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SM ISO690:2012 SPATARU, Petru, TRANCALAN, Ana, POVAR, Igor. Study of stable nitrogen forms in natural surface waters in the presence of mineral substrates. In: The International Conference dedicated to the 55th anniversary from the foundation of the Institute of Chemistry of the Academy of Sciences of Moldova, 28-30 mai 2014, Chișinău. Chișinău, Republica Moldova: Institutul de Chimie al AȘM, 2014, p. 183. |
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The International Conference dedicated to the 55th anniversary from the foundation of the Institute of Chemistry of the Academy of Sciences of Moldova 2014 | ||||||
Conferința "The International Conference dedicated to the 55th anniversary from the foundation of the Institute of Chemistry of the Academy of Sciences of Moldova" Chișinău, Moldova, 28-30 mai 2014 | ||||||
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Pag. 183-183 | ||||||
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The impact of gravel, polymer film and aeration of the reduced nitrogen forms in surface |
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<?xml version='1.0' encoding='utf-8'?> <oai_dc:dc xmlns:dc='http://purl.org/dc/elements/1.1/' xmlns:oai_dc='http://www.openarchives.org/OAI/2.0/oai_dc/' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xsi:schemaLocation='http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd'> <dc:creator>Spătaru, P.A.</dc:creator> <dc:creator>Trancalan, A.I.</dc:creator> <dc:creator>Povar, I.G.</dc:creator> <dc:date>2014</dc:date> <dc:description xml:lang='en'><p>The impact of gravel, polymer film and aeration of the reduced nitrogen forms in surface<br />waters was studied in a previous paper [1]. Authors [1] found that gravel, polymer film and<br />aeration caused the acceleration of decreasing ammonia content in water. Gravel and polymeric<br />film speeded up the oxidation process of ammonia, while the aeration diminished its amount. In<br />this paper, the ammonium ion oxidation in the water samples, in the presence and absence of<br />mineral substrates, has been investigated. The presence of granite and expanded clays speeds the<br />oxidation of ammonium ion by 12 days in the case of downstream of the South Racovat River.<br />The time of oxidation of ammonium ion in the presence of these substrates is 7 days, while in<br />their absence is 20 days. The ammonium ion oxidation for samples with granite has an<br />insignificant delay in comparison with expanded clays, while the formation and decrease of the<br />nitrite ion concentration is favored for clays by 3-4 days with the maximum difference in the<br />concentration of 1 mg/L. The water models from the Isnovat River, in which the impact of<br />granite, ceramsite, calcium carbonate and their combination have been investigated, demonstrate<br />that separate granite and ceramsite as well as their combination have a significant influence on<br />the dynamics of nitrification. The addition of calcium carbonate slows down the oxidation of<br />reduced forms of nitrogen. The adding up of CaCO3 causes a larger effect on more polluted<br />water samples in the Ungheni section after WWTP than on less polluted ones in the Sculeni<br />section. On the other hand, the largest effect is registered for the highly polluted by cationic<br />detergents waters in the Varancau section of the Nistru River downstream of the Soroca city. In<br />the water samples without substrates, both the NH4<br />+ oxidation and the NO3<br />- reduction to the<br />NO2<br />- ions take place to their greater extent of nitrite formation (4-5 mg/L). The ammonium<br />oxidation is practically blocked by adding CaCO3 to the water samples. For the samples taken<br />from the Nistru River near to the Bursuc village the effect of calcium carbonate is smaller, but<br />still noticeable. In the case of the Cunicea village vicinity, where the river water is not polluted<br />by detergents, the nitrification dynamic of ammonia and nitrite ions with and without CaCO3 is<br />more or less similar.<br />As a result, granite and expanded clay substrates as well as their combination have a<br />comparable effect in supporting the oxidation of nitrogen reduced forms in natural surface<br />waters. Concomitantly, CaCO3 blocks abovementioned process, essentially for highly polluted<br />waters. Our research proves again that the organic pollutants, especially the cationic ones,<br />produce a noticeable impact on the ammonia oxidation process dynamics in natural waters.<br />References:<br />[1] Sandu, M.; Spataru, P.; Arapu, T.; Lupascu, T. Biochemical oxidation – a pathway for<br />ammonia removal from aquatic systems. In: „Methods and Techniques for Cleaning-up<br />Contaminated Sites”, Springer, 2008, 137-143.</p></dc:description> <dc:source>The International Conference dedicated to the 55th anniversary from the foundation of the Institute of Chemistry of the Academy of Sciences of Moldova () 183-183</dc:source> <dc:title>Study of stable nitrogen forms in natural surface waters in the presence of mineral substrates</dc:title> <dc:type>info:eu-repo/semantics/article</dc:type> </oai_dc:dc>