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1.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(10): 2963-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26904851

ABSTRACT

So far, many investigations had been made on the concentration and species distribution of heavy metals in aquatic environments. However, there are only a few studies on heavy metals in upper reaches of the Yellow River, especially in Gansu, Ningxia and Inner Mongolia sections. We have literatures related to the Yellow River, in this work, we remarkably discussed about the contents, speciation and potential risks of Cd, Pb, Cr, V, Co, Ni, Cu, and Zn in surface sediments from 12 sampling sites in Gansu, Ningxia, and Inner Mongolia sections of the Yellow River of China in 2011 year wet season by high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) and sequential extraction procedure of BCR method. The results indicated that the metals contents were arranged as Cr > V > Zn > Cu > Ni > Pb > Co > Cd in all sites. Comparing with the background value of soil in local section, Cd showed the highest level at S5 (1.30 µg x g(-1)), which was almost 13 times higher than the background value (0.103 µg x g(-1)). Pollution assessment indicated that Cd presented a strong polluted status with the geo-accumulation index (I(geo)) value of 3.08 at S5, moderately to strong polluted status with the I(geo) ranged from 2.02 to 2.90 in Inner Mongolia section (S1-S4). Moreover, enrichment factor (EF) showed that all heavy metals in these sediments have been influenced by anthropogenic activities. According to potential ecological risk index (RI), S5 and S3 demonstrated high ecologic risk of heavy metals, while other sampling sites showed moderately ecological risk. The results of BCR exhibited that Cd was the most available metal, followed by Co and Ni, while V and Cr were unavailable in the sediments. Risk assessment code (RAC) exhibited high risk for Cd at S1-S4 and very high risk at S5, while medium risk for Ni and Co at all sites. The results and conclusions may be important information and therefore of interest to the relevant departments of the governments.

2.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(3): 798-803, 2013 Mar.
Article in Chinese | MEDLINE | ID: mdl-23705457

ABSTRACT

In the present paper, BCR sequential extraction and high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS) were performed to analyze the speciation contents of 14 kinds of rare earth elements (REE) in the surface sediments from 12 sampling sites (S1-S12) in Gansu, Ningxia and Inner Mongolia Sections of Yellow River, and REE fractionation were also studied. The results indicated that the contents of REE in 12 sediment samples werethe same order. The average contents of 14 rare earth elements were in this order: Ce(66.4)>La(35.8)>Nd(28.6)>Pr(7.88)>Sm(5.87) >Gd(5.01)>Dy (4.53)>Yb(2.86)>Er(2.51)>Eu(1.31)>Ho(0.856)>Tb(0.760)>Tm(0.428)>Lu(0.404), which were similar to the Chinese soil background. The residual fractions of all elements were present at the highest percentages(71.9%-93.9%), which indicated that the bioavailability or environmental impact was low. The percentage of reducible fraction was the lowest, ranged from 0. 20% to 3. 87% with the mean value of 0.83%, while the oxidizable fraction percentage(7.61%) was close to acid-soluble fraction(7.69%). But in Maqu (S12), oxidizable percentage (16.1%) was significantly higher than the acid-soluble fraction (1.73%). Correlation analysis showed that there was a significant positive correlation between total organic carbon (TOC) content and oxidizable percentage, and the correlation coefficients were between 0.763 and 0.914. REE fractionation results showed that: the contents of REE in surface sediments of Gansu, Ningxia and Inner Mongolia Sections of Yellow River were mainly from soil weathering, with light-REE enrichment and Eu depletion. The chondrite-normalized curve implied that La and Ce in Jinshawan (S8) and Baotou-Dengkou (S1) and heavy REE at all the sampling points might have external REE sources.

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