Movement and Survival of Bacteria in Porous Media

Floodwater and flowing rivers contain bacteria and viruses from sewage and manure which may percolate to aquifers and contaminate groundwater. This study investigated the behaviour of bacteria and viruses introduced with tap and other waters in sand columns. The adsorption and desorption from sand of Escherichiacoli, Enterobacteraerogenes, Staphylococcusaureus, Streptococcusfecalis and Bacillusmegaterium were examined. The capability of Salmonellatyphimurium, Salmonellatyphi and Shigellaflexneri of surviving in natural organic matter accumulated in sand was examined, as was the survival of poliovirus 1 and colibacteriophage in sand columns. Size and morphology of the bacteria had no influence on the filtration efficiency. No difference was found between Gram positive and Gram negative bacteria. Survival of the enteropathogenic bacteria in the rich organic matter in the column ranged up to not more than about twenty days. However, Salmonellatyphimurium survived much longer. Poliovirus 1 was less resistant to the adverse conditions of the sand column as compared with f2 bacteriophage. However, both viruses behaved in the sand column like the bacteria, but survived for over 100 days.