Release kinetics of vanadium from vanadium (III, IV and V) oxides: Effect of pH, temperature and oxide dose

Batch experiments were performed to derive the rate laws for the proton-promoted dissolution of the main vanadium (III, IV and V) oxides at pH 3.1–10.0. The release rates of vanadium are closely related to the aqueous pH, and several obvious differences were observed in the release behavior of vanadium from the dissolution of V₂O₅ and vanadium(III, IV) oxides. In the first 2 hr, the release rates of vanadium from V₂O₃ were r = 1.14·([H⁺])^0.269 at pH 3.0–6.0 and r = 0.016·([H⁺])^? 0.048 at pH 6.0–10.0; the release rates from VO₂ were r = 0.362·([H⁺])^0.129 at pH 3.0–6.0 and r = 0.017·([H⁺])^? 0.097 at pH 6.0–10.0; and the release rates from V₂O₅ were r = 0.131·([H⁺])^? 0.104 at pH 3.1–10.0. The release rates of vanadium from the three oxides increased with increasing temperature, and the effect of temperature was different at pH 3.8, pH 6.0 and pH 7.7. The activation energies of vanadium (III, IV and V) oxides (33.4–87.5 kJ/mol) were determined at pH 3.8, pH 6.0 and pH 7.7, showing that the release of vanadium from dissolution of vanadium oxides follows a surface-controlled reaction mechanism. The release rates of vanadium increased with increasing vanadium oxides dose, albeit not proportionally. This study, as part of a broader study of the release behavior of vanadium, can help to elucidate the pollution problem of vanadium and to clarify the fate of vanadium in the environment.     

Oxidation of antimony (III) in soil by manganese (IV) oxide using X-ray absorption fine structure

The oxidation of antimony (III) in soils was studied using X-ray absorption fine structure (XAFS) spectra. An andosol soil sample and artificial soil samples (SiO₂ blended with iron (III) hydroxide and manganese (IV) oxide) were used herein. After adding antimony (III) oxide to all soil samples, the oxidation process was observed by recording the XAFS spectra of Sb K-edge, Fe K-edge, and Mn K-edge. The results indicated that manganese (IV) oxide played an important role in the oxidation of Sb(III); however iron (III) hydroxide was not directly related to the reaction. During a 2-hr continuous Sb K-edge X-ray absorption near edge structure (XANES) measurement with an interval of 1 min of one of the artificial soil samples (SiO₂ + MnO₂ + Sb₂O₃), a pseudo-first-order reaction was determined with an average estimated rate of 0.52 ± 0.04 hr^? 1. Compared to the lower oxidation rate of andosol, it is suggested that because of the low concentration of Mn(IV) in natural soils, the oxidation process of Sb(III) might be relatively slow and require more time to convert Sb(III) to Sb(V).     

Effects of Na+ on Cu/SAPO-34 for ammonia selective catalytic reduction

Copper-exchanged chabazite (Cu/CHA) catalysts have been found to be affected by alkali metal and alkaline earth ions. However, the effects of Na⁺ ions on Cu/SAPO-34 for ammonia selective catalytic reduction (NH₃-SCR) are still unclear. In order to investigate the mechanism, five samples with various Na contents were synthesized and characterized. It was observed that the introduced Na⁺ ion-exchanges with H⁺ and Cu^2 + of Cu/SAPO-34. The exchange of H⁺ is easier than that of isolated Cu^2 +. The exchanged Cu^2 + ions aggregate and form “CuAl₂O₄-like” species. The NH₃-SCR activity of Cu/SAPO-34 decreases with increasing Na content, and the loss of isolated Cu^2 + and acid sites is responsible for the activity loss.     

Study on the simultaneous reduction of methylmercury by SnCl2 when analyzing inorganic Hg in aqueous samples

Mercury (Hg) is among the most concerned contaminants in the world. It has three major chemical forms in the environment, including Hg⁰, Hg^2 +, and methylmercury (MeHg). Due to their differences in toxicity, mobility, and bioavailability, speciation analysis is critical for understanding Hg cycling and fate in the environment. SnCl₂ reduction-atomic fluorescence spectrometry detection is the most commonly used method for analyzing inorganic Hg. However, it should be noted that MeHg may also be reduced by SnCl₂, which would result in the overestimation of inorganic Hg. In this study, the reduction of MeHg by SnCl₂ in both de-ionized (DI) water and four natural waters was investigated. The results showed that MeHg could be reduced by SnCl₂ in DI water whereas this reaction was hard to occur in tested natural waters. By investigating the effects of water chemical characteristics (dissolved organic matter, pH and common anions and cations) on this reaction, SO₄^2 ? was identified to be the dominant factor prohibiting SnCl₂ induced MeHg reduction in natural waters. SO₄^2 ? in natural waters was evidenced to be reduced to S^2 ? by SnCl₂ and the generated S^2 ? can complex with MeHg to form MeHgS^? which is hard to be reduced by SnCl₂. Findings of this study indicate that the effect of MeHg reduction by SnCl₂ on inorganic Hg analysis is negligible in natural waters; however, at simulated experimental systems without SO₄^2 ?, SO₄^2 ? should be added as protecting agents to prevent MeHg reduction when analyzing inorganic Hg if it would not cause any other unwanted effects.     

