Features of the Accumulation of Heavy Metals by Macrophyte Algae of Salt Lakes in Zabaykalsky Krai

Of all currently known pollutants, heavy metals (HMs) are of particular concern. A study of the content of HMs in water and macroalgae in salt lakes of the southeast of Zabaykalsky krai, which do not experience pollution from industrial enterprises, has been carried out. The aim is to study the features of the accumulation of HMs in soda and sulfate-type lakes. The rivers and lakes differ in mineralization (from 0.45 to 45.29 g/dm3) and pH (from 7.80 to 9.55). With the increase in water mineralization, the contents of the main ions increase, with the exception of calcium, and the chemical type of HCO3 Ca–Mg changes to HCO3 Na–Mg. A similar pattern, but with a more pronounced salinization process, is noted for soda lakes. The value of mineralization and pH in the waters of soda lakes is higher than that of river lakes. The sulfate type differs from soda by a higher mineralization of water, but a lower pH value. With increasing salinity, $${\text{CO}}_{3}^{{2 - }}$$ and $${\text{HCO}}_{3}^{ - }$$ do not accumulate in Cladophora fracta, Enteromorpha intestinalis, Stigeoclonium flagelliferum, Spirogyra sp. ster., or Rhizoclonium riparium. The rivers and lakes of this area have low concentrations of most HMs. The maximum number is revealed in a saltier lake with an oxidizing environment (Lake Barun-Shivertui). A comparative assessment of the content of HMs in macroalgae of salt lakes with macroalgae of fresh and marine waters has shown comparability with their Clarke values; therefore, the concentrations will be background for salty water bodies of the southeast of Transbaikalia. Macroalgae accumulate less metal in total with increasing salinity, but react differently to the pH of the water. In soda water bodies, with an increase in pH, the total value of the accumulation coefficient decreases, while in sulfate water bodies, on the contrary, it increases. The linear dependence of the values of the HM accumulation coefficient in macroalgae containing Men+ in water and with positively charged MeCl+ and $${\text{MeHCO}}_{3}^{ + }$$ complex ions indicates the possibility of their assimilation by plants. At the same time, the inverse dependence of the accumulation coefficient of heavy metals (AC HMs) in plants with FA–Me, Me(OH)3, MeCO3, and $${\text{AsO}}_{4}^{{3 - }}$$ indicates a negative effect of these complexes on the bioavailability of metals.