Arsenic Oxide Research Articles

Study on the occurrence characteristics of arsenic in copper matte

The occurrence characteristics of arsenic in matte phase are unclear, which leads to the current treatment technology not being able to remove arsenic from matte phase significantly, thus causing a large amount of arsenic to affect smelting links such as copper converting and electrolytic refining. This paper uses instrumental analysis such as XRD, SEM-EDS, MLA and chemical analysis methods such as chemical phase extraction to comprehensively analyze the occurrence characteristics of arsenic in matte phase. The results show that the occurrence states of arsenic in matte are mainly arsenic sulfide, arsenic oxide, arsenate and residual arsenic. Most of the arsenic is in residual state in matte; arsenic in matte is extremely stable and difficult to exchange with the outside world; in high-grade matte, the arsenic content is relatively high. The main occurrence state of arsenic is copper-based complex alloy compounds, in which the arsenic content is about 1-10%. Since the metal bond between Cu-As is extremely stable, it is difficult to separate arsenic from it, which is also the key to the difficulty in completely removing arsenic from matte.

Silicate impedes arsenic release and oxidation from ferrihydrite

Silicate fertilization is a common farming practice and an effective method to mitigate arsenic (As) pollution in paddy. Investigating the interaction between silicate and ferrihydrite on As retention is key to comprehensively understand the mechanism of As sequestration by silicate fertilization. Our results indicated that the transformation of ferrihydrite into goethite and hematite was inversely proportional to Si/Fe ratios. The added silicate impeded the decrease of solution pH from neutral to acidity, and imposed strong inhibitory effect on goethite formation. The aqueous As in silicate-free system was 3.43 times higher than that with Si/Fe ratio at 0.33, but similar results were not observed in those with high-level As pollution due to the inhibitory effect of As on ferrihydrite transformation. Solid characterization showed that silicate was monomerically adsorbed to ferrihydrite through Si-O-Fe bond, which impeded the reductive dissolution, Fe atom exchange, internal atomic rearrangement and dehydration of ferrihydrite. As(III) oxidation weakened in silicate-coprecipitated ferrihydrite due to the lack of Fe(II) catalysis stem from ferrihydrite dissolution. This work demonstrated that As release could be effectively impeded through the inhibitory effect of silicate on ferrihydrite transformation, thereby providing new insights into the understanding of As accumulation reduction in rice by silicate fertilization.

Satellite dish-like nanocomposite as a breakthrough in single photon detection for highly developed optoelectronic applications

A nanocomposite with a unique satellite dish-like structure, termed arsenic (III) oxide iodide (AsO2I)/polypyrrole (Ppy) intercalated with iodide ions (AsO2I/Ppy-I), has been meticulously developed via a two-step process. It features natural satellite dish-like nanostructures, potentially serving as nanoresonators for efficient single photon absorption. With a bandgap of 2.8 eV, the AsO2I/Ppy-I nanocomposite efficiently absorbs photons in the UV and visible light regions, making it suitable for single photon detection. Impressive performance is seen in photocurrent sensitivity measurements, recording values of 0.017 mA.cm−2 under white light and 0.009 mA.cm−2 under monochromatic light at 340 nm. Additionally, it exhibits high responsivity and detectivity, with peak values at wavelengths of 340 nm and 440 nm associated with the diameter of the Satellite dish nanostructure. Cost-effectiveness and simple synthesis methods make it attractive for industrial applications, while its unique structural characteristics and enhanced optical properties position it as a valuable asset in optoelectronic technologies. It holds promise as a leading material in advanced quantum technology, marking a significant leap forward in optoelectronic technologies, with potential applications in quantum cryptography, communication, and computing.