Influence of gaseous and particulate species on neutralization processes of polar aerosol and snow — A case study from Ny-Ålesund

The inter-conversion of nitrogen and sulfur species between the gas and particulate phases and their interaction with alkaline species influences the acidity of the aerosols and surface snow. To better understand these processes, a short field campaign was undertaken in Ny-Ålesund, Svalbard, during 13th April 2012 to 24th April 2012. Air measurements were carried out through a particulate sampler equipped with denuders and filter packs for simultaneous collection of trace gases (HNO₃, NO₂, SO₂ and reactive nitrogen compounds) and aerosols, with daily collection of snow samples. Ionic composition of the samples was analyzed using ion chromatography technique. The results suggested that nitrate-rich aerosols are formed when PAN (peroxy acetyl nitrate) disassociates to form NO₂ and HNO₃ which further hydrolyzes to form pNO₃^? (particulate nitrate). This resulted in a high contribution of pNO₃^? (62%) to the total nitrogen budget over the study area. The acidity of the aerosols and snow evaluated through cation/anion ratio (C/A) indicated alkaline conditions with C/A > 2. The bicarbonates/carbonates of Mg^2 + played an important role in neutralization processes of surface snow while the role of NH₃ was dominant in aerosol neutralization processes. Such neutralization processes can increase the aerosol hygroscopicity causing warming. Chloride depletion in the snow was significant as compared to the aerosols, indicating two important processes, scavenging of coarse sea salt by the snow and gaseous adsorption of SO₂ on the snow surface. However, a more systematic and long term study is required for a better understanding of the neutralization processes and chemical inter-conversions.     

Degradation of sulfonamides and formation of trihalomethanes by chlorination after pre-oxidation with Fe(VI)

Sulfonamides are used in human therapy, animal husbandry and agriculture but are not easily biodegradable, and are often detected in surface water. Sulfamethazine (SMZ) and sulfadiazine (SDZ) are two widely used sulfonamide antibiotics that are used heavily in agriculture. In this study, they were degraded in an aqueous system by chlorination after pre-oxidation with ferrate(VI) (Fe^VIO₄^2 ?, Fe(VI)), an environmentally friendly oxidation technique that has been shown to be effective in degrading various organics. The kinetics of the degradation were determined as a function of Fe(VI) (0–1.5 mg/L), free chlorine (0–1.8 mg/L) and temperature (15–35°C). According to the experimental results, SMZ chlorination followed second-order kinetics with increasing Fe(VI) dosage, and the effect of the initial free chlorine concentration on the reaction kinetics with pre-oxidation by Fe(VI) fitted a pseudo-first order model. The rate constants of SDZ and SMZ chlorination at different temperatures were related to the Arrhenius equation. Fe(VI) could reduce the levels of THMs formed and the toxicity of the sulfonamide degradation systems with Fe(VI) doses of 0.5–1.5 mg/L, which provides a reference for ensuring water quality in drinking water systems.     

Nb2O5 nanowires in-situ grown on carbon fiber: A high-efficiency material for the photocatalytic reduction of Cr(VI)

Niobium oxide nanowire-deposited carbon fiber (CF) samples were prepared using a hydrothermal method with amorphous Nb₂O₅·nH₂O as precursor. The physical properties of the samples were characterized by means of numerous techniques, including X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), UV–visible spectroscopy (UV–vis), N₂ adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy. The efficiency for the removal of Cr(VI) was determined. Parameters such as pH value and initial Cr(VI) concentration could influence the Cr(VI) removal efficiency or adsorption capacity of the Nb₂O₅/carbon fiber sample obtained after hydrothermal treatment at 160°C for 14 hr. The maximal Cr(VI) adsorption capacity of the Nb₂O₅ nanowire/CF sample was 115 mg/g. This Nb₂O₅/CF sample also showed excellent photocatalytic activity and stability for the reduction of Cr(VI) under UV-light irradiation: the Cr(VI) removal efficiency reached 99.9% after UV-light irradiation for 1 hr and there was no significant decrease in photocatalytic performance after the use of the sample for 10 repeated cycles. Such excellent Cr(VI) adsorption capacity and photocatalytic performance was related to its high surface area, abundant surface hydroxyl groups, and good UV-light absorption ability.     

