Effects of dissolved organic matter from the rhizosphere of the hyperaccumulator Sedum alfredii on sorption of zinc and cadmium by different soils
| Autor: | Donald L. Sparks, Zhenzhen Di, Tingqiang Li, Xiaoe Yang |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
China
Environmental Engineering Health Toxicology and Mutagenesis Sedum Soil Desorption Botany Soil Pollutants Environmental Chemistry Hyperaccumulator Organic matter Biomass Waste Management and Disposal chemistry.chemical_classification Rhizosphere Dose-Response Relationship Drug biology Chemistry Sorption Hydrogen-Ion Concentration biology.organism_classification Pollution Zinc Metals Environmental chemistry Sedum alfredii Loam Adsorption Calcareous Cadmium |
| Zdroj: | Journal of Hazardous Materials. 192:1616-1622 |
| ISSN: | 0304-3894 |
| DOI: | 10.1016/j.jhazmat.2011.06.086 |
| Popis: | a b s t r a c t Pot experiments were conducted to investigate the changes of the dissolved organic matter (DOM) in the rhizosphere of hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) of Sedum alfredii and its effects on Zn and Cd sorption by soils. After planted with HE, soil pH in the rhizosphere reduced by 0.5-0.6 units which is consistent with the increase of DOM. The hydrophilic fractions (51%) in DOM from the rhizosphere of HE (HE-DOM) was much greater than NHE-DOM (35%). In the presence of HE-DOM, Zn and Cd sorption capacity decreased markedly in the following order: calcareous clay loam > neutral clay loam > acidic silty clay. The sorption isotherms could be well described by the Fre- undlich equation (R 2 > 0.95), and the partition coefficient (K) in the presence of HE-DOM was decreased by 30.7-68.8% for Zn and 20.3-59.2% for Cd, as compared to NHE-DOM. An increase in HE-DOM concen- tration significantly reduced the sorption and increased the desorption of Zn and Cd by three soils. DOM derived from the rhizosphere of the hyperaccumulating ecotype of S. alfredii could significantly reduce metal sorption and increase its mobility through the formation of soluble DOM-metal complexes. |
| Databáze: | OpenAIRE |
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