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Spatial distribution and environmental characterization of sediment-associated metals from middle-downstream of Xiangjiang River, southern China 总被引:1,自引:0,他引:1
The contamination and environmental risk assessment of the toxic elements in sediments from the middle-downstream (Zhuzhou—Changsha
section) of the Xiangjiang River in Hunan Province of China were studied. The results show that As, Cd, Pb and Zn are major
contaminants in sediments, and average concentrations of these elements significantly exceed both the Control Standards for
Pollutants in Sludge of China (GB4284-84) for agricultural use in acidic soils and the effect range median (ERM) values. The
average concentrations of As, Cd and Pb in the river water slightly exceed the limit of Surface Water Environment Quality
Standard (GB3838—2002). The concentrations of As and Cr in depth profiles extensively change, but slight changes are observed
in Pb and Zn. Cd and Zn in most sediment samples can easily enter the food-chain and bring possible ecotoxicological risk
to organisms living in sediments according to the risk assessment code. 相似文献
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A greenhouse experiment was conducted to elucidate the growth changes and tissues anatomical characteristics of giant reed
(Arundo donax L.), a perennial rhizomatous grass, which was cultivated for 70 d in soils contaminated with As, Cd and Pb. The results show
that giant reed rapidly grows with big biomass of shoots in contaminated soil, possessing strong metal-tolerance with limited
metal translocation from roots to shoots. When As, Cd and Pb concentrations in the soil are less than 254, 76.1 and 1 552
mg/kg, respectively, plant height and dried biomass are slightly reduced, the accumulation of As, Cd and Pb in shoots of giant
reed is low while metal concentration in roots is high, and the anatomical characteristics of stem tissues are thick and homogeneous
according to SEM images. However, plant height and dried biomass are significantly reduced and metal concentration in plant
shoots and roots are significantly increased (P<0.05), the stems images become heterogeneous and the secretion in vascular bundles increases significantly when As, Cd and
Pb concentrations in the soil exceed 334, 101 and 2 052 mg/kg, respectively. The giant reed is a promising, naturally occurring
plant with strong metal-tolerance, which can be cultivated in soils contaminated with multiple metals for ecoremediation purposes. 相似文献
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Environmental availability and profile characteristics of arsenic, cadmium, lead and zinc in metal-contaminated vegetable soils 总被引:2,自引:0,他引:2
Environmental availability and profile characteristics of arsenic (As), cadmium (Cd), lead (Pb) and zinc (Zn) were studied in contaminated vegetable soils from the Pb/Zn mining and smelting areas in Hunan Province of China, and the potential environmental risks of these metals were also assessed. The results show that the concentrations of As, Cd, Pb and Zn in vegetable soils are higher than the levels of Soil Environmental Quality of China (GB15618-1995). The mobility of metals in soil profiles is mainly characterized by the low pH and organic matter content of soil. The major part of As, Cd, Pb and Zn is restricted to the upper soils and the contamination of these metals in soils is significantly influenced by the long-term Pb/Zn mining and smelting activities. Based on the results from the BCR sequential extraction, the fraction of Cd in the soil profiles is predominantly existed in the acid-extractable form and the large amount of Pb is closely associated with reducible fraction. The environmental availability of Cd and Pb is predominantly higher than that of As and Zn in the soil profiles, suggesting Cd and Pb have more huge potential risk for human health and surrounding environment. 相似文献
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