Simultaneous removal and oxidation of arsenic from water by δ-MnO2 modified activated carbon

The ubiquitous arsenic in groundwater poses a great risk to human health due to its environmental toxicity and carcinogenicity. In the present work, a new adsorbent, δ-MnO₂ modified activated carbon, was prepared, and its performance for the uptake of arsenate and arsenite species from aqueous solutions was investigated by batch experiments. Various techniques, including FESEM-EDX, p-XRD, XPS and BET surface area analysis, were employed to characterize the properties of the adsorbent and the arsenic adsorption mechanisms. The results showed that δ-MnO₂ covered on the surface and padded in the pores of the activated carbon. Adsorption kinetic studies revealed that approximately 90.1% and 76.8% of As(III) and As(V), respectively, were removed by the adsorbent in the first 9 hr, and adsorption achieved equilibrium within 48 hr. The maximum adsorption capacities of As(V) and As(III) at pH 4.0 calculated from Langmuir adsorption isotherms were 13.30 and 12.56 mg/g, respectively. The effect of pH on As(V) and As(III) removal was similar, and the removal efficiency significantly reduced with the increase of solution pH. Arsenite oxidation and adsorption kinetics showed that the As(V) concentration in solution due to As(III) oxidation and reductive dissolution of MnO₂ increased rapidly during the first 12 min, and then gradually decreased. Based on the XPS analysis, nearly 93.3% of As(III) had been oxidized to As(V) on the adsorbent surface and around 38.9% of Mn(IV) had been reduced to Mn(II) after As(III) adsorption. This approach provides a possible method for the purification of arsenic-contaminated groundwater.     

Performance and mechanism of Cr(VI) removal by zero-valent iron loaded onto expanded graphite

Zero-valent iron (ZVI) was loaded on expanded graphite (EG) to produce a composite material (EG-ZVI) for efficient removal of hexavalent chromium (Cr(VI)). EG and EG-ZVI were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and Brunauer–Emmett–Teller (BET) analysis. EG-ZVI had a high specific surface area and contained sub-micron sized particles of zero-valent iron. Batch experiments were employed to evaluate the Cr(VI) removal performance. The results showed that the Cr(VI) removal rate was 98.80% for EG-ZVI, which was higher than that for both EG (10.00%) and ZVI (29.80%). Furthermore, the removal rate of Cr(VI) by EG-ZVI showed little dependence on solution pH within a pH range of 1–9. Even at pH 11, a Cr(VI) removal rate of 62.44% was obtained after reaction for 1 hr. EG-ZVI could enhance the removal of Cr(VI) via chemical reduction and physical adsorption, respectively. X-ray photoelectron spectroscopy (XPS) was used to analyze the mechanisms of Cr(VI) removal, which indicated that the ZVI loaded on the surface was oxidized, and the removed Cr(VI) was immobilized via the formation of Cr(III) hydroxide and Cr(III)–Fe(III) hydroxide/oxyhydroxide on the surface of EG-ZVI.     

2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes migration ability of primary cultured rat astrocytes via aryl hydrocarbon receptor

Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed wound-healing assay and Transwell® motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations (10^? 10 and/or 10^? 9?mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mRNA expression of two pro-migratory genes, including cell division cycle 42 (CDC42) and matrix metalloproteinase 2 (MMP2) was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor (AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.     

原位载铁中孔活性炭吸附As和天然有机物效能

采用配煤、原位浸渍和两步活化法制备了4种原位载铁活性炭（FGL1/2/3/4）,并以空白炭C-GL为基础的表面铁浸渍后改性炭（Fe-GL-2/3/4）为对照,研究了原位载铁炭对水中As和腐植酸（HA）的同步吸附效能.结果表明,炭化料原位载铁促进了比表面积（S_BET）和中孔结构的发育.其中,原位载铁炭FCL4（载铁量6.51%）在45Å~480Å的范围内的中孔容积（V_mes）比C-GL增加了0.1146cm³/g;而后改性载铁则造成S_BET和V_mes的显著降低.原位载铁同时促进了表面碱度的增加,保证了中性条件下更好的As离子吸附能力;FCL4对As（Ⅲ）和As（V）的Langmuir最大吸附量（L-Q_max）分别达到2.566和2.825mg/g.原位载铁炭进一步发育的中孔结构促进了对HA（<10mg DOC/L）的吸附效能,FGL4对HA的Langmuir最大吸附量（Q_HA）达到46.25mg DOC/g.As-HA共存体系内FGL4对各组分的吸附容量有所降低,但As（Ⅲ）和As（V）的吸附容量仍达到2.325和2.675mg/g.     

