Paper Title
Solutions and Methods of Prognosis and Control of the Water Eutrophication in Izvoru Muntelui – Bicaz Lake, Romania

Abstract
The adverse effects of nutrient enrichment of surface waters, ‘aquatic eutrophication’, have been identified as a major environmental issue at national and international levels. There is also a lack of consistent methodologies for assessing and controlling eutrophication. This strategy, which was produced following extensive consultation with interested parties, promotes a more co-ordinate framework for action and a partnership approach to eutrophication management. In our country there exist over 450 storage lakes with volumes over 1 000 000 m3, on the whole a gross volume of about 13,5 milliards m3. Many of these, especially big storage lakes created significant negative effects on environment, some even catastrophic damages and losses of human lives. Characteristic for lakes, especially for the artificial ones, is the evolution process of water quality, with the tendency of their eutrophication, fact with special problems regarding water treatment technologies. This phenomenon is caused by the over limits increasing of nutrients concentrations (nitrogen, phosphorus) from lake’s waters, substances involved through agricultural fields watering, fields on which were applied fertilizers. This paper presents researches carried out during the period 2014 – 2019 regarding the evolution of the eutrophication process in the Izvoru Muntelui – Bicaz Lake, from hydrological basin of Siret River, the biggest artificial lake in Romania. The fight against eutrophication regards both causes, and its effects. The strategies used were aimed at reducing excessive nutrients intake in lake, also treatment of the specific effects of the eutrophication process. Following the application of a series of physical-mechanical, chemical, biological, and bacteriological methods, through interventions on the reception basin, on lake itself, on sediments, energetic factors or by bio-manipulation, the results showed that only the applying of a combination of combined methods leads to efficient results in reducing the degree of water eutrophication in lake. Keywords - Eutrophication, Modelling, Surface Water Quality, Monitoring, Trophicity