Abstract
This paper discusses preliminary research on using photoinduced luminescence phenomena in determining the structural properties of humic acids extracted from the bottom sediments of two lakes. The lakes examined differ in the hydrochemical parameters of the water body, as well as in the drainage basins surrounding the lakes. Photoinduced luminescence of humic acids was induced with a halogen light of 1500 μmol m-2 s-1 photon flux density. The differences observed are evidence of both the variable qualitative and quantitative contribution of photoluminophors to the structure of the examined humic acids, and of their different photochemical activity. Furthermore, photoinduced luminescence intensity depends on the degree of transformation of the humic acids.