The aquatic chemistry of iron is an important issue since iron is a micronutrient for the growth of phytoplankton. Its concentration in surface waters involves many environmental aspects, from the quality of a particular water to the control of atmospheric carbon dioxide. Dissolved iron can exist in water as ferrous and ferric iron, and the equilibrium between these two forms, as well as the precipitation and solubilization of iron, depends on many natural and anthropic factors. We studied the variation for an year of Fe(II) and total iron concentration into Poarta Alba - Midia Navodari Canal, an artificial surface water which connects Danube River with Black Sea. The results indicate a high iron concentration in surface water and a seasonal variation of iron concentration and speciation, which can be correlated with the oxidable matter content.
. N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, second edition, Greenwood Butterworth-Heinemann, 1997.
. X. Pu, B. Hu, Z. Jiang, C. Huang, Speciation of dissolved iron(II) and iron(III) in environmental water samples by gallic acid-modified nanometer-sized alumina micro-column separation and ICP-MS determination, Analyst 130 (2005) 1175-1181. DOI: 10.1039/b502548f
. X. Zhu, R. Zhang, S. Liu, Y. Wu, Z. Jiang, J. Zhang, Seasonal distribution of dissolved iron in the surface water of Sanggou Bay, a typical aquaculture area in China, Marine Chemistry 189 (2017) 1-9. DOI: 10.1016/j.marchem.2016.12.004
. P.W. Boyd, M. J. Ellwood, The biogeochemical cycle of iron in the ocean, Nature Geoscience 3 (2010) 675-682. DOI: 10.1038/ngeo964
. A.M. Aguilar-Islas, M.J.M. Séguret, R. Rember, K.N. Buck, P. Proctor, C.W. Mordy, N.B. Kachel, Temporal variability of reactive iron over the Gulf of Alaska shelf, Deep-Sea Research II 132 (2016) 90-106. Doi: 10.1016/j.dsr2.2015.05.004
. W. Xing, G. Liu, Iron biogeochemistry and its environmental impacts in freshwater lakes, Fresenius Environmental Bulletin 20 (2011) 1339 - 1345.
. G. Zhuang, Z. Yi, G.T.Wallace, Iron(II) in rainwater, snow, and surface seawater from a coastal environment, Marine Chemistry 50 (1995) 41-50. DOI: 10.1016/0304-4203(95)00025-M
. A. Jones-Lee, G. F. Lee, Role of iron chemistry in controlling the release of pollutants from resuspended sediments, Journal of Remediation 16 (2005) 33-41.
. F.J. Millero, W. Yao, J. Aicher, The speciation of Fe(II) and Fe(III) in natural waters, Marine Chemistry 50 (1995) 21-39. DOI: 10.1016/0304-4203(95)00024-L
. X. Liu, F.J. Millero, The solubility of iron in seawater, Marine Chemistry 77 (2002) 43- 54.
. J.D. Hem, W.H. Cropper, Survey of ferrous-ferric chemical equilibria and redox potentials, in “Chemistry of iron in natural water”, Washington, U.S. Govt. Print. Off., 1962.
. W. Stumm, G.F. Lee, Oxygenation of ferrous iron, Industrial and Engineering Chemistry 53 (1961) 143-146.
. D. E. Archer, A model of the iron cycle in the ocean, Global Biogeochemical Cycles 14 (2000) 269-279.
. U. Schmedtje (overall coordinator and editor), The Danube river basin district, prepared by International Commission for the Protection of the Danube River (ICPDR) in cooperation with the countries of the Danube River Basin District, International Commission for the Protection of the Danube River Vienna International Centre, Vienna 2005.
. D.J. Pietrzyh, C.W. Frank, Analytical Chemistry, Academic Press, New York, 1979.
. J.O. Hibbits, W.F. Davis, M.R. Menke, The determination of iron with l, 10-phenanthroline, Talanta 8 (1961) 163-165. DOI:10.1016/0039-9140(61)80050-7
. S. Dobrinas, S. Birghila, A. Dumbrava, Determination of Fe, Cu, Cr from surface waters by standard addition method, Ovidius University Annals of Chemistry 16 (2005) 51 - 53.
. A. Dumbrava, S. Birghila, Analysis of some metal levels in Danube river water, Environmental Engineering and Management Journal 8 (2009) 219-224.
. I. Enache, S. Birghila, A. Dumbrava, The Danube River water quality characteristics in the Braila Town, Ovidius University Annals of Chemistry 20 (2009) 146-152.
. S. Birghila, A. Dumbrava, S. Dobrinas, Determination of heavy metals from ecosystem of Vrancea Mountains, Environmental Engineering and Management Journal 3 (2004) 695 - 700.
. A. Dumbrava, S. Dobrinas, S. Birghila, Water quality characteristics along the course of the Danube River. I. The Rasova area, Ovidius University Annals of Chemistry 18 (2007) 85 - 90.
. A. Dumbrava, S. Dobrinas, S. Birghila, Water quality characteristics along the course of the Danube River. II. The Harsova area, Ovidius University Annals of Chemistry 18 (2007) 124 - 131.
. STAS 3002-85 - Drinking water. Determination of oxidable organic substances (in Romanian).
. P. Atkins, T. Overton, J. Rourke, M. Weller, F. Armstrong, Shriver and Atkins' Inorganic Chemistry, fifth edition, Oxford University Press, 2010.
. H.H. Huang, The Eh-pH diagram and its advances, Metals 6 (2016) 23. DOI: 10.3390/met6010023
. P.J. Worsfold, M.C. Lohan, S.J. Ussher, A.R. Bowie, Determination of dissolved iron in seawater: A historical review, Marine Chemistry 166 (2014) 25-35. DOI: 10.1016/j.marchem.2014.08.009
. Minister Order 161/2006 for the approval of the “Normative on the classification of surface water quality in order to establish the ecological status of the water bodies” (in Romanian).
. American Public Health Association, Standard Methods for the Examination of Water and Wastewater, 19th ed., 1995.
. B. Morgan, O. Lahav The effect of pH on the kinetics of spontaneous Fe(II) oxidation by O2 in aqueous solution - basic principles and a simple heuristic description, Chemosphere 68 (2007) 2080-2084. DOI:10.1016/j.chemosphere.2007.02.015
. K.G. Taylor, K.O. Konhauser, Iron in Earth surface systems: a major player in chemical and biological processes, Elements 7 (2011) 83-88. DOI: 10.2113/gselements.7.2.83