Change in the forms of metals during photochemical oxidation of organo-mineral compounds in swamp and river waters

The interaction of organic matter with metal ions plays a key role in the migration of metals in aquatic ecosystems, the formation of natural water quality, toxicity and bioavailability of metals. Sunlight irradiation of swamp and river waters transforms dissolved organic matter, degrading it to low molecular weight compounds up to mineralization and simultaneously coagulating compounds >0.22 μm. As a result of the reduction and subsequent oxidation of Fe, as well as changes in its bond with organic matter, the formation of hydroxides of Fe(III) occurs. These hydroxides can form large, stabilized by organic ligands organo-mineral compounds >0.22 μm, with which Mn, Co, Cd can co-precipitate.