Removal Of Antimony Research Articles

S0-dependent bio-reduction for antimonate detoxification from wastewater by an autotrophic bioreactor with internal recirculation.

Elemental sulfur (S0) autotrophic reduction is a promising approach for antimonate [Sb(V)] removal from water; however, it is hard to achieve effective removal of total antimony (TSb). This study established internal recirculation in an S0 autotrophic bioreactor (SABIR) to enhance TSb removal from Sb(V)-contaminated water. Complete Sb(V) reduction (10mg/L) with bare residual Sb(III) (< 0.26mg/L) was achieved at hydraulic retention time (HRT) = 8h. Shortening HRT adversely affected the removal efficiencies of Sb(V) and TSb; meanwhile, an increased reflux ratio was conducive to Sb(V) and TSb removal at the same HRT. Sulfur disproportionation occurred in the SABIR and was the primary source for SO42- generation and alkalinity consumption. The alkalinity consumption decreased with the shortening HRT and increased with an increased reflux ratio at the same HRT. The generated SO42- was significantly higher (50-100 times) than the theoretical value for Sb(V) reduction. Coefficient of variation (CV), first-order kinetic models, and osmolality analyses showed that internal recirculation did not significantly affect the stability of SABIR but contributed to enhancing TSb removal by increasing mass transfer and reflowing generated sulfide back to the SABIR. SEM-EDS, Raman spectroscopy, XRD and XPS analyses identified that the precipitates in the SABIR were Sb2S3 and Sb-S compounds. In addition, high-throughput sequencing analysis revealed the microbial community structure's temporal and spatial distribution in the SABIR. Dominant genera, including unclassified-Proteobacteria (18.72-38.99%), Thiomonas (0.94-4.87%) and Desulfitobacterium (1.18-2.75%) might be responsible for Sb(V) bio-reduction and removal. This study provides a strategy to remove Sb from water effectively and supports the theoretical basis for the practical application of the SABIR in Sb(V)-contaminated wastewater.

Antimony removal using zero-valent iron-manganese bimetallic nanomaterial: Adsorption behavior and mechanism

Although the effectiveness of zero-valent iron (ZVI) and zero-valent manganese (ZVMn) in heavy metal removal is well-established, their combined synergistic potential for antimony (Sb) remediation from wastewater has remained largely unexplored. Addressing this gap, this study introduced a magnetic zero-valent iron-manganese bimetallic material (ZVIM), synthesized via the borohydride reduction method, to investigate its capabilities and underlying mechanisms for Sb reduction and adsorption. The ZVIM, characterized by a high specific surface area of 220 m²/g, exhibited a high adsorption capacity (614.6 mg/g for Sb(III) and 241.7 mg/g for Sb(V)), facilitating over 96.7 % removal for both Sb(III) and Sb(V). The adsorption conformed to the pseudo-second-order kinetic model, and the isotherm data aligned with the Freundlich model, indicative of a heterogeneous adsorption process. The removal of Sb(III) predominantly occurred via surface complexation and electrostatic adsorption to the positively charged ZVIM surface, accompanied by a partial oxidation of Sb(III) to Sb(V). In contrast, the elimination of Sb(V) was primarily facilitated through surface complexation mechanism, encompassing both reduction and electrostatic adsorption. The outcomes of this study shed light on the intricate interactions between Sb species and the ZVIM, revealing the material as a promising candidate for the efficacious removal of Sb from wastewater.

Analysis of Antimony Removal with Modified Activated Carbon Using Response Surface Methodology

Analysis of Antimony Removal with Modified Activated Carbon Using Response Surface Methodology

Metal(loid)s Removal Response to the Seasonal Freeze–Thaw Cycle in Semi-passive Pilot Scale Bioreactors