Unravelling the mechanism of arsenic resistance and bioremediation in Stenotrophomonas maltophilia: A molecular approach

The mechanism of arsenic resistance in bacteria is under studied and still lacks a clear understanding despite of wide research work. The advanced technologies can help in analysing the arsenic bioremediating bacteria at a molecular level. With this line of idea, highly efficient arsenic bioremediating S. maltophilia was subjected to extensive analysis to understand the mechanism of arsenic resistance and bioremediation. The cell surface analysis revealed that S. maltophilia induces only slight changes in cell surface in the presence of arsenic. Whereas, TEM analysis has indicated the bioaccumulation of arsenic in S. maltophilia. Also, arsenic was found to generate ROS in a concentration dependant manner, and in response, S. maltophilia activated SOD, catalase, thioredoxin reductase etc. to manage oxidative stress which is very much crucial in managing arsenic toxicity. S. maltophilia was found to possess genes such as arsC, aoxB, aoxC and aioA. These genes are involved in arsenic reduction and oxidation. Transcriptomics and proteomics analysis have shown that S. maltophilia detoxifies arsenic by upregulating ars operon, arsH, BetB etc. which are responsible for arsenic reduction, efflux methylation, oxidation etc. A detailed molecular mechanism of arsenic bioremediation in S. maltophilia was put forth.

Synergistic ultra-high adsorption and oxidation of arsenic in groundwater by iron-modified biochar: Mechanisms and potential application

This study explores the potential of low-cost biochar modified with ferrihydrite and goethite for the remediation of heavily As-polluted groundwater. Combining batch experiments and synchrotron radiation-based characterization, we investigated the mechanisms of As(III) adsorption and oxidation. The modified biochars exhibited significant adsorption capacities, achieving fitted qmax of 45.7 ± 3.9 mg/g for ferrihydrite-modified biochar (FhGM) and 20.2 ± 1.5 mg/g for goethite-modified biochar (GtGM) at a dosage of 1.0 g/L and an initial concentration of 10 mg/L As(III) over 24 h. Biochar facilitated approximately 30 % As(V) generation from As(III) due to enhanced electron transfer. Moreover, over 90 % of As(III) was oxidized to As(V) following the addition of H2O2, with scanning transmission X-ray microscopy revealing the distribution of As(III), and As(V) on the solid phase. In the GtGM-H2O2 system, reactive oxidation species, primarily O2•–, served as the main oxidant. In the FhGM-H2O2 system, Fe(IV) likely acted as the primary oxidizing agent. Column experiments with 0.64 g of FhGM demonstrated that, when treating 50 mg/L As-contaminated groundwater, the effluent total As concentration remained below the maximum allowable limit of 10 μg/L after 21 h. Furthermore, in the presence of H2O2, the system managed to treat 200 mg/L As-contaminated groundwater, and the effluent total As concentration exceeded 10 μg/L after 11 h. This study provides valuable insights and practical results for the remediation of high-concentration arsenic-contaminated groundwater, highlighting the effectiveness of iron-modified biochar in this application.

STUDY OF THE BEHAVIOR OF ARSENIC IN COPPER ELECTROLYTE

Abstract. In industrial wastewater, arsenic is most often present in the trivalent state. An analysis of existing purification methods shows that in all cases, with a few exceptions, the most complete removal of arsenic is observed from solutions in which it is in the pentavalent state. This is explained by the significantly lower solubility of arsenates of heavy and alkaline earth metals compared to the corresponding arsenites. The chemical oxidation of As(III) in the following systems was studied: As(III)-H2SO4-H2O, As(III)-MeSO4-H2O, As(III)–H2SO4–MeSO4–H2O (where Me is Cu, Ni, Co, Mn, Zn). The influence of temperature, the amount of transition metal ions, the duration of the experiment, and the concentration of sulfuric acid on the degree of transition of As(III) to As(V) was studied. The effect of catalytic oxidation of As(III) in sulfuric acid solutions was discovered. The maximum degree of oxidation of trivalent arsenic (55-60%) is observed when transition metal salts are introduced into an arsenic solution in the presence of a platinum plate. It has been established that the nature of the studied transition metal salts (Cu2+, Ni2+, Co2+, Mn2+, Zn2+), process duration and temperature do not have a significant effect on the degree of As(III) conversion. The results obtained largely explain the predominance of pentavalent forms of arsenic in production solutions of non-ferrous metallurgy. Key words: copper electrolyte, arsenic, transition metals, catalytic role, instant oxidation effect, activated oxygen.

