>>506427Well seeing as you're not satisfied with that source:
Studying sand, charcoal, foam and bark filters:
"The TTCF analyses indicated a 1–2 log10 reduction in bacteria in all filters except for the foam. As E. coli was included in the group of organisms analysed, the results indicate that at least some reduction can be expected for E. coli in the filters."
Further:
"The reduction in TTFC in the bark, charcoal, foam and sand filters was 2.4±0.5, 1.3±0.6, 0.6±0.2 and 1.3±0.5 log10, respectively, giving mean concentrations of 1.6×103, 4.6×103, 5.0×104 and 5.7× 103 CFU mL−1 in the effluent. Thus, the reduction in TTFC in the filters ranged between 74 and 99 %
(Table 3). Enterococcus spp. were not present above the detection limit in the greywater influent or in bark filter effluent, but were detected to be present in effluent from charcoal, foam and sand in concentrations of 100±0, 475±450 and 175±95 CFU mL− 1, respectively"
TTFC stands for thermotolerant faecal coliforms.
Charcoal and sand both show a 91% (+/- 11%) reduction in TTFC levels.
Dalahmeh, S. S., Pell, M., Vinnerås, B., Hylander, L. D., Öborn, I., Jönsson, H. (2012) Efficiency of Bark, Activated Charcoal, Foam and Sand Filters in Reducing Pollutants from Greywater, /Water, Air & Soil Pollution/, 223(7), pp. 3657–3671
