Chair of Water Supply, Sewerage, Water and Wastewater Treatment, Faculty of Hydraulic Engineering, University of Architecture, Civil Engineering and Geodesy, 1 Hr. Smirnenski Blvd., 1046 Sofia, Bulgaria.
Chair of Analytical Chemistry, Faculty of Chemistry and Pharmacy, Sofia University "St. Kliment Ohridski", 1 J. Bourchier Blvd., 1164 Sofia, Bulgaria.
Molecules. 2021 Dec 11;26(24):7517. doi: 10.3390/molecules26247517.
The temporal dynamics of anthropogenic impacts on the Pchelina Reservoir is assessed based on chemical element analysis of three sediment cores at a depth of about 100-130 cm below the surface water. The Cs activity is measured to identify the layers corresponding to the 1986 Chernobyl accident. The obtained dating of sediment cores gives an average sedimentation rate of 0.44 cm/year in the Pchelina Reservoir. The elements' depth profiles (Ti, Mn, Fe, Zn, Cr, Ni, Cu, Mo, Sn, Sb, Pb, Co, Cd, Ce, Tl, Bi, Gd, La, Th and U) outline the Struma River as the main anthropogenic source for Pchelina Reservoir sediments. The principal component analysis reveals two groups of chemical elements connected with the anthropogenic impacts. The first group of chemical elements (Mn, Fe, Cr, Ni, Cu, Mo, Sn, Sb and Co) has increasing time trends in the Struma sediment core and no trend or decreasing ones at the Pchelina sampling core. The behavior of these elements is determined by the change of the profile of the industry in the Pernik town during the 1990s. The second group of elements (Zn, Pb, Cd, Bi and U) has increasing time trends in Struma and Pchelina sediment cores. The increased concentrations of these elements during the whole investigated period have led to moderate enrichments for Pb and U, and significant enrichments for Zn and Cd at the Pchelina sampling site. The moderately contaminated, according to the geoaccumulation indexes, Pchelina Reservoir surface sediment samples have low ecotoxicity.
基于对 Pchelina 水库三个深度约为 100-130 厘米的沉积物核心的化学元素分析，评估了人为影响的时间动态。通过测量 Cs 活性来识别与 1986 年切尔诺贝利事故相对应的层位。获得的沉积物核心定年结果给出了 Pchelina 水库的平均沉积速率为 0.44 cm/年。元素的深度分布（Ti、Mn、Fe、Zn、Cr、Ni、Cu、Mo、Sn、Sb、Pb、Co、Cd、Ce、Tl、Bi、Gd、La、Th 和 U）表明，Struma 河是 Pchelina 水库沉积物的主要人为污染源。主成分分析揭示了与人为影响相关的两组化学元素。第一组化学元素（Mn、Fe、Cr、Ni、Cu、Mo、Sn、Sb 和 Co）在 Struma 沉积物核心中具有随时间增加的趋势，而在 Pchelina 采样核心中没有趋势或呈减少趋势。这些元素的行为是由 1990 年代 Pernik 镇工业剖面变化决定的。第二组元素（Zn、Pb、Cd、Bi 和 U）在 Struma 和 Pchelina 沉积物核心中具有随时间增加的趋势。这些元素在整个研究期间的浓度增加导致了 Pb 和 U 的中等富集，以及在 Pchelina 采样点的 Zn 和 Cd 的显著富集。根据地质累积指数，被中度污染的 Pchelina 水库表层沉积物样品具有低生态毒性。
