Biati Aida, Karbassi Abdulreza R, Keyhani Zahra
Department of Environmental Science, Graduate Faculty of Environment and Energy, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran,
Environ Monit Assess. 2014 Jul;186(7):4289-97. doi: 10.1007/s10661-014-3698-5. Epub 2014 Mar 14.
In the present investigation, bulk and chemical partitioning of elements (Cu, Mn, Ni, Zn, Fe, Ca) together with organic matter as a loss in ignition in the Qarechay River bed sediments have been studied. The concentration of metals in Qarechay River bed sediments is governed by the geological units of the study area. The study of anthropogenic portion shows that a small proportion of elemental concentration belongs to this phase. However, Mn has a large portion of anthropogenic sources (43 %). Also, Mn has a share of 13.6 % in sulfide fractions. This result indicates that Mn is a highly mobile element and can easily enter the water column. The presence of Mn in sulfide fraction might be indicative of initial stages of conversion of oxidation state into reduction in Qarechay River. Share of metals in anthropogenic portion is in the following order: Mn (43 %) > Cu (19 %) > Zn (10 %) > Ni (3 %) > Fe (0 %). Organic metallic bonds are not significantly present in the study area. Geochemical index (I geo), pollution index (I poll), enrichment factor (EF), and pollution load index (PLI) values are indicative of a clean environment throughout the river course. These values are in well agreement with results of chemical partitioning data. Eventually, based on the results of chemical partitioning, regional standard of elements for Qarechay River bed sediments has been established.
在本次调查中，研究了卡雷恰伊河床沉积物中元素（铜、锰、镍、锌、铁、钙）的总量和化学分配情况，以及作为灼烧减量的有机质。卡雷恰伊河床沉积物中金属的浓度受研究区域地质单元的控制。人为部分的研究表明，元素浓度的一小部分属于这一阶段。然而，锰有很大一部分来自人为源（43%）。此外，锰在硫化物组分中的占比为13.6%。这一结果表明锰是一种高度易迁移的元素，能够轻易进入水柱。锰在硫化物组分中的存在可能表明卡雷恰伊河中氧化态向还原态转化的初始阶段。人为部分中金属的占比顺序如下：锰（43%）＞铜（19%）＞锌（10%）＞镍（3%）＞铁（0%）。研究区域内有机金属键并不显著。地球化学指数（Igeo）、污染指数（Ipoll）、富集因子（EF）和污染负荷指数（PLI）值表明整个河道环境清洁。这些值与化学分配数据的结果高度一致。最终，基于化学分配结果，建立了卡雷恰伊河床沉积物元素的区域标准。
