Sediment dynamics and heavy metal pollution history of the Cruhlig Lake (Danube Delta, Romania)

摘要: This is the first study reporting recent sedimentation rates data (e.g. past 120-150 years) for Cruhlig Lake situated in Danube Delta. The aim of this to analyse using (210)Pb dating method and identifying heavy metal pollutants their variability time. Five sediment cores were taken with a gravity corer - after drying sliced samples-physical parameters, organic material inorganic carbon content determined. total was measured via (210)Po by alpha spectrometry, while supported (226)Ra (trough short life (222)Rn daughters) HPGe detectors. Heavy metals determined ICP-MS; from 64 elements, only exceeding values Al, As, Cd, Co, Cs, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Ni, Pb Zn are discussed. After applying CRS model, ages calculated. average rate 0.21 ± 0.02 g/cm(2)y, Minimum (0.05 0.003 g/cm(2)y) registered along eastern shoreline lake before 1913, maximum recorded due flooding 2006 western side (1.34 0.12 g/cm(2)y). Recent divide into three areas: secluded near shore part (0.63 0.07 g/cm(2)y), centre (0.92 0.05 dynamic area, where most transport takes place (1.13 0.01 pattern proves be very sensitive fluvial discharge fluctuations. building Iron Gate dams (1972 1985) had negative impact on decreasing it 58.74%, 1989 these grew 2.25 times. received quantity rich 1992 3 y, which settled mostly part. Values up five times higher 1980 5 y lake, Cr Ni twice as high marine substrate. As show increasing 150% 2 throughout whole surface lake.