Publications (2)0 Total impact
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Article: [Evaluation of phytoavailability of zinc and cadmium in contaminated soils by a short sequential extraction procedure].
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ABSTRACT: Cultivated soils and maize samples from heavy metal contaminated locations affected by zinc smelting activities were collected in Hezhang County, Guizhou Province. Chemical fractions of zinc and cadmium (extracted by 0.01 mol x L(-1) CaCl2 and 0.005 mol x L(-1) DTPA) were evaluated by using a short three-step sequential extraction procedure. Results showed that Zn and Cd in soil were dominated by residual fraction, while the CaCl2 extractable and DTPA extractable fraction are only accounted for 0.63%, 3.91% for Zn, and 10.94%, 10.13% for Cd, respectively. Correlation analyses demonstrated that soil CaCl2 extractable metals were not correlated with maize metal concentrations, whereas the DTPA extractable fraction, residual fraction and total Zn and Cd concentrations were correlated significantly with the metal concentrations in maize roots, stems and leaves. These results indicated that CaCl2 extractable fraction may not pay important role on metal phytoavailability in the studied soils. While DTPA extractable fraction and total metal concentrations can be employed to evaluate metals phytoavailability.Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 05/2006; 27(4):770-4. -
Article: Atmospheric Deposition-Carried Pb, Zn, and Cd from a Zinc Smelter and Their Effect on Soil Microorganisms
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ABSTRACT: Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years but ceased in 2000, in Magu Town, Guizhou Province, China were selected to examine Pb, Zn, and Cd concentrations and their fractionation along a distance gradient from a zinc smelter, and to study the possible effects of Pb, Zn, and Cd accumulation on soil microorganisms by comparing with a reference soil located at a downwind distance of 10 km from the zinc smelter. Soils within 1.5 km of the zinc smelter accumulated high levels of heavy metals Zn (508 mg kg−1), Pb (95.6 mg kg−1), and Cd (5.98 mg kg−1) with low ratios of Zn/Cd (59.1–115) and Pb/Cd (12.4–23.4). Composite pollution indices (CPIs) of surface soils (2.52–15.2) were 3 to 13 times higher than the reference soils. In metal accumulated soils, exchangeable plus carbonate-bound fractions accounted for more than 10% of the total Zn, Pb, and Cd. The saturation degree of metals (SDM) in soils within 1.5 km of the smelter (averaging 1.25) was six times higher than that of the reference soils (0.209). A smaller soil microbial biomass was found more frequently in metal accumulated soils (85.1–438 μg C g−1)thanin reference soils (497 μg C g−1), and a negative correlation (P< 0.01) of soil microbial biomass carbon to organic carbon ratio (Cmic/Corg) with SDM was observed. Microbial consumption of carbon sources was more rapid in contaminated soils than in reference soils, and a shift in the substrate utilization pattern was apparent and was negatively correlated with SDM (R = −0.773, P< 0.01). Consequently, dust deposited Pb, Zn, and Cd in soils from zinc smelting were readily mobilized, and were detrimental to soil quality mainly in respect of microbial biomass.Pedosphere.
