Figure 2. Sorption isotherms of NH4 +-N on wheat-straw biochar (W-BC), corn-straw biochar (C-BC) and peanut-shell biochar (P-BC) at different pyrolytic temperatures (Qe: the amount of NH4 +-N sorbed by per unit mass of biochar at equilibrium; Ce: concentration of NH4 +-N in the solution at equilibrium).
Bars indicate standard deviation of three replicates.