| 1 | Distribution,source identification and risk assessment of selected metals in sediments from freshwater lake显示文摘This study is based on the assessment of distribution,source apportionment and risk assessment of selected metals in freshly deposited sediments from freshwater lake,Pakistan.Composite sediments were collected and processed to assess Ca(NO_3)_2-extractable and acid-extractable levels of the metals in the sediments using flame atomic absorption spectrophotometry.Enrichment factors(EF),geoaccumulation indices(I_(geo)),contamination factors(C_f) and degree of contamination(C_(deg)) were computed to estimate the degree of contamination.The potential ecological risk was assessed using sediment quality guidelines and mean-ERM-quotient(m-ERM-Q).On the average basis,acid-extractable metals followed the decreasing concentration order:Ca>Mg>Fe>K>Mn>Na>Sr>Zn>Pb>Cr>Co>Cu>-Li>Cd,whereas,the Ca(NO_3)_2-extractable levels were:Na>Ph>Cd>Sr>Co>Cr>K>Mg>-Cu>Zn>Li>Ca>Fe>Mn.The highest Ca(NO_3)_2 extractable concentrations were observed for Na,Pb and Cd,while that of Ca,Fe and Mn were the least.EF showed very high and extremely high enrichment of Pb and Cd,respectively,while Ca,Co,Cr,Li,Mg,Mn,Sr and Zn manifested moderate enrichment:the I_(geo) results revealed moderate to strong and strong to extreme pollution for Pb and Cd,respectively;and the C_f study showed moderate,considerable and very high contamination by Co,Pb and Cd,respectively.The C_(deg) revealed very high degree of contamination in the sediments as a whole.Principal component analysis(PCA) and cluster analysis(CA) showed considerable anthropogenic contributions of Cd,Pb,Co,Mn,K,Zn and Li in the sediments.Measured levels of Cd and Pb exceeded ERL values,manifesting occasional adverse biological effects to the dwelling biota.Moreover,the mERM-Q study manifested 21%probability of toxicity in the sediments. | Javed Iqbal Munir H.Shah Nazia Shaheen | 2015 | International Journal of Sediment Research2015，30，3： | 2 |
| 2 | 西南印度洋中脊活动与非活动热液区沉积物元素地球化学特征对比显示文摘龙旂热液区与断桥热液区分别是西南印度洋中脊典型的活动与非活动热液区。为研究两区内表层沉积物地球化学特征,对共59件表层沉积物进行了元素地球化学测试,对其进行物质组分、富集系数与R型聚类等分析。结果表明:两区内普遍含较高的Ca、Sr、Ba等生源元素和Fe、Mg、Si、Al等围岩元素,而构造、围岩和热液活动等因素的不同,使两区沉积物的元素地球化学特征存在差异。龙旂区沉积物出现了源于超基性围岩的组分并体现在元素聚类组合中,其沉积物中热液富集相关元素Cu、Zn、Fe和Co等。断桥区更高的生源元素含量可能指示其热液活动停止后,主要受生物沉积作用的影响,该区热液相关元素与基性围岩联系紧密,表现出Pb与W的明显富集。 | 宋备 苏新 吕士辉 倪建宇 廖时理 陶春辉 胡茂康 李世云 于翀涵 | 2020 | 现代地质2020，34，1： | 1 |
| 3 | Characterisation of sediments polluted by acid mine drainage in the northeast of Algeria显示文摘现在的学习在 Essouk 河里调查作文和沉积的矿物学,在近似在上游的 2km 在黑人 Kamber 采矿地区在阿尔及利亚的东北定位了 Guenitra 水库。自从 1976,矿被放弃,但是酸的排水水仍然是河污染的来源。粉末 X 光检查衍射(XRD ) ,与精力扫描电子显微镜学(SEM ) 散分析(EDX ) , X 荧光分析和红外线的光谱学分析被用来描绘在采矿自河附近在区域在各种各样的地点取样的表面沉积。获得的结果证明沉积的作文被铁和硫主要统治。在矿的附近, jarosite 和 schwertmannite 是必需品猛抛。下游地,沉积被铁 oxyhydroxydes 的各种各样的阶段与吸附的硫酸盐的存在形成。 | Chahrazed BOUKHALFA Mounia CHAGUER | 2012 | International Journal of Sediment Research2012，27，3： | 1 |
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