ABSTRACT
The review of own and literary data confirming essentially important role of oxidation-reduction processes with participation of hydrogen peroxide and reduced sulfur water-soluble compounds for formation of the biological full value of the natural water environment and normal functioning of aerobic aquatic ecosystems is submitted. Hydrogen peroxide is the integral participant chemical-biological circulation of molecular oxygen: it is formed as an intermediate product at the 4th an electronic photo-oxidation of molecules of water in the processes of photosynthesis and at the 4th electronic reduction of O2 to water in oxidation processes (including, in processes of cellular respiration). Reduced sulfur compounds (RSH) are formed in the anaerobic environment, mainly, as a result of microbiological processes of a sulfate-reduction, or are dumped in natural waters as a part of sewage.
120As established by us, among the reduced-sulfur, the special danger for aerobic aquatic ecosystems represents by water-soluble substances that effectively interact with hydrogen peroxide and at the same time are stable against oxidizing action of oxygen.
At excess receipt of similar substances reduced sulfur there can arise quasi-reduced conditions in the water when molecular oxygen is present at the water in “norm”(in a thermodynamic sense the water environment is in an oxidizing state), but instead of hydrogen peroxide there are detected substances which are effectively interacting with H2O2. Similar transition from a normal oxidizing state to quasi-reduced is followed by emergence in the water environment of toxic conditions for aerobic water organisms with intensive water exchange with the external environment, in particular, for larvae of fishes before their transition to branchiate breath and also creation the conditions in water favorable for mass development (“blossoming”) of blue-green seaweed (cyanobacteria) and of accompanying them pathogenic microflora.
