Phosphorus fractionation in lake sediments – Lakes.pdf

Phosphorus fractionation in lake sediments – Lakes Volvi and Koronia, N. Greece A. Kaiserli, D. Voutsa *, C. Samara Environmental Pollution Control Laboratory, Chemistry Department, Aristotle University, GR-54006 Thessaloniki, Greece Received 10 July 2001; received in revised form 4 October 2001; accepted 17 October 2001 Abstract Sediments from two lakes, the meso-to-eutrophic Volvi and the hypertrophic Koronia, located in N. Greece were examined on the basis of P-fractionation. In both lakes, the rank order of P-fractions was HCl–P NaOH–P BD–P NH4Cl–P. The loosely sorbed phosphorus eNH4Cl–PT represented 1% of the sedimentary inorganic phosphorus, while the reductant phosphorus (BD–P) ranged 5–6%. The calcium bound phosphorus (HCl–P) showed considerable contribution (59–74%) to the sedimentary inorganic P-loads. The metal oxide bound phosphorus (NaOH– P) was higher in the hypertrophic (30–35%) than in the meso-to-eutrophic system (19–28%). Fine-sized sediments exhibited significantly higher concentrations of HCl–P in Volvi and NH4Cl–P in Koronia. Sampling month had sig- nificant effect in variance of most P-fractions and other sediment features in both lakes. Use was also made of mul- tivariate statistics to identify the factors which influence the sedimentary phosphorus. NaOH–P was the most reactive fraction in Lake Volvi. Iron compounds and organic matter seem to play a significant role in regulating this labile P-budget. NH4Cl–P was the more reactive fraction in Lake Koronia which was influenced by sedimentation of P-absorbed on clay/silt fine particles.
2002 Elsevier Science Ltd. All rights reserved. Keywords: Grain size; Lakes; PCA; Phosphorus; P-fractions; Sediment; Trophic status 1. Introduction Phosphorus has been recognized as the most critical nutrient limiting lake productivity. The main sources of phosphorus in lakes are external point and non-point sources such as rainfall, runoff, soil leaching, industrial and municipal effluents. Moreover, there