Effect of arsenic green synthesis nanoparticles on multi-drug resistant Acinetobacter baumannii

Multidrug-resistant strains of Acinetobacter baumannii are pathogenic agents of hospital infections, especially in the intensive care unit (ICU). The purpose of this study is to investigate the antibacterial effects and biosynthesis of arsenic nanoparticles (ARn) using pink rose petals on multi-drug resistant strains of A. baumannii. In this study, plant bioactive molecules present in rose petals are responsible for the synthesis of ARn. The characteristics of ARn were determined through FTIR, EDX, DLS, SEM, UV-Vis, and XRD techniques. In addition, the antibacterial activity of biosynthesized ARn was investigated against multi-drug resistant A. baumannii. The results of SEM revealed that the ARn were spherical with an average diameter of 75.71 nm. The results of XRD confirmed the crystal structure of arsenic oxide phase. The results of antibacterial effects exhibited that the lowest MIC of ARn was 800 μg/ml on the standard strain of A. baumannii and 800 μg/ml against clinical strains of multi-drug-resistant A. baumannii. The results of this study provided an new green synthesis method for ARn, which have a high potential on multi-drug-resistant A. baumannii. This study has the potential to pave the way for further research and developments in this field.

Local edge positioning effect modified carbon nitride for enhancing photocatalytic oxidation of trivalent arsenic

The highly symmetrical structure of heptazine in C3N4 often results in charge localization effects, which hinder the migration of carriers and the formation of active sites. In this study, well-designed C3N4 materials were prepared with carboxylic acid edge sites (ECCN) through a simple polycondensation method. DFT calculations and experimental results demonstrate that the presence of edge COOH units significantly disrupts carrier delocalization on the C3N4 framework, leading to an enhancement of material polarization and inherent electric field. This enhancement facilitates charge transfer and exciton dissociation. Moreover, it exerts a substantial impact on the surface characteristics of ECCN, promoting electron exchange and molecular polarization for As(III). Consequently, it improves capabilities for oxidizing trivalent arsenic by 4 times compared to pure C3N4. Our research represents significant progress in photocatalytic degradation of harmful compounds and provides enhanced understanding regarding control over carrier dynamics and surface reactivity.

Efficient removal and recovery of lead from high arsenic antimony oxide powder

The existence of Pb in crude antimony oxide powder(CAOP) hinders the further smelting and recovery of Sb and leads to some environmental problems. Therefore, the selective removal of Pb from CAOP is important for the production of high-purity antimony products. In this work, Pb in CAOP is removed by HNO3 leaching, achieving purification of CAOP. Then H2SO4 is used to recover Pb from the HNO3 leaching solution. The Pb leaching efficiency reaches 98.9 %, resulting in a decrease in the Pb content from 4.56 % to 0.20 % in CAOP. The Sb leaching efficiency is controlled at around 5.0 %. These confirm HNO3 has good selectivity. The HNO3 disrupts the molecular structure of the raw materials during the leaching, resulting in the conversion of Sb2O3 and As2O3 into insoluble AsSbO4. By adding H2SO4 to the leaching solution, the Pb precipitation efficiency reaches 93.6 %. After Pb removal, the leaching solution can be re-used for the leaching of Pb, while the residue can be directly returned to the pyrometallurgical system. The reaction mechanism and a novel approach for removing Pb from CAOP are proposed, which have the advantages of high selectivity, effective Pb separation, and recoverable HNO3.

