Antimony In Sediments Research Articles

Source, Distribution and Potential Risk of Antimony in Water and Sediments of Danjiangkou Reservoir: Impact from Dam.

Danjiangkou Reservoir is the water source of the mid-route of the South-to-North Water Transfer Project. The source, distribution and potential risk of antimony in its water and sediments are rarely reported. In this study, symmetrical investigation results demonstrated that the concentration of antimony in the Han sub-reservoir and water in front of the dam fluctuated at about 0.9 mg L−1, while it was relatively higher and increased with the distance from the dam in Dan sub-reservoir water, with an annual average of 0.93~3.15 mg L−1. In recent years, the concentration of antimony in the Danjiangkou Reservoir showed a downward trend, and the difference between the Han and Dan sub-reservoirs decreased significantly. The antimony in the sediments in the reservoir was primarily derived from the inflowing rivers, and it was higher in the Dan sub-reservoir than in the Han sub-reservoir. The concentration of antimony in the water in the reservoir was considerably higher than the background value in the watersheds, indicating that there is an external input with decreasing input intensity. The content of antimony in the sediments in the reservoir and its inflow rivers was substantially higher than the background value of watersheds, indicating that there is a certain degree of enrichment. In addition, the antimony mining industry in the water source area poses a risk to the water safety of the reservoir. Antimony is not a conventional pollutant. Consequently, the collection of antimony monitoring results is a challenging task. Additionally, this study fills the gap in regional antimony research. Furthermore, the ecological risk assessment of antimony in China is still in its infancy. Unquestionably, the study of the temporal and spatial distribution of antimony concentration will be beneficial for the protection of water sources in relevant regions.

Seasonal antimony pollution caused by high mobility of antimony in sediments: In situ evidence and mechanical interpretation.

Antimony (Sb) mobilization in sediments and its impact on water quality remained to be studied. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) technique were used to measure soluble Sb and labile Sb in sediment-overlying water profiles for a full year in a eutrophic region of Lake Taihu. Results showed that the highest mean concentrations of soluble Sb in overlying water (11.27 and 6.99 μg/L) appeared in December 2016 and January 2017, due to oxidation of Sb(III) to Sb(V) by Mn and Fe oxides, all of which exceeded the surface or drinking water limits set by China, United States and European Union. From April to November 2016, the concentrations of soluble Sb remained low with small monthly fluctuations and mean values ranging from 1.79 to 2.93 μg/L. This was attributed to the predominance of insoluble Sb(III) in sediments under anoxic conditions. The concentration of soluble Sb was slightly higher in summer than in autumn, due to the complexation of Sb(III) with DOM, as shown under anaerobic incubation. The mobility of inorganic Sb in sediments was mostly determined by the transition between Sb(III) and Sb(V), with Sb pollution in bottom water during winter being of concern.

Antimony and arsenic exhibit contrasting spatial distributions in the sediment and vegetation of a contaminated wetland

Antimony is a priority environmental contaminant that is relatively poorly studied compared to other trace metal(loid)s. In particular, the behaviour of antimony in wetland sediments, where anaerobic conditions often dominate, has received considerably less attention compared to well-drained terrestrial soil environments. Here we report the results of a spatial assessment of antimony in the sediments and vegetation of a freshwater wetland exposed to stibnite tailings for the past forty years. The concentration of antimony in the sediment decreased rapidly with distance from the tailings deposit, from a maximum of ∼22,000 mg kg−1 to ∼1000 mg kg−1 at a distance of ∼150 m. In contrast, arsenic was distributed more evenly across the wetland, indicating that it was more mobile under the prevailing hypoxic/anoxic conditions. Less clear trends were observed in the tissues of wetland plants, with the concentrations of antimony in waterlilies (2.5–195 mg kg−1) showing no clear trends with distance from the tailings deposit, and no correlation with sediment concentrations. Sedges and Melaleuca sp. trees had lower antimony concentrations (<25 mg kg−1 and 5 mg kg−1, respectively) compared to waterlilies, but showed a non-significant trend of higher concentrations closer to the tailings. For all vegetation types sampled, antimony concentrations were consistently lower than arsenic concentrations (Sb:As = 0.27–0.31), despite higher concentrations of antimony in the sediment. Overall, the results of this study highlight clear differences in the behaviour of antimony and arsenic in freshwater wetlands, which should be considered during the management and remediation of such sites.