There is an increasing demand for cost-effective semi-passive water treatment that can withstand challenging climatic conditions and effectively and sustainably manage mine-impacted water in (sub)arctic regions. This study investigated the ability of four pilot-scale bioreactors inoculated with locally sourced bacteria and affected by a freeze–thaw cycle to remove selenium and antimony. The bioreactors were operated at a Canadian (sub)arctic mine for a year. Two duplicate bioreactors were installed in a heated shed that was maintained at 5 °C over the winter, while two other duplicates were installed outdoors and left to freeze. The removal rate of selenium and antimony was monitored weekly, while a genomic characterization of the microbial populations in the bioreactors was performed monthly. The overall percentage of selenium and antimony removal was similar in the outside (10–93% Se, 20–96% Sb) and inside (35–94% Se, 10–95% Sb) bioreactors, apart from the spring thawing period when removal in the outdoor bioreactors was slightly lower for Se. The dominant taxonomic groups of microbial populations in all bioreactors were Bacteroidota, Firmicutes, Desulfobacterota and Proteobacteria. The microbial population composition was consistent and re-established quickly after spring thaw in the outside bioreactors. This demonstrated that the removal capacity of bioreactors inoculated with locally sourced bacteria was mostly unaffected by a freeze–thaw cycle, highlighting the strength of using local resources to design bioreactors in extreme climatic conditions.

Biochar-Sulfate Reducing Bacteria synergy: A green approach for antimony removal and recovery from high-concentrated waters

Environments with elevated antimony (Sb) levels often result from industrial and mining activities, causing harm to ecosystems due to the inherent toxicity. Traditional treatments aim to eliminate or decrease Sb toxicity, yet they often result in the generation of secondary pollution. This study explores a novel approach for enhancing biological sulfate-reduction by biochar addition to cope with high Sb concentrations. Moreover, this research postulates sulfate-reduction bioprocess as a feasible alternative to obtain valuable antimony sulfide. The findings indicate that sulfate reduction effectively removes antimony, particularly at high concentrations, using a non-specialized inoculum. Biochar plays a pivotal role in enhancing sulfate-reduction rates, reducing lag-phase periods, and enriching the microorganisms responsible for sulfate reduction.Interestingly, lower concentrations of Sb(III) (5–40 mg/L) and Sb(V) (5–100 mg/L) exhibited a lower removal percentage compared to higher concentrations of Sb(III) (80–500 mg/L) and Sb(V) (200–1000 mg/L). This phenomenon was attributed to the excess sulfide hindering the equilibrium of the first-order reaction at lower concentrations, while at higher concentrations, the reaction proceeded more rapidly. A combination of biochemical and physicochemical reactions facilitated the removal of >95 % Sb(III) and >97 % Sb(V) using biochar.Furthermore, various taxa displayed a significant logarithmic rate of change in their abundance, influenced by the application of biochar or the introduction of distinct antimony species. The biogenic sulfide generated through the sulfate reduction process reacted with the Sb species, resulting in the precipitation of stibnite (Sb2S3), Na3SbS3, and Na3SbS4. These precipitates are considered crucial precursors in electronic applications.In conclusion, this study constitutes a pioneering exploration of elevated antimony (Sb) concentrations under sulfate-reducing conditions, significantly contributing to an advancement of knowledge in the application of biological processes.

Selective recovery of antimony from Sb-bearing copper concentrates by integration of alkaline sulphide leaching solutions and microwave-assisted heating: A new sustainable processing route

The technical feasibility of leaching antimony from an antimony-bearing copper sulphide concentrate, using alkaline sulphide solutions and microwave-assisted and non-assisted heating technology, is investigated at a laboratory scale. The leaching test examines the influence of selective leaching reagent (Na2S and NaOH) concentrations, solid/liquid ratio, and temperature. The results indicate that antimony dissolution is highly selective (e.g. only Sb and As are leached), depending on the concentrations of leaching reagents and the leaching temperature. The influence of temperature on the mineral's dissolution, in the range 25–140 °C, is analysed from a thermochemical point of view using equilibrium databases. Under the optimal conditions: leaching agent: 250 g/L Na2S, 60 g/L NaOH, 2 h, 140 °C, with microwave assisted, the leaching efficiency of Sb reached 95.7 %. The antimony content in the copper concentrate is successfully reduced from 1.1 wt% to <0.2 wt% Sb, making it suitable for copper concentrate metallurgical processing. The study demonstrates that increasing temperature and NaOH/Na2S concentrations collectively enhance leaching efficiency, with a statistical significance, reducing both leaching time and the required temperature, compared to non-microwave-assisted leaching. Furthermore, it is established that excess free hydrogen sulphide ions ensure the efficient dissolution of the main impurities associated with penalties, such as antimony and arsenic, with limited copper and iron dissolution from the copper concentrate, predominantly chalcopyrite. Finally, an integrated hydrometallurgical process flowsheet for antimony removal and recovery from a sulphide copper concentrate is proposed.

