificial greywater at a hydraulic loading rate of 0.032 m3 m-2 day-1 and an organic loading rate of 76 g BOD5 m-2 day-1 (240 g COD m-2 day-1). Biochar filters were more effective than other filters in removal of Salmonella spp. (3 log10 reduction) and were less effective in removal of bacteriophages. Bark and mixture filters performed inefficiently in removal of pathogen and indicator organisms (1-2 log10 reduction). High reduction of pathogen and indicator organisms was detected in activated carbon filters within the first half of the experimental period. The reduction was 7 log10 for Salmonella spp., 5 log10 for E. faecalis, 6 log10 for acteriophage фX174 and 3 log10 for MS2. The reduction of Salmonella spp. and ɸX174 correlated to the inflow concentration in all filter media.