Enhancing the removal of Sb (III) from water:a Fe3O4@HCO composite adsorbent caged in sodium alginate microbeads

To remove antimony (Sb) ions from water, a novel composite adsorbent was fabricated from ferriferous oxide and waste sludge from a chemical polishing process (Fe3O4@HCO) and encapsulated in sodium alginate (SAB). The SAB adsorbent performed well with 80%–96% removal of Sb (III) ions within a concentration range of 5–60 mg/L. The adsorption mechanism of Sb (III) was revealed to be the synergy of chemisorption (ion exchange) and physisorption (diffusion reaction). The adsorption isotherms and kinetics conformed to the Langmuir isotherm and the pesudo-second-order kinetic model. Both initial pH and temperature influenced the adsorption performance with no collapse of microbeads within solution pH range 3–7. Most importantly for practical applications, these microspheres can be separated and recovered from aqueous solution by a magnetic separation technology to facilitate large-scale treatment of antimony-containing wastewater

A critical review of resistance and oxidation mechanisms of Sb-oxidizing bacteria for the bioremediation of Sb(Ⅲ) pollution

Antimony (Sb) is a priority pollutant in many countries and regions due to its chronic toxicity and potential carcinogenicity. Elevated concentrations of Sb in the environmental originating from mining and other anthropogenic sources are of particular global concern, so the prevention and control of the source of pollution and environment remediation are urgent. It is widely accepted that indigenous microbes play an important role in Sb speciation, mobility, bioavailability, and fate in the natural environment. Especially, antimony-oxidizing bacteria can promote the release of antimony from ore deposits to the wider environment. However, it can also oxidize the more toxic antimonite [Sb(III)] to the less-toxic antimonate [Sb(V)], which is considered as a potentially environmentally friendly and efficient remediation technology for Sb pollution. Therefore, understanding its biological oxidation mechanism has great practical significance to protect environment and human health. This paper reviews studies of the isolation, identification, diversity, Sb(III) resistance mechanisms, Sb(III) oxidation characteristics and mechanism and potential application of Sb-oxidizing bacteria. The aim is to provide a theoretical basis and reference for the diversity and metabolic mechanism of Sb-oxidizing bacteria, the prevention and control of Sb pollution sources, and the application of environment treatment for Sb pollution

Study on the migration rules of Sb in antimony ore soil based on HYDRUS-1D

https://egrove.olemiss.edu/aicpa_comm/1198/thumbnail.jp

Mechanism of dissolution and oxidation of stibnite mediated by the coupling of iron and typical antimony oxidizing bacteria

Antimony oxidizing bacteria (SbOB) and iron oxides are the main driving factors to the weathering dissolution and oxidation of stibnite (Sb2S3) waste ore. The characteristics of the dissolution and oxidation process of stibnite in the absence of strain AO-1 and iron oxides, Pseudomonas sp. AO-1-mediated (AO-1-mediated), Fe (Fe, Fe2(SO4)3, and FeS2) -mediated, and coupled-mediated groups (Fe+AO-1, Fe2(SO4)3+AO-1, FeS2+AO-1) under various pH values were examined through sequential batch experiments. The results showed that all the AO-1-mediated, Fe-mediated and coupled-mediated can promote the dissolution and oxidation of stibnite, and the promotion effect increased with the rise of pH. The order of contribution to the dissolution of stibnite under the coupling mediation is as follows: coupling effect (42.4-78.2%) > chemical effect (19.4-56.6%) > biological effect (0.9-2.4%). In addition, the dissolution and oxidation mechanisms of stibnite were further investigated and analyzed in combination with scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). This study has important implications for elucidating the source control and geochemical behavior of antimony pollution in antimony mining areas

Risk assessment of potentially toxic elements pollution from mineral processing steps at Xikuangshan antimony plant, Hunan, China

We evaluated the direct release to the environment of a number of potentially toxic elements (PTEs) from various processing nodes at Xikuangshan Antimony Mine in Hunan Province, China. Sampling wastewater, processing dust, and solid waste and characterizing PTE content (major elements Sb, As, Zn, and associated Hg, Pb, and Cd) from processing activities, we extrapolated findings to assess wider environmental significance using the pollution index and the potential ecological risk index. The Sb, As, and Zn in wastewater from the antimony benefication industry and a wider group of PTEs in the fine ore bin were significantly higher than their reference values. The content of Sb, As, and Zn in tailings were relatively high, with the average value being 2674, 1040, and 590 mg·kg−1, respectively. The content of PTEs in the surface soils surrounding the tailings was similar to that in tailings, and much higher than the background values. The results of the pollution index evaluation of the degree of pollution by PTEs showed that while dominated by Sb, some variation in order of significance was seen namely for: (1) The ore processing wastewater Sb > Pb > As > Zn > Hg > Cd, (2) in dust Sb > As > Cd > Pb > Hg > Zn, and (3) surface soil (near tailings) Sb > Hg > Cd > As > Zn > Pb. From the assessment of the potential ecological risk index, the levels were most significant at the three dust generation nodes and in the soil surrounding the tailings reservoir

Research on the characteristics and mechanism of the cumulative release of Antimony from an Antimony smelting slag stacking area under rainfall leaching

We aimed to study the characteristics and the mechanism of the cumulative release of antimony at an antimony smelting slag stacking area in southern China. A series of dynamic and static leaching experiments to simulate the effects of rainfall were carried out. The results showed that the release of antimony from smelting slag increased with a decrease in the solid-liquid ratio, and the maximum accumulated release was found to be 42.13 mg Sb/kg waste and 34.26 mg Sb/kg waste with a solid/liquid ratio of 1 : 20; the maximum amount of antimony was released within 149–420 μm size fraction with 7.09 mg/L of the cumulative leaching. Also, the antimony release was the greatest and most rapid at pH 7.0 with the minimum release found at pH 4.0. With an increase in rainfall duration, the antimony release increased. The influence of variation in rainfall intensity on the release of antimony from smelting slag was small