Effect of chemical fertilizers on the transport of Escherichia coli, Pseudomonas aeruginosa and Salmonella infantis through sand columns.

Five commercial fertilizers, Amfos, ammonium sulfate, Kamex, Kieserit and NPK affected the transport of Escherichia coli, Pseudomonas aeruginosa and Salmonella infantis in sand columns. The percentage of cells transported through and without fertilizers during a 2-h period was species-dependent (0.56 for S. infantis, 3.1 for E. coli and 12.4 for P. aeruginosa). The cell transport was enhanced by Kamex for all strains tested, whereas Amfos was found to decrease the transport of E. coli and S. infantis cells. A mathematical model revealed a relationship between the transport of cells and the pH of the sand columns with fertilizers. Columns in which the pH was decreased by the fertilizers exhibited a higher retention of cells. This points to the existence of physico-chemical surface interactions between cells and sand particles.