Exploring the efficient catalytic decomposition behavior of AsH3 over HZSM-5 molecular sieve based on in situ DRIFTS characterization

Existing processes for transforming arsine (AsH3) into toxic arsenic oxides (AsxOy) through catalytic oxidation do not meet economic requirements. In contrast, the catalytic decomposition method stands out due to its ability to both remove AsH3 and obtain elemental arsenic (As0) as a valuable product. A series of blank molecular sieves (HZSM-5, 13X, MCM-41, and TS-1) was applied to the catalytic decomposition performance of AsH3. At a catalytic decomposition temperature of 100 ℃, the HZSM-5 zeolite exhibited exceptional performance, achieving a D90% value (the duration for which the AsH3 removal efficiency remained above 90 %) exceeding 40 h. Moreover, up to 83.1 % of the product was As0. Comprehensive characterization revealed that the surface of the HZSM-5 zeolite contained a large number of strong acid sites, which played a key role in As0 generation. In situ diffuse reflectance infrared spectroscopy further revealed the activation behavior of O2 at the Brønsted acid sites on HZSM-5. To assess its suitability in industrial applications, the AsH3 removal performance of the HZSM-5 molecular sieve was investigated in the presence of actual gas components (CO, H2S, PH3). This study provides new ideas for the effective catalytic decomposition of AsH3 and the recovery of valuable products in industry.

The promotional role of peroxydisulfate in Arsenic(III) oxidation by Fe(III)/Sulfite: Boosting and regulating the generation of radical and non-radical species

The Fe(III)-activated sulfite (S(IV)) process to yield powerful SO4•−/HO• radicals is increasingly recognized as an appealing advanced oxidation process (AOP). However, its application is constrained by its heavy reliance on dissolved oxygen and the low selectivity of these short-lived radicals. In this work, peroxydisulfate (PDS) was found to indeed amplify the capacity of the Fe(III)/S(IV) system for arsenite (As(III)) oxidation, with increasing the oxidation efficiency and rate constant from 47 % to 95 % and 0.165 min−1 to 0.455 min−1, respectively. The mechanistic study revealed that the predominant reactive species were identified as both radicals (SO4•−/HO•) and non-radical (Fe(IV)O2+ instead of 1O2), with HO• primarily originating from Fe(IV)O2+. Herein, PDS not only acted as an electron acceptor to react with the in-situ formed Fe(II), thus accelerating the Fe(II) ↔ Fe(III) cycle and producing Fe(IV)O2+, but also functioned as a substitute for dissolved oxygen to facilitate SO4•− generation even under anaerobic conditions. Moreover, the generation efficiency and distribution of these oxidizing reactive species were significantly influenced by adjusting experimental parameters (i.e., reagents dosage and solution pH). Overall, this work unveiled an enticing strategy to fine-tune the oxidative prowess and precision of the Fe(III)/S(IV)/PDS system for oxidizing specific contaminants by orchestrating the relative distribution of radicals (SO4•−/HO•) and non-radical (Fe(IV)O2+).

Evaluation of interaction among arsenic and Brevibacterium sp. strain CS2 and its proteins profiling

In this study, Brevibacterium sp. strain CS2 was used to evaluate the mechanisms of arsenic interaction with the bacterium and its enzymatic and protein profiling under arsenic stress. The bacterium was capable to resist the arsenate 280 mM and arsenite 40 mM as per MIC. The whole genome, available on NCBI, was analyzed for genes associated with arsenic, which confirmed the genes for both arsenic oxidation (aioB) and arsenic reduction arsR, arsC, ACR3, and arsB. The sharpening and shifting of FTIR spectra in the ranges of 3278–2851 cm−1 are due to hydroxyl and amide stretching. SEM analysis showed no significant changes in morphology in arsenic stress while EDX analysis proved the arsenite interaction by showing arsenic peaks in the graph. Both glutathione and non-protein thiol showed different responses in the absence and presence of arsenic stress. Protein bands such as 25, 30, 32, 37, 42, 48, and 100 kDa were expressed more in arsenic-treated samples as compared to the control one. The presence of arsenic oxidizing genes, the ability to resist arsenic, and the varied response of enzymes and proteins in arsenic stress make the bacterium a suitable agent for arsenic eradication from contaminated sites.