Remediation on antimony-contaminated soil from mine area using zero-valent-iron doped biochar and their effect on the bioavailability of antimony

Due to the bioavailability and movement of antimony in trophic web, the overexploitation of antimony mine resulted in antimony contamination that harmed the ecology nearby, raising concerns for public health. Whereas, most researches focused on the removal of antimony in the aqueous instead of the immobilization of antimony in the soil. Herein, the immobilized performance of biochar (BC) loaded with nano zero-valent iron (nZVI-BC) on antimony in the soil near the smelting area was researched through pot experiments for the first time, and its stabilization mechanism on antimony was investigated by valent state variation of antimony. The results demonstrated that BC restricted the cation exchange capacity and catalase activity in the soil, while nZVI-BC had a favorable and negative impact on two variables, respectively. The nZVI-BC showed more stable immobilization capacity on antimony over time than BC, whose exchangeable speciation only marginally rose (2%–6%), although the exchangeable speciation of antimony fell both from 15% to 2% after adding the BC and nZVI-BC, The electron attraction force between nZVI-BC and antimony was also intensified owing to the oxidation-reduction process, which was considered as the stabilizing principle of nZVI-BC on antimony in soil. Furthermore, the decreased bioaccumulation factor for the perennial ryegrass (0.46–0.21) and Galinsoga parviflora Cav. (0.26–0.17) stated that the BC effectively mitigated the bioaccumulation risk of antimony.

Study on micron Zero-valent Iron (mZVI) material for adsorption and removal of antimony (V)

In this study, micron Zero-valent Iron (mZVI), an affordable and well-dispersible reducing agent, was investigated for its potential application in removing Sb(V) from wastewater. Since Sb(V) primarily exists as Sb(OH)6- in aqueous solutions, the lower the pH, the more effective mZVI is in removing Sb(V). At a pH level of 3, mZVI (1.0 g/L) was able to remove more than 99 % of Sb(V) (20 mg/L) from the wastewater. The study also compared the influence of cations and anions on mZVI and found that anions had a greater impact on the material's performance. The paper further examined the impact of different heavy metal ions on mZVI and determined that the adsorption capacity of mZVI towards these ions follows the order of their reducing ability. Summarizing the removal mechanism of Sb(V) by mZVI, it was found that both adsorption and redox reactions played crucial roles and Sb(V) is ultimately removed from water through coprecipitation by combining with Fe-O on the mZVI surface. Theoretically, the maximum adsorption capacity of the mZVI material used in this study could reach 21.60 mg/g for Sb(V). This makes mZVI a promising environmental adsorption material and a potential solution for treating water pollution caused by antimony mining.

The adsorption behavior and mechanism of antimony in water by jarosite ball milling mixed with nano zero-valent iron

In this study, the functional material (BMJR-nZVI) of jarosite (JR) mixed with nano-zero-valent iron (nZVI) was prepared by mixed ball milling. The surface morphology, elemental composition, specific surface area and functional groups of adsorbed materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier infrared light (FTIR), X-ray photoelectron spectroscopy (XPS), specific surface area analyzer (BET) and vibrating sample magnetometer (VSM). The influence of different mixing ratio, ball milling time and other process conditions on the antimony removal performance of BMJR-nZVI was studied, and the treatment conditions were optimized. Effects of combination method, milling ratio and milling time on the adsorption properties of BMJR-nZVI were investigated by single factor test. The results showed that the adsorbent had the best adsorption properties for Sb under the conditions of JR: nZVI 2:1 and milling time of 2 h. In antimony containing solution with pH 6 and initial concentration of 20 mg·L−1, the removal rate of Sb(III) and Sb(V) can reach up to 60.92 % and 99.82 % respectively, and BMJR-nZVI material is magnetic and can be recycled well. Main mechanism of adsorption, complexation and co-precipitation of antimony by BMJR-nZVI was confirmed.

