Fig. 3. Predicted effluent concentrations curves (semi-log plot of relative effluent concentrations as a function of time) for oocysts in 710-µm sand at distances of 25, 50, and 100 cm from the inlet. Predictions were obtained using the attachment–detachment (Model-Att/Det) and the attachment–detachment–straining (Model-Att/Det/Str) conceptual models. Model parameters were determined by fitting (Table 2) to the experimental soil column data.