Advancing nanoarchitectures of 2D WO3/MXene photoanode for enhanced photoelectrocatalytic oxidation of phenol and arsenic in synthetic wastewater

The photoelectrocatalytic advanced oxidation process (PEAOP) necessitates high-performing and stable photoanodes for the effective oxidation of complex pollutants in industrial wastewater. This study presents the construction of 2D WO3/MXene heteronanostructures for the development of efficient and stable photoanode. The WO3/MXene heterostructure features well-ordered WO3 photoactive sites anchored on micron-sized MXene sheets, providing an increased visible light active catalytic surface area and enhanced electrocatalytic activities for pollutant oxidation. Phenol, a highly toxic compound, was completely oxidized at an applied potential of 0.8 V vs. RHE under visible light irradiation. Systematic optimization of operational conditions for the photoelectrocatalytic oxidation of phenol was conducted. The phenol oxidation mechanism was elucidated via high-performance liquid chromatography (HPLC) analysis and the identification of intermediate compounds. Additionally, a mixed model of phenol and arsenic (III) in polluted water demonstrated the capability of WO3/MXene photoanode for the simultaneous oxidation of both organic and inorganic pollutants, achieving complete conversion of phenol and As(III) to non-toxic As(V). The WO3/MXene photoanode facilitated water oxidation, generating a substantial amount of O2•– and •OH oxidative species, which are crucial for the concurrent oxidation of phenol and arsenic. Recyclability tests demonstrated a 99% retention of performance, confirming the WO3/MXene photoanode's suitability for long-term operation in PEAOPs. The findings suggest that integrating WO3/MXene photoanodes into water purification systems can enhance economic feasibility, reduce energy consumption, and improve efficiency. This PEAOP offers a viable solution to the critical issue of heavy metal and organic chemical pollution in various water bodies, given its scalability and ability to preserve ecosystems while conserving clean water resources.

Characteristics of Pollution and Microbial Community Structure in the Antimony Mining Area of Longnan, Gansu Province

Antimony （Sb） is a major pollutant that poses a serious threat to the environment in the mining and processing of nonferrous metals, coexisting with sulfide and oxide of arsenic （As）. Microorganisms play an important role in the migration, transformation, and repair of metals in soil. The ecological effects of bioavailable Sb and As on the microbial community in antimony mining areas（mining and smelting areas）are still poorly understood. The Wenzel method and high-throughput 16S rDNA amplicon were used to characterize soil pollution characteristics in different functional areas, and the relationship between the bacterial community and bioavailable concentrations have been investigated comprehensively. The results showed that： Chemical speciation of Sb and As were amorphous, and poorly crystalline hydrous oxides of Fe and Al （F3） &gt; well-crystallized hydrous oxides of Fe and Al （F4） &gt; residual phases （F5） &gt; specifically adsorbed （F2） &gt; non-specifically adsorbed （F1）. According to the estimation of the potential ecological risk index （RI） and geo-accumulation index （Igeo）, the Sb pollution degree was： smelting area &gt; mining area &gt; contrast area, in which the smelting area showed serious pollution, and the mining area showed moderate to severe pollution. The As pollution degree was： mining area &gt; smelting area &gt; contrast area, in which the mining area and smelting area showed moderate to severe pollution. High-throughput 16S rDNA amplicon showed that Proteobacteria was the most abundant phylum in mining and smelting areas； Kaistobacter, Pseudomonas, Sphingomonas, and Lysobacter were the most abundant microbial genera； Geobacter and Luteolibacter had a high LDA score in mining areas； and Thiobacillus had a high LDA score in antimony-contaminated areas. Spearman correlation analysis, variation partitioning analysis （VPA）, and random forest （RF） analysis showed that Sb, As, bioavailable antimony [Sb （Bio）], and bioavailable arsenic [As （Bio）]were the main factors affecting the microbial community structure in different functional areas of antimony ore. Redundancy analysis （RDA） indicated that Sb and its bioavailable concentrations showed uniformly negative associations with the relative abundance of bacteria Nitrospirae and showed a significant positive correlation with Thiobacillus （P<0.05）. The in-depth research on the ecological effects of bioavailable Sb and As on the bacterial community provides references and new perspectives for environmental monitoring and management.