Coordination geometry of Zn~(2+) on hexagonal turbostratic birnessites with different Mn average oxidation states and its stability under acid dissolution

Hexagonal turbostratic birnessite,with the characteristics of high contents of vacancies,varying amounts of structural and adsorbed Mn~(3+),and small particle size,undergoes strong adsorption reactions with trace metal(TM)contaminants.While the interactions of TM,i.e.,Zn~(2+),with birnessite are well understood,the effect of birnessite structural characteristics on the coordination and stability of Zn~(2+)on the mineral surfaces under proton attack is as yet unclear.In the present study,the effects of a series of synthesized hexagonal turbostratic birnessites with different Mn average oxide states(AOSs)on the coordination geometry of adsorbed Zn~(2+)and its stability under acidic conditions were investigated.With decreasing Mn AOS,birnessite exhibits smaller particle sizes and thus larger specific surface area,higher amounts of layer Mn~(3+)and thus longer distances for the first Mn\O and Mn\Mn shells,but a low quantity of available vacancies and thus low adsorption capacity for Zn~(2+).Zn K-edge EXAFS spectroscopy demonstrates that birnessite with low Mn AOS has smaller adsorption capacity but more tetrahedral Zn(~(IV)Zn)complexes on vacancies than octahedral(~(VI)Zn)complexes,and Zn~(2+)is more unstable under acidic conditions than that adsorbed on birnessite with high Mn AOS.High Zn~(2+)loading favors the formation of~(VI)Zn complexes over~(IV)Zn complexes,and the release of Zn~(2+)is faster than at low loading.These results will deepen our understanding of the interaction mechanisms of various TMs with natural birnessites,and the stability and thus the potential toxicity of heavy metal pollutants sequestered by engineered nano-sized metal oxide materials.     

Novel Fe/glass composite adsorbent and its property for arsenic(V) removal

An effective adsorbent for arsenic removal was synthesized by hydrothermal treatment of waste glass powder (HGP), followed by loading iron(III) oxyhydorxide on the surface of waste glass powder (GP). The ?Si-O-H group was formed on the surface of GP and the specific surface area of GP powder was slightly increased after hydrothermal treatment. FeOOH was loaded on the surface of HGP by the hydrolysis of FeCl3. The formation conditions of FeOOH were also investigated. The ability of this new adsorbent for arsenic removal was tested. The results indicate that the highest arsenic removal efficiency is about 97% for 1 mg/L As(V) solution at pH 6 and keeping time 2h.     

高比表面植物基活性炭吸附水中对硝基苯胺的性能及影响因素

以互花米草与棉秆为原料,以KOH为活化剂,制备了2种低成本高比表面微孔植物基活性炭SA-AC和CS-AC,通过静态实验研究了其对水溶液中对硝基苯胺的吸附特性,测定了溶液pH值、吸附剂剂量、溶液温度对吸附的影响,并探讨了等温吸附行为及其热力学性质.结果表明,在KOH与炭化料的质量比(剂料质量比)为3∶1、活化温度为800℃、活化时间为1.5 h条件下,活化制备的互花米草活性炭SA-AC和棉秆活性炭CS-AC的比表面积分别为2 825 m2.g-1和2 135 m2.g-1,微孔容积分别为1.192 cm3.g-1和1.011 cm3.g-1,对水溶液中对硝基苯胺的Langmuir最大吸附量分别为719和716 mg.g-1,远高于商业活性炭ST1300.溶液pH值和温度对吸附有较大影响,在低温及中性条件下有利于制备活性炭对水溶液中对硝基苯胺的吸附.Freundlich与Redlich-Peterson模型能很好地描述对硝基苯胺在2种活性炭上的吸附行为;热力学研究表明,吸附标准吉布斯自由能变ΔG0与标准焓变ΔH0均为负值,表明对硝基苯胺在这2种活性炭上的吸附属于自发的放热吸附过程;吸附标准熵变ΔS00,说明对硝基苯胺在活性炭表面上的迁移比在溶液中受到了更大的限制.     