Assessing the remobilization of Antimony in sediments by DGT: A case study in a tributary of the Three Gorges Reservoir

The Three Gorges Reservoir (TGR) is one of the world's largest man-made hydropower projects, which has posed great challenges to the aquatic environment of the Yangtze River since the impoundment of water. As a non-essential toxic metalloid, information on the bioavailability of Antimony (Sb) in TGR sediments is lacking. Four sediment cores were collected from a tributary and the mainstream in the TGR to investigate the distribution and remobilization of Sb using the diffusive gradients in thin films (DGT) technique. The results showed that the concentrations of Sb obtained by DGT (CDGT-Sb) at all of the sampling stations were low (below 0.30 μg/L), compared to the relatively high Sb concentrations in the sediments. The lateral and vertical distributions of CDGT-Sb revealed different tendencies in overlying water and sediments at all of the sampling sites in the TGR, which may be attributed to anthropogenic impacts, the heterogeneity of sediments and the unevenness of the sediment-water interface (SWI) during the deployment of DGT probes. In addition, CDGT-Sb in the surface sediments were lower than those in the overlying water, and concentration gradients were found near the SWI, demonstrating that Sb has the potential to diffuse from the overlying water into the sediment. In the sediment cores, different peaks were discovered in the DGT probes and the remobilization of Sb simultaneously appeared in the vicinity of −10 cm. Correlation analysis showed that CDGT-Sb had no or negative correlation with CDGT-Fe and CDGT-Mn in all of the DGT probes, suggesting that the release of Sb was unassociated with Fe and Mn in the sediments in the study area.

Determination of antimony in sediments and soils by slurry sampling graphite furnace atomic absorption spectrometry using a permanent chemical modifier

For comparison of action of mixed permanent modifiers Ir/Nb and Ir/W, the influence of the amounts of modifier components was studied and the atomic absorption pyrolysis and atomization curves were determined with different modifiers. The optimum amounts of modifier components were 30 μg Ir and 40 μg of Nb that were deposited onto the L'vov platform in advance to analytical measurements. The long-term performance of the Ir and Nb permanent modifiers was derived from the investigations by scanning electron microscopy and energy dispersive X-ray spectrometry. The soil and sediment slurries were prepared in 4% hydrofluoric acid and 6% suspension of polytetrafluoroethylene in order to remove the high concentration of silica during the pyrolysis step of 900 °C. The calibration was made by using aqueous standards. The analysis of certified reference materials confirmed the accuracy and reliability of the proposed analytical approach. The precision of Sb determination was characterized with less than 6% RSD.

Determination of Antimony in Sediments by Zeeman‐Corrected Electrothermal Atomic Absorption Spectrometry with Ultrasonic Slurry Sampling

AbstractA method was developed for the determination of antimony in slurried sediments (on the basis of samples of three Certified Reference Materials) by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman‐effect background correction. Slurried samples were prepared in 6% nitric acid containing 0.02% of Triton X‐100. A mixed palladium/magnesium chemical matrix modifier, L'vov platform atomization and a temperature‐time program with a relatively short (10 s) sample pyrolysis stage were used.The results of the determinations by this technique are in very close agreement with certified values and the repeatability of this analytical procedure expressed in terms of relative standard deviation was typically better than 9% at the slurry concentration of approx. 90 mg/2 mL. The characteristic mass of Sb (at the spectral line 231.1 nm) was 25.6 pg and the limit of detection (calculated for 100 mg/2 mL slurry) was about 0. 04 μg/g.

