The kinetics of oxygen quenching of eosin (E) triplets adsorbed on alumina and concomitant O-1(2) feedback-induced delayed fluorescence (DF) of E, were measured at different O-2 and E concentrations by the diffuse-reflectance laser flash technique. The global kinetic analysis in terms of O-1(2) feedback in which the energy transfer from O-1(2) to E-3 generates E-1* revealed the dependence of kinetic parameters on oxygen content and sample loading which matches the aggregation of E on the surface. The excitation migration in dye and oxygen manifolds is assumed to be involved resulting in high DF efficiency.