engleski

Nitrate concentration in Karašica-Vučica River surface waters

In February 2017 world population has exceeded the number of 7.3 billion [1], what resulted in higher demand for food production and intensification of urbanization. As a result, amount of available cultivated land is decreasing. In order to increase agricultural yield, various types of manure are used, especially nitrogen, which significantly increases yield of high quality agricultural products. However, nitrogen manure is a significant source of soil and water pollution, with highest concentrations of nitrates found in water in areas of intensive agriculture [2]. In this paper, the results of analysis of concentration of nitrates in Karašica-Vučica river surface waters are shown. Nitrates are salts of nitric acid, and a final product of oxidation of nitrogen compounds. They are necessary for algal growth and development of aquatic plants, though concentrations greater than 90 mg/L are toxic for aquatic organisms. Sources of nitrates are various - decomposition of organic matter in sediment, agriculture, sewage. Increased amount of nitrates in drinking water can cause various illnesses (methemoglobinemia and cancer) [3, 4], and also have a negative impact on environment, such as eutrophication of surface waters, which is especially pronounced in lowland rivers of Europe [5]. This paper studies the concentration of nitrates in surface waters of tributary of the river Drava – Karašica-Vučica. Samples were taken over the period of five years, and cover several locations along the river flow (Karašica Crnac- Krčenik, Karašica Črnkovci, Karašica downstream form Valpovo, Vučica Marijančaci, Vučica Petrijevci). [1] http://www.census.gov/popclock/, 6.2.2017. [2] V. Filipović, D. Petošić, Z. Nakić, Hrvatske vode 84 (2013) 119. [3] E.R. Weiner, Applications of Environmental Chemistry, A Practical Guide for Environmental Professionals. CRC Press, Taylor and Francis Group, Boca Raton, 2007, p. 51-57. [4] A.H. Wolfe, J.A. Patz, Ambio, 31 (2002), 120. [5] R.W. Howarth, R. Marino, Limnol. Oceanogr. 51 (2006) 364.

fertilizers ; nitrate concentration ; surface water ; Karašica-Vučica River ; water pollution

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