Institute of Chemistry of the Academy of Sciences of Moldova Larisa Postolachi chemjm_correspondence@yahoo.com mEDRA 20161225

07 10.19261/cjm.2016.11(1).02 http://www.cjm.asm.md/sites/default/files/article_files/ChemJMold201611(1)_21-26_Sandu.pdf Institute of Chemistry of the Academy of Sciences of Moldova mEDRA 01 Institute of Chemistry of the Academy of Sciences of Moldova MD 07 1857-1727 JB 07 2345-1688 JD 11 1 June 2016 01 201606 2 11 21 26 6 1 A01 Maria Sandu Sandu, Maria Maria Sandu 2 A01 Anatol Tarita Tarita, Anatol Anatol Tarita 3 A01 Raisa Lozan Lozan, Raisa Raisa Lozan 4 A01 Natalia Zgircu Zgircu, Natalia Natalia Zgircu 5 A01 Elena Mosanu Mosanu, Elena Elena Mosanu 6 A01 Tatiana Goreacioc Goreacioc, Tatiana Tatiana Goreacioc 7 A01 Alexandru Zlotea Zlotea, Alexandru Alexandru Zlotea 8 A01 Anna Comarnitchi Comarnitchi, Anna Anna Comarnitchi 9 A01 Iulia Sidoren Sidoren, Iulia Iulia Sidoren 10 A01 Sergiu Turcan Turcan, Sergiu Sergiu Turcan 11 A01 Adrian Tarita Tarita, Adrian Adrian Tarita 01 eng 20 Lake Beleu; self-purification capacity; nitrification process; BOD5; COD-Cr 01 According to the Regulation on monitoring and systematic evidence of the surface and groundwater status, the Beleu Lake is included in the network of surface waters state monitoring in the Republic of Moldova. The research results have marked a low value of the self-purification capacity for Beleu Lake water, between 0.12 and 0.19, which is of 1.2-2 times lower than those from Prut River (0.25), correlating positively with the values of BOD5, COD-Cr and the time of biochemical oxidation of ammonium ions. The oxidation of ammonium into nitrite (NH4+(NH3) → NO2-) in the nitrification process in lake water (collected in November 2014) takes place about 25 days and the process NO2- → NO3- being more than 35 days. The period of nitrification is about 2 times higher than in lake water collected in 2015 and 2.8-3.0 times higher than those of the model with water from Prut River. 201606 2016 Institute of Chemistry of the Academy of Sciences of Moldova 1857-0461 Academos Eremia, A. 4(35) 147 05 2014 Hydronyms of Prut basin. Left tributaries of the river. 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