Fig. 1. Removal efficiency for E. coli and C. jejuni in replicate 10-cm columns under the following conditions: uncoated quartz sand with 10 mM KCl, uncoated quartz sand with 1 mM KCl, Fe-coated sand with 10 mM KCl, and Al-coated sand with 10 mM KCl. Error bars represent one standard deviation of the mean.