Recovery of Sb(Ⅲ) from Aqueous Solution as Cubic Sb2O3 by Fluidized-Bed Granulation Process

In order to recover the antimony from wastewater, a custom-designed fluidized-bed reactor (FBR) was employed to treat antimony-containing wastewater. By single-factor experiments, the effects of the solution pH, the molar ratio of [TA]/[Sb3+], the seed size and dosage, the up-flow velocity (U), and the hydraulic retention time (HRT) on antimony recovery were investigated based on the antimony removal and granulation efficiency. The optimum conditions for antimony recovery were obtained at pH 9.0, the molar ratio of [TA]/[Sb3+] of 2, 6 g/L of 13–38 μm Sb2O3 as the fluidized seed, and the U and HRT of 42 m/h and 40 min, respectively; the antimony removal and granulation efficiency reached 95% and 91%, respectively. The granular products were analyzed by an X-ray polycrystalline diffractometer (XRD) and scanning electron microscopy (SEM) as cubic Sb2O3, widely used in various industries. The fluidized-bed reactor was operated continuously for 7 days, during which the antimony removal and granulation efficiency were stable at 96% and 93%, respectively. This study demonstrated the feasibility of the fluidized-bed granulation process for the recovery of antimony from wastewater. It provides a novel approach for retrieving and managing antimony-containing wastewater.

High capacity adsorption of antimony by hollow Co-MnO2 and its consequential utilization in SbO2--based aqueous batteries

Toxic metal pollution is one of the environmental problems that seriously affect water resources and ecosystems. Antimony, recognized for its teratogenic and carcinogenic properties, poses significant health risks due to its widespread presence in natural water sources. In this study, cobalt-doped manganese oxide bimetallic composites were designed as an efficient adsorbent for the antimony removal from water. The adsorbent exhibits robust performance over a range of pH values, achieves a significant adsorption capacity of 591.1 mg/g, and exhibits adsorption equilibrium within 25 min. The effectiveness of the adsorption is attributed to the interaction between metal-O bonds and antimony, as well as the hydrogen bonding. In line with the concept of sustainable development, waste adsorbents are used as negative electrodes for SbO2--based aqueous alkaline batteries. It exhibits a high reversible specific capacity of 122.8 mAh·g−1. This research not only sheds light on innovative approaches to antimony removal but also opens up avenues for the sustainable reuse of waste materials, in line with the principles of sustainable development.

New insights on antimony removal and recovery from water and wastewater using iron-coated cork granulates: Desorption on batch and fixed-bed column systems

This work investigated Sb adsorption–desorption using iron-coated cork granulates (ICG) in both batch and continuous modes to evaluate the materiaĺs adsorption and regeneration performance, as well as the possibility of antimony recovery. A fixed-bed column filled with ICG, demonstrated maximum adsorption capacities of 13 ± 2 mg g−1 and 10 ± 1 mg g−1 for Sb(III) and Sb(V), respectively, at pH 3. ICG was able to remove Sb within the WHO guideline of 20 μg/L at pH 6. Among the different classes of eluents tested for Sb(V) desorption, the acids achieved the highest desorption rates − 81 ± 9 % and 66 ± 8 % for HCl 1 M and ascorbic acid 0.1 M, respectively. The desorption kinetics showed that HCl 1 M reached equilibrium in 4 h, but ascorbic acid 0.1 M took 16 h. This work presents an ecological emerging solution for antimony removal and recovery from water and wastewater.

Facile synthesis of Bi3O(OH)(AsO4)2 and simultaneous photocatalytic oxidation and adsorption of Sb(III) from wastewater

