Abstract

Monitoring the pollution status of freshwater resources is an important step in sustainable planning. This study aimed to determine the distribution and sources of metals in the sediments of the transboundary eastern Anatolian/Caucasus region Kura river as well as its ecological risk level. Surface sediment samples were collected from eight sites along the human disturbance gradient. Multi-element analyses of the collected samples were performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Chlorophyll degradation product (CDP) analysis was performed spectrophotometrically. OC analysis was carried out using the titration method. The data obtained were evaluated using the indices of enrichment factor, geo-accumulation, modified hazard quotient and ecological contamination index and potential ecological risk. The average content of metals in the sediment at the eight sites was of the following descending order from highest to lowest: Al > Mn > Zn > V> Ni > Cr > Cu > Co > Pb > As > Cd > Tl > Hg. According to the distribution of raw metal values, urbanization is not the only factor controlling metal distribution. Adsorption processes and organic material content also emerge as an important factor. Enrichment factor values were of the following order: T1 > Pb > Mn > Hg > Cr > Co > Cd > Ni > As > Zn > Al > Cu > V. Results revealed that the sources of Cu, V and Al were lithogenic, in contrast to Tl, Pb, Mn, Hg, Cr, Co, Cd, Ni, and As, thus pointing to human-induced accumulation. According to the potential ecological risk index, these elements have the potential to create medium-to-high level ecological risks and were substantially of atmospheric origin. The ecological contamination index is also consistent with these findings in terms of risk level. A municipal waste stream, fossil fuel burning and a cement plant operating in close proximity also appeared to be the possible sources.

摘要

监测淡水资源的污染状况是可持续规划的重要一步。本研究旨在确定东安纳托利亚/高加索地区跨界库拉河沉积物中金属的分布和来源及其生态风险水平。沿人为干扰梯度从八个地点收集了表层沉积物样本。使用电感耦合等离子体质谱 (ICP-MS) 对收集的样品进行多元素分析。叶绿素降解产物 (CDP) 分析采用分光光度法进行。使用滴定法进行OC分析。利用富集因子、地理积累、修正危险商数、生态污染指数和潜在生态风险等指标对获得的数据进行评估。8个站点沉积物中金属元素的平均含量从高到低依次为：Al>Mn>Zn>V>Ni>Cr>Cu>Co>Pb>As>Cd>Tl>Hg。从原金属价值的分布来看，城市化并不是控制金属分布的唯一因素。吸附过程和有机物质含量也成为一个重要因素。富集因子取值顺序为：T1 > Pb > Mn > Hg > Cr > Co > Cd > Ni > As > Zn > Al > Cu > V。与 Tl、Pb、Mn、Hg、Cr、Co、Cd、Ni 和 As 形成对比，因此指向人为引起的积累。根据潜在生态风险指数，这些因素有可能造成中等到高水平的生态风险，并且主要来自大气。生态污染指数在风险水平方面也与这些发现一致。城市废物流、化石燃料燃烧和附近运营的水泥厂似乎也是可能的来源。