Improvement in the Hydrochemical Regime of Small Urban Water Bodies under Conditions of Artificial Aeration (on the Example of Lake Telbin)

摘要

Small water bodies located within urban territories are often subjected to the influence of anthropogenic load, which manifests itself in the deterioration of their hydrochemical regime, eutrophication, and intensive development of phytoplankton. Dissolved oxygen deficiency and the formation of anaerobic zones in the hypolimnion of the above-mentioned water bodies are environmental hazards. The artificial aeration of small water bodies is one of the ways of the improvement in their oxygen regime, which was demonstrated on the example of Lake Telbin located within the territory of Kiev. The influence of artificial aeration on the state of the water was judged from such significant indices as water temperature, pH value, dissolved oxygen content, the content of inorganic forms of nitrogen and phosphorus, and the content of some metals (Fe, Mn, Cu, Zn, and Pb). In the absence of artificial aeration, dissolved oxygen deficiency is registered in the lake from early spring until late autumn. Under anaerobic conditions at the depths of more than 2-3 m, the concentration of ammonium, inorganic phosphorus, iron, and manganese incoming from bottom sediments significantly increases. Under conditions of artificial aeration, the state of oxygen regime is improved; dissolved oxygen deficiency is observed in deeper layers of water (5.5-6.5 m), whereas high concentrations of the above mentioned chemical components are registered only in the near-bottom layer of water. The efficiency of aeration depends on a depth of aerator submission, and also on its operating conditions.