Antimony (Sb) decontamination in water is necessary owing to the worsening pollution which seriously threatens human life safety. Designing bismuth-based photocatalysts with hydroxyls have attracted growing interest because of the broad bandgap and enhanced separation efficiency of photogenerated electron/hole pairs. Until now, the available photocatalysis information regarding bismuth-based photocatalysts with hydroxyls has remained scarce and the contemporary report has been largely limited to Bi3O(OH)(PO4)2 (BOHP). Herein, Bi3O(OH)(AsO4)2 (BOHAs), a novel ultraviolet photocatalyst, was fabricated via the co-precipitation method for the first time, and developed to simultaneous photocatalytic oxidation and adsorption of Sb(III). The rate constant of Sb(III) removal by the BOHAs was 32.4, 3.0, and 4.3 times higher than those of BiAsO4, BOHP, and TiO2, respectively, indicating that the introduction of hydroxyls could increase the removal of Sb(III). Additionally, the crucial operational parameters affecting the adsorption performance (catalyst dosage, concentration, pH, and common anions) were investigated. The BOHAs maintained 85% antimony decontamination of the initial yield after five successive cycles of photocatalysis. The Sb(III) removal involved photocatalytic oxidation of adsorbed Sb(III) and subsequent adsorption of the yielded Sb(V). With the acquired knowledge, we successfully applied the photocatalyst for antimony removal from industrial wastewater. In addition, BOHAs could also be powerful photocatalysts in the photodegradation of organic pollutants studies of which are ongoing. It reveals an effective strategy for synthesizing bismuth-based photocatalysts with hydroxyls and enhancing pollutants’ decontamination.

High-performance thin film composite forward osmosis membrane for efficient rejection of antimony and phenol from wastewater: Characterization, performance, and MD-DFT simulation

The effective removal of heavy metals and phenolic pollutants from aqueous solutions has received widespread attention in the field of wastewater treatment. In this work, a novel PAN/CNTs/UiO-66-NH2 modified forward osmosis (FO) membrane was prepared for efficient removal of antimony (Sb) and phenol from wastewater. The membrane was synthesized using a facile and cost-effective method. The PAN/CNTs substrate membrane was prepared using electrospinning technology, and UiO-66-NH2 MOF particles were loaded onto the surface of the active layer during the interfacial polymerization (IP) process. The presence of CNTs in the spinning solution regulated the pore structure and properties of nanofibers. Characterization of the membrane confirmed its unique structure and enhanced properties. When the CNTs addition was 0.01 g, and UiO-66-NH2 addition was 0.05 wt%, the FO membrane exhibited the optimal operational performance. In the AL-FS mode, the water flux, reverse salt flux (RSF), and Js/Jw ratio were 14.68 LMH, 0.17 gMH, and 0.01 g/L, respectively. As a comparison, the water flux, RSF, and Js/Jw ratio were 21.19 LMH, 0.65 gMH, and 0.032 g/L in the AL-DS mode, respectively. Simultaneously, efficient removal of antimony and phenol was achieved in both modes, with antimony removal efficiencies of 99.26 % and 97.98 %, and phenol removal efficiencies of 96.61 % and 93.18 %, respectively. The modified membrane exhibited excellent performance in rejecting Sb and phenol. Molecular dynamics simulations and density functional theory calculations provide theoretical support for the excellent performance of membranes. The membrane demonstrated a high water flux, making it promising for practical applications. Additionally, it exhibited remarkably low reverse salt flux, highlighting its suitability for desalination processes. The exceptional removal efficiency of Sb and phenol, coupled with the membrane's impressive hydraulic performance, makes it a promising candidate for the treatment of industrial effluents containing these challenging contaminants. The results presented in this study underscore the potential of PAN/CNTs/UiO-66-NH2 FO membranes as an advanced solution for addressing water pollution challenges.

Selective Removal of Arsenic and Antimony from Pb-Ag Sulfide Concentrates by Alkaline Leaching: Thermodynamic and Kinetic Studies

Arsenic and antimony are impurities that reduce the economic value of concentrates due to the environmental problems they cause. The removal of these impurities by hydrometallurgical means has been highly studied for sulfide copper concentrates using different leaching agents in an alkaline medium (NaClO, H2O2, NaOH, Na2S, NaHS, and S). For a lead–silver concentrate consisting of galena, sphalerite, and pyrite, it was possible to selectively reduce the arsenic content from 1.10% to 0.55% and antimony from 2.41 to 1.04% through the digestion-leaching technique that uses elemental sulfur as a leaching agent in alkaline medium. The adequate powdered sulfur and sodium hydroxide dosage were 336 and 342 kg/t, respectively. The process was carried out at 120 °C with a liquid/solid ratio of 2 in digestion and 5.67 in leaching; the appropriate digestion and leaching time were 20 and 30 min, respectively. The thermodynamics and kinetics of this process turned out to be very complex due to the great variety of simultaneous leaching and precipitation reactions. The digestion process exhibited a mixed kinetic control, where diffusion through the boundary layer and the chemical reaction were the controlling steps with an activation energy of 11.05 kcal/mol.

