Factors affecting ammonium capture by some Victorian lignites

HighlightsVictorian lignites were assessed for their NH4+ retention capacity using adsorption isotherms and 15N tracing.NH4+ adsorption capacity of lignites increased (up to 3-fold) with pH, especially from pH 5 to 7.Biological immobilisation did not play a substantial role in the NH4+ retention capacity of the lignites.pH-dependent NH4+ adsorption was the dominant means by which lignite retained NH4+.