The response of a shallow hypertrophic lake to innovative restoration measures - Uzarzewskie Lake case study

摘要

The aim of nitrate treatment as a restoration method is to bring about a reduction of the high potential reactivity of sediments by the oxidation of biodegradable organic matter. As a consequence, oxygen uptake by sediments is reduced, sulphate reduction is lowered, hydrogen sulphide formation diminished and iron present in sediments binds phosphorus (P) effectively. This approach was applied in Uzarzewskie Lake, where innovative nitrate treatment of sediments was proposed through the diversion of subsurface waters to the lake hypolimnion. Nitrate-rich and oxygenated water from two tributaries was directly delivered to the hypolimnion through pipelines in order to increase redox potential and eliminate sediments as a P source. Research on selected physico-chemical and biological water characteristics was conducted in the years 2005-2015 to determine the results of restoration measures.