Project proposal is aimed on complex in-depth research on the interaction between humic acids and ionic compounds (e. g. organic dyes, surfactants or heavy metal ions). To fulfil this complex task and to be able to describe the way of formation of these interactions, the reactivity of native HA will be compared with their selectively modified equivalents (selectively blocked carboxylic functional groups by methylation). The formation of the interactions between different (original and modified) humic acids and ionic compounds will be studied either by transport experiments (diffusion, dialysis) as well as by advanced instrumental methods such as Fluorescence Correlation Spectroscopy, light scattering techniques and differential UV-VIS spectroscopy. The most important output from the project can be found in complex description of mutual interconnection of transport phenomena and formation of interactions between HA and ionic species in respect to basic humic acids structural parameters (e.g. content of free carboxylic functional groups, molecular weight, particle size, acidity).

Keywords
humic substances, International Humic Substances, Society (IHSS), dialysis, methylation, spectroscopic techniques