水素化物発生原子吸光法による底質中のひ素，セレンおよびアンチモン分析

A hydride generation-atomic absorption method for the precise and sensitive determination of arsenic, selenium and antimony in sediments is described. The environmental certified reference materials sample was digested with HF/HNO3/HCIO4/KMnO4, and the residue was disolved in dilute hydrochloric acid with heating 1 hour on a boiling water bath. For As and Sb, potasium iodide-ascorbic acid were added to prereduction and acidfied sample solutions with hydrochloric acid were lead to automated hydride generator and determined As, Se and Sb by atomic absorption spectrometer individually. Analytical results of As, Se and Sb obtained by proposed method are in good agreement with the certified or reference values for the CRMs included BCSS-1, Pond Sediment, NIST 1646 and SL-1, the relative standard deviations are less than 5%. Determination of analytes could be performed with only one digestion procedure and small modification of pretreatment for these hydrides generation. On the other hand, several acid digestion procedures were examined for routine analysis of environmental samples, the best results which gave high recoveries were obtained by using the procedure with HNO3/HClO4/KMnO4 for As, Se and with hydrochloric acid for Sb. Application of the procedure with HNO3/HClO4/KMnO4 for the determination of Sb resulted in unsatisfactory recoveries, it was suggested that antimony formed insoluble compounds in dilute hydrochloric acid, and sorbed on the residue of sediment. Ratios of analytical results of analytes for 4 CRMs obtained by recommended acid digestion to obtained by HF/HNO3/HClO4/KMnO4 procedure were about 0.70-0.90 for arsenic, larger than 0.90 for selenium and almost 0.87 for antimony respectively. The limits of determination of anlytes are 0.0375 μg·g-1 for 2g of sediment.

Speciation of antimony by atomic absorption spectrometry. Applicability to selective determination of Sb(III) and Sb(V) in liquid samples and of bioavailable antimony in sediments and soil samples

A comparative study was made of several methods to speciale Sb(III) and Sb(V) by AAS: 1) Selective extraction of Sb(III) with lactic acid/malachite green graphite furnace-AAS, 2) Sb(III) and total antimony determination by hydride generation-AAS coupled to flow injection, batch, and continuous flow systems. These methods were applied to determine total antimony and Sb(III) in sea and surface water and total antimony in sediments and in soil. For soils different sample pretreatments were used: HNO3-H2SO4-HC1O4, HF-HNO3-H2SO4-HC1O4, cold aqua regia and slurry formation procedures in water and 4M HC1. In each case the recovery of total antimony and the ability to selective determine Sb(III) were studied. The detection limits obtained were 0.01 ng, 0.07 ng, 2.97 ng and 0.21 ppb for GF-AAS, FIA-HG-AAS, HG (Batch)-AAS, and HG (continuous flow)-AAS, respectively.

The Distribution of Mercury, Arsenic, and Antimony in Sediments of Kagoshima Bay

Abstract Mercury, arsenic, and antimony were determined in marine sediments collected from Kagoshima Bay, and their distribution was investigated. The contents of mercury, arsenic, and antimony in surface sediments were higher than those in the marine sediments of the open ocean. The average contents of mercury, arsenic, and antimony in surface sediments in the northern part of the bay were higher than in the southern part. The high-temperature sediments (about 200 °C) in the vicinity of a sea bottom fumarole, located at a depth of about 200 m in the northern part of the bay, showed abnormal concentrations of mercury, arsenic, and antimony derived from the fumarole gas; the contents of these components decreased sharply with an increase in the distance from the fumarole. A high degree of positive correlation was found among the contents of the three components (mercury, arsenic, and antimony) over the northern part of the bay. In contrast, no such correlation was observed in the southern part of the bay. This is in accord with the fact that volcanic activity is more vigorous in the northern than in the southern part of the bay.

Fixation and mobilization of antimony in sediments

The mobility of sediment antimony (Sb) during sediment-water interactions was studied. Emphasis was placed on the fixation of native and added Sb by sediment, long-term (6 months) releases of Sb and sediment properties that affect the mobilization of Sb. Sequential selective extraction procedures revealed that most native and added sediment Sb was associated with relatively immobile iron (Fe) and aluminum (Al) compounds. In sediments amended with Sb, concentrations of interstitial water and exchangeable phase Sb were also high. Initial and long-term releases of Sb were much higher from Sb-amended sediments than from sediments containing no added Sb, apparently a result of Sb concentrations in more mobile sediment phases. In most sediments, the largest amount of Sb release occurred early in the leaching experiment. These results suggest that Sb release from contaminated sediments is more likely to occur during the first few months of sediment-water interaction. During aerobic leaching, Sb moved into a more unavailable sediment phase, decreasing the potential for further releases. Sediment Fe and CaCO 3 equivalent concentrations were found to affect releases of added Sb. Evolution of volatile Sb compounds was also noted from sediments under anaerobic conditions.