Factors affecting ammonium capture by some Victorian lignites.

HighlightsVictorian lignites were assessed for their NH 4 + retention capacity using adsorption isotherms and 15 N tracing. NH 4 + 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 NH 4 + retention capacity of the lignites.pH-dependent NH 4 + adsorption was the dominant means by which lignite retained NH 4 + .