Maximum sorption capacity (<i>Q_max</i>) and binding coefficient (<i>k</i>) determined by fitting to the Langmuir model.

<p>Results are shown as mean (standard error). <i>Q_max</i> and <i>k</i> values followed by different lowercase letters within a compound is statistically significant at <i>P≤</i>0.05. ^* Represent only one soil series (Longford). In all other cases, data from three soils series were averaged for each soil order.