Changes in phytoplankton productivity with the introduction of heavy metals into the ecosystem and its subsequent purifi cation with a humic sorbent
Mesoscale modeling experiments simulating water pollution of a freshwater plain reservoir by infusion of a mixture of heavy-metal (Cd, Zn, Cu) salts were conducted. Central to the research was determining the phytoplankton response (in terms of primary production) to the presence of heavy metals in water and to the introduction of a sorbent based on mechanochemically oxidized humic acids. The removal of heavy metals by phytoplankton on the 16th day of the experiment resulted in a decrease in the content of Cd(II) to 62%, Zn(II) to 58%, and Cu(II) to 46% of the initial levels. The use of sorbent under the same conditions led to a decrease in the content of Cd(II) to 21%, Zn(II) to 27%, and Cu(II) to 10% of the initial levels. The sorbent under study does not cause blooming of the reservoir, distinguishing it from sorbents containing humic acids with the native structure of molecules.