Microbial Sulfur and Arsenic Oxidation Facilitate the Establishment of Biocrusts during Reclamation of Degraded Mine Tailings.

Degraded tailings generated by the mining of metal ores are major environmental threats to the surrounding ecosystems. Tailing reclamation, however, is often impeded due to adverse environmental conditions, with depleted key nutrients (i.e., nitrogen (N) and phosphorus (P)) and elevated sulfur and metal(loid) concentrations. Formation of biocrusts may significantly accelerate nutrient accumulation and is therefore an essential stage for tailing reclamation. Although suggested to play an important role, the microbial community composition and key metabolisms in biocrusts remain largely unknown and are therefore investigated in the current study. The results suggested that sulfur and arsenic oxidation are potential energy sources utilized by members of predominant biocrust bacterial families, including Beijerinckiaceae, Burkholderiaceae, Hyphomicrobiaceae, and Rhizobiaceae. Accordingly, the S and As oxidation potentials are elevated in biocrusts compared to those in their adjacent tailings. Biocrust growth, as proxied by chlorophyll concentrations, is enhanced in treatments supplemented with S and As. The elevated biocrust growth might benefit from nutrient acquisition services (i.e., nitrogen fixation and phosphorus solubilization) fueled by microbial sulfur and arsenic oxidation. The current study suggests that sulfur- and arsenic-oxidizing microorganisms may play important ecological roles in promoting biocrust formation and facilitating tailing reclamation.

Arsenic Oxidation Kinetics with Plasmonic Nanocatalysts

Arsenic Oxidation Kinetics with Plasmonic Nanocatalysts

Elements characteristics and potential environmental risk assessment of jarosite residue and arsenic sulfide residue based on geochemical and mineralogical analysis

The waste slag known as jarosite residue (JR) and arsenic sulfide residue (ASR) were produced following the creation of zinc by hydrometallurgical procedures. The increasing annual zinc mining has led to growing pressure to dispose of the resulting JR and ASR from zinc smelting, making it crucial to assess their environmental impact and feasibility for utilization. The main components, distribution characteristics of elements, and potential environmental risks of zinc smelting wastes are studied through toxicity leaching tests, sequential extraction procedures, and various characterization technologies such as XRF, XRD, and SEM-EDS. The mineral compositions of JR are natrojarosite, franklinite, and gunningite, and zinc mainly adheres to the crevices of the natrojarosite mineral. Meanwhile, the ASR of flocculent structures is composed of orpiment, greenockite, arsenic oxide, and calvertite, and As appears in the form of the S-As-O phase. The Zn, Cu, and Cd in JR were dominated by exchangeable bound (81.53–96.6 %), and the main form of As, Cd, Se, and Tl in ASR was organic matter bound (87.0–99.21 %). The Risk Assessment Code (RAC) method confirmed the risk of Cd, Cu, Zn, and Mo in JR is high, while the risk of Cd, Pb, and Cr in ASR is moderate. Compared to the standard value of “Identification Standard for Toxicity of Hazardous Waste Leaching (GB5085.3-2007)”, the leachate concentrations of Zn in JR as well as Cd and As in ASR were exceeded, suggesting that the JR and ASR were in the type of hazardous waste and posed an environmental risk. The study provides theoretical guidance for the future rational management and effective utilization of hazardous waste.