Enhanced Removal of Antimony and Aniline from Wastewater by Combining Electrocoagulation with Peroxymonosulfate

Enhanced Removal of Antimony and Aniline from Wastewater by Combining Electrocoagulation with Peroxymonosulfate

Removal of Antimony from Industrial Crude Arsenic by Vacuum Sublimation: Combination of Thermodynamics and Ab Initio Molecular Dynamics

Thermodynamic theory was employed in this study to investigate the feasibility of separating antimony (Sb) from crude arsenic (As) using vacuum sublimation. Ab initio molecular dynamics simulations are used to calculate the structure, stability, and diffusion properties of AsmSbn (m + n ≤ 6) clusters. As4, As3Sb, As2Sb2, and AsSb3 are the possible clusters in this thermodynamic calculation, and the molecular dynamics results confirmed their structural stability and stabilization in the gas phase. As4 had the largest diffusion coefficients, which is the reason it separates from the Sb-containing clusters (As3Sb, As2Sb2, and AsSb3) during gas-phase diffusion and condensation processes. The experimental results show that As vapor was transformed from crystalline to amorphous with increasing subcooling, and the Sb-containing clusters that enter the gas phase were mainly condensed and deposited at the proximal end of the heating zone. Not considering the volatilization rate, the removal rate of Sb in products can reach 99.35% by increasing the condensation disk and expanding the condensation zone; thus, experiments confirmed that industrial crude arsenic can realize deep Sb removal after vacuum sublimation.

Facile Preparation of Magnetic Chitosan Carbon Based on Recycling of Iron Sludge for Sb(III) Removal

In this study, following the concept of “treating waste with waste”, magnetic chitosan carbon (MCC) was developed through the pyrolysis of chitosan/iron sludge (CHS) beads created using an embedding method in a closed environment for antimony removal. The results indicate MCC has a good magnetic recovery rate and that its magnetic saturation strength can reach 33.243 emu/g. The iron proportion and acid resistance of MCC were all better than those of CHS, and at 25 °C, its adsorption saturation capacity improved from 24.956 mg/g to 38.234 mg/g. MCC has a quick adsorption equilibrium time, and in about 20 min, 90% of the final equilibrium capacity can be achieved. The primary mechanism of Sb adsorption by MCC is the formation of an inner sphere complex between Fe-O and Sb, while surface complexation, hydrogen bonding, and interaction also play a function. Thus, MCC, a lower-cost and greener adsorbent for Sb removal, has been made using iron sludge. This enabled it to utilize iron sludge as a resource and served as a reference for the sustainable management of water treatment residuals.

Mushroom residue derived magnetic hydrochar for antimony removal from wastewater: Mechanisms insights and practicality assessment

The magnetic mushroom residue hydrochar (MMRH) was synthesized using mushroom waste and K2FeO4, and then applied for antimony (Sb) removal from wastewater. The maximum adsorption capacity of Sb(III) and Sb(V) by MMRH reached 636.9 and 814.3 mg/g, respectively. According to characterizations, the existence of K+ in MMRH significantly increased the ion exchange of Sb species. Further, the Fenton-like reactions could generate additional •OH species to effectively oxidize Sb(III) into Sb(V), while other mechanisms including complexation, co-precipitation, and physical adsorption were also comprehensively investigated. The practicality of this MMRH was also assessed by recycling and column experiments. This study is expected to offer novel perspectives on mushroom residue reutilization and Sb-polluted wastewater purification for a greener environment.

Antimony Removal in a Lab-scale Anaerobic Upflow Fluidized Bed Reactor Packed with PVA Gel-beads Inoculated with a &lt;i&gt;Desulfovibrio&lt;/i&gt; sp. Strain

Antimony Removal in a Lab-scale Anaerobic Upflow Fluidized Bed Reactor Packed with PVA Gel-beads Inoculated with a &lt;i&gt;Desulfovibrio&lt;/i&gt; sp. Strain