Abstract
Antimony ore mining and antimony compounds application have contributed to a certain degree of antimony pollution in the environment, and posed risks to human health and the ecosystems. In order to alleviate this problem, the zeolite-supported nanoscale zero-valent iron (Z-ZVI) composite material was prepared by liquid phase reduction method, and its removal efficiency of Sb(Ⅲ) and Sb(Ⅴ) was studied. Scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the composite material before and after the reaction, and the impact of different material ratios, initial pH values of solution and inorganic anions on the adsorption efficiency for Sb(Ⅲ) and Sb(Ⅴ) was studied. The results show that: (1) Z-ZVI has a high specific surface area (54.54 m2/g) and reactive activation, it can effectively adsorb and reduce high-valent antimony. (2) Under the conditions of pH=7 and 1.0 g/L Z-ZVI, the adsorption efficiency of 20 mg/L of Sb(Ⅲ) and Sb(Ⅴ) reaches 88% and 62%, respectively after four hours of reaction. The adsorption process conforms to the pseudo-second order kinetic equation and the Freundlich adsorption model. (3) The removal rate of Sb(Ⅲ) is not greatly affected by pH, but the removal rate of Sb(Ⅴ) decreases as the initial pH increases. The final pH value of the solution after the reaction is higher than the initial pH. (4) XRD and XPS characterizations show that Sb adsorption and reduction occur simultaneously during the Sb treatment, and the oxidation of Fe0 is accompanied by the reduction of high-valent antimony. Antimony-containing iron oxides are finally formed. (5) In the simulated groundwater adsorption and desorption experiments with relatively low antimony concentration, the removal rate of Sb(Ⅲ) and Sb(Ⅴ) can reach up to 96%. After adsorption, the antimony concentration can be reduced to 0.01 mg/L, and the desorption capacity is much less than the adsorption capacity. The study indicates that Z-ZVI materials can effectively remove Sb(Ⅲ) and Sb(Ⅴ) in polluted water, which has certain value for the practical application of the materials in groundwater remediation.
Translated title of the contribution | Removal of Sb(Ⅲ) and Sb(Ⅴ) in Water by Zeolite-Supported Nanoscale Zero-Valent Iron |
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Original language | Chinese (Traditional) |
Pages (from-to) | 139-149 |
Number of pages | 11 |
Journal | Research of Environmental Sciences |
Volume | 36 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2023 |
Keywords
- adsorption
- antimony
- nanoscale zero-valent iron(nZVI)
- zeolite