Preservation of water quality in accumulation Lake Rovni: the estimate of the emission of phosphorus from inundation area

The emission of phosphorus from various ecochemical types of soil (arable land, forest, meadow and orchard) was investigated in order to preserve the quality of water in a future accumulation lake (54 millions cubic meters and 230 ha) Rovni near Valjevo (Serbia and Montenegro). Samples were taken from three depths: 0–10, 10–20 and 20–30 cm. In order to extract different forms of phosphorus (known as NH4Cl-P or available-P, Al-P, Fe-P, reducible-P, occluded-P and Ca-P) all samples were subjected to sequential extraction according to the modified method of Chang and Jackson. Most of phosphorus was bound to iron. This fraction contained more than 80% of inorganic P and it is expected that in the future accumulation lake the chemodynamics of phosphorus and iron will be closely related. This conclusion is in agreement with the results of two independent extraction procedures. Inorganic phosphorus is in a greater extent associated with Si than with Al. These results are important for the provision of good water quality in the future accumulation Lake Rovni near Valjevo (Serbia and Montenegro).

The specific release of phosphorus from soil into river water depends on the ecochemical type of soil and amounts after 30 day of contact time between 30 and 50 mg/m2 of soil surface. This P-release is decreasing with the depth of soil sampling profile: for the depth of 20–30 cm the P-release decreased more than 80% in comparison to the top soil. Therefore, the removal of 20 cm of arable land and 10 cm of other land types will considerably diminish of P-release into the lake water. The results of sequential extraction indicate that phosphorus bound to iron (Fe-P) is the dominant form of inorganic phosphorus in all investigated ecochemical types of soil. Therefore, it is expected that in the future accumulation lake the chemodynamics of phosphorus and iron will be closely related. This conclusion is in [1] R. Vollenweider, Technical Report OECD, DAS/ CSI, OECD, Paris, 1968, pp. 68–27. [2] H.L. Golterman and N.T. Oude, in: Hutzinger (Ed.), The Handbook of Environmental Chemistry, Springer, Berlin Heidelberg, 5A, 1991, pp. 79–124. [3] A. Kleeberg, B. Nixdorf and J. Mathes, Lakes Reservoirs: Res. Manag., 5 (2000) 23–33. [4] V. Ruban, J.F. López-Sánchez, P. Pardo, G. Rauret, N. Muntau and Ph. Quevauviller, J. Environ. Monit., 3 (2001) 121–125. [5] V. Ruban, J.F. López-Sánchez, P. Pardo, G. Rauret, N. Muntau and Ph. Quevauviller, J. Environ Monit., 1 (1999) 151–156. [6] J. Schoer and D. Eggersgluess, Chemical Forms of Heavy Metals in Sediments and Suspended Matter of Weser, Elbe and Ems Rivers, SCOPE/ UNEP Sonderband, Heft 52, Hamburg, 1982, pp. 667–685. [7] W. Salomons and U. Foerstner, Metals in Hydrocycle, Springer, New York, p. 350. [8] P. Polic and P.A. Pfendt, J. Serb. Chem. Soc., 56 (1991) 241–248. [9] P.R. Hesse, A Textbook of Soil Chemical Analysis, Chemical Pub. Co., 1971, pp. 255–500. [10] S.C. Chang and J. Jackson, Soil Sci. Soc. Am., 22 (1957) 290. [11] J. Murphy and J.P. Riley, Anal. Chim. Acta, 27 (1962) 31–39. [12] S.C. Chang, W.K. Chu and K.T. Erh, Soil. Sci., 102 (1966) 44. [13] P.R. Hesse, A Textbook of Soil Chemical Analysis, Chemical Pub. Co., 1971, p. 297. [14] D. Manojlovic et al., unpublished results.