Cation-exchange equilibrium and mass balance in the lichen Umbilicaria muhlenbergii

Equilibrium studies on the thallus of U. muhlenbergii (Ach.) Tuck. confirmed that the mass balance of the exchange of Ni 2+ for Sr 2+ , Sr 2+ for Tl + , and Sr 2+ for H + was consistent with a cation-exchange mechanism of metal-ion uptake.