Ars Genotype of Arsenic Oxidizing Bacteria and Detoxification

Objectives:The objectives of this study is bioremediation and detoxification of arsenite using arsenic resistance system (ars) genotypes of Arsenic Oxidizing Bacteria (AOB) isolated from highly As-contaminated mine.Methods:Bacterial strains that are resistant to arsenic were isolated from the Samkwang mine. The identification of AOB was conducted by analyzing the 16S rRNA gene using universal primers. To determine the genotypes of the arsenic resistance system (ars), specific primers were used for each gene. The extent of arsenic resistance was measured, and the efficiency of arsenite oxidation was assessed through a batch test. Arsenic concentration was measured using ICP-MS.Results and Discussion:The arsenic concentrations at site 1 of the Samkwang mine were found to be 1,322 mg/kg. This concentration is 26.4 times higher than the standard for soil pollution concerns (50 mg/kg) and 8.8 times higher than the standard for soil pollution measures (150 mg/kg). The appropriate remediation is studied such as bacterial remediation. The three efficient AOBs were identified as Agrobacterium tumefaciens EBC-SK1 (MF928870), Ochrobactrum anthrophi EBC-SK4 (MF928873), Ochrobactrum anthrophi EBC-SK12 (MF928881), respectively. The arsenic resistance system (ars) genotype were detected, which is the leader genes of the arsenic oxidation system (arsR and arsD), and the membrane gene (arsB). The arsB is involved in the encoding of the efflux/influx pumping system and moves arsenite into the bacterial cells. Arsenite-oxidizing (aox) genes are activated to oxidize arsenite into arsenate. The AOBs biotransform arsenite to arsenate with the regulation of ars genes, which detoxify highly As-contaminated mine.Conclusion:The AOBs from Samkwang mine are known for their resistance to highly toxic arsenic environments. They play a crucial role in the bioremediation of abandoned mines by transforming As(III) into As(V) through biotransformation.

Silica-supported ionic liquid for efficient gaseous arsenic oxide removal through hydrogen bonding

The emission of highly-toxic gaseous As2O3 (As2O3 (g)) from nonferrous metal smelting poses environmental concerns. In this study, we prepared an adsorbent (SMIL-X) by loading an ionic liquid (IL) ([HOEtMI]NTf2) into MCM-41 through an impregnation–evaporation process and then applied it to adsorb As2O3 (g). SMIL-20% exhibited an As2O3 (g) adsorption capacity of 35.48 mg/g at 400 °C, which was 490% times higher than that of neat MCM-41. Characterization of SMIL-X indicated that the IL was mainly supported on MCM-41 through O–H…O bonds formed between the hydroxyl groups (–OH) and the silanol groups (Si–OH) and the O–H…F bonds formed between the C–F groups and the Si–OH groups. The hydrogen bonds significantly contributed to the adsorption of As2O3 (g), with –NH and –OH groups forming hydrogen bonds with As–O species (i.e., N–H…O and O–H…O). This showed superior performance to traditional adsorbents that rely on van der Waals forces and chemisorption. Moreover, after exposure to high concentrations of SO2, the adsorption capacities remained at 76% of their initial values, demonstrating some sulfur resistance. This study presents an excellent adsorbent for the purification of As2O3 (g) and shows promising application potential for treating flue gas emitted by nonferrous metal smelting processes.

The influence mechanism of SO2 on the capture of gaseous arsenic by pyrolusite

Removal of gaseous arsenic from copper smelting flue gas by solid-phase adsorption effectively reduces the emission of arsenic-containing pollutants into the atmosphere. Nevertheless, the high concentration of SO2 in the flue gas unavoidably impacts the effectiveness of the adsorbent in capturing gaseous arsenic. Currently, there is no research focusing on the adsorption capacity of pyrolusite (PY) for As2O3(g), including the influence of SO2. This study examines the capacities of PY to capture As2O3(g) with and without SO2 under different conditions and delves into the mechanism by which SO2 affects the capture of As2O3(g) by PY. Compared to the states without SO2, the As2O3(g) capture by PY in an atmosphere containing SO2 (2.5 v/v% SO2) decreased to 89.1 % at 400 °C. SO2 can diminish the As2O3(g) capture capacity of PY by competing for active sites, generating sulfate (MnSO4), inhibiting arsenic oxidation, and obstructing the pores of the adsorbent. In addition, SO2 enhances PY's As2O3(g) capture capacity by creating (As2O2)SO4 and forming new active centers. Moreover, the phase transition of PY guided by the high concentration of SO2 during As2O3(g) capture also favors arsenic capture. This research confirms that PY has substantial potential for effectively removing As2O3(g) from high-SO2 flue gas.