CTAC改性活性炭去除水中砷(V)的柱实验吸附和再生研究

为了开发一种能有效去除水中砷的吸附材料, 研究了十六烷基三甲基氯化铵(CTAC)改性活性炭后, 活性炭对水中五价砷As(V)的去除效果.研究中利用动态小柱实验(Rapid small-scale column test, RSSCT)探讨了CTAC改性后活性炭对砷的吸附能力、影响吸附能力的因素和活性炭再生方法.结果表明, CTAC改性能有效提高活性炭对As(V)的吸附.活性炭对As(V)的吸附受溶液pH、空床接触时间、进水中砷浓度及水中其他离子存在的影响.另外, 1 mol·L^-1的盐酸能有效对吸附穿透后的活性炭进行再生,再生后的活性炭可以重复使用.同时,柱实验中对出水CTAC的检测结果表明, CTAC和活性炭的结合非常稳定.     

铁改性杭锦土吸附剂对水中砷的去除研究

为提高天然杭锦土对水溶液中砷的吸附性能,采用氯化铁（FeCl₃·6H₂O）浸渍天然黏土矿物杭锦土（HJ）,制备表面负载铁氧化物的铁改性杭锦土除砷吸附剂（FHJ）.通过比表面积（BET）和扫描电镜（SEM）分析技术对材料进行表征以观察其微观形貌特点,通过X射线光电子能谱分析（XPS）和傅里叶红外光谱（FTIR）技术测定材料组成及化学基团,以初步探究材料吸附除砷机理.通过批试验考察FHJ投加量、初始pH、共存离子及腐殖酸浓度对FHJ除砷效能的影响.结果表明:①当铁负载比在0~50wt%范围内时,FHJ对溶液中As（Ⅴ）吸附容量随着铁负载比的增加而增加,最佳铁负载比为33wt%,此时铁与杭锦土的理论质量比为1:3.②BET分析结果表明经铁改性后,杭锦土比表面积显著增加,由71.14 m2/g增至158.50 m2/g;SEM分析显示,经改性后杭锦土表面形貌发生明显变化,结合Mapping图表明铁被有效负载到杭锦土表面.③批试验结果表明,As（Ⅴ）去除率随着FHJ投加量的增加而升高;溶液pH对As（Ⅴ）去除率有较大的影响,pH的降低有利于FHJ对砷酸盐的吸附.④FHJ除砷性能受溶液中共存离子CO₃2-、SiO₃2-影响较大,但受Cl-、SO₄2-、NO₃-及腐殖酸影响程度比较小.⑤吸附动力学过程符合准二级动力学模型,Freundlich等温吸附模型可更好地描述FHJ吸附除砷行为（R2=0.999）.⑥XPS分析结果显示,铁氧化物主要以FeOOH和Fe₂O₃的形态负载于杭锦土表面,FTIR表明FeOOH的羟基基团同As（Ⅴ）发生吸附作用,在FHJ除砷过程中,化学吸附是主要的吸附除砷机理.研究显示,铁改性杭锦土除砷效果良好,具有一定的应用潜力.      

Novel Fe/glass composite adsorbent for As(V) removal

An effective adsorbent for arsenic removal was synthesized by hydrothermal treatment of waste glass powder (GP), followed by loading Fe(Ⅲ) oxyhydroxide onto the surface of waste glass powder. The ≡Si-O-H group was formed on the surface of GP and the specific surface area of GP powder was slightly increased after hydrothermal treatment. FeOOH was loaded onto the surface of hydrothermally treated waste glass powder (HGP) by the hydrolysis of FeCl3. The formation conditions of FeOOH were also investigated. The...     

活性炭纤维对水中铁的吸附研究

以活性炭纤维(ACF)为溶液中铁离子的吸附剂,考察了吸附时间、吸附温度、ACF比表面积及表面酸碱性对Fe3 吸附行为的影响.通过平衡吸附实验获得的吸附等温线,并不符合Langmuir与Freundlich经验吸附方程.吸附温度升高与ACF比表面积增加,都有利于铁离子的吸附,说明吸附过程同时具备物理和化学吸附行为的双重特征.ACF表面碱性基团是影响铁离子吸附的主要因素.     

负载型纳米铁吸附剂去除饮用水中As(Ⅴ)的研究

以活性炭为载体制备了一种负载型纳米铁吸附剂.纳米铁在活性炭孔内为针状,其直径为30～500 nm,长度为1 000～3 000 nm,载入量[m(Fe)/m(炭)]为82.1 mg/g.用1.5 g/L该吸附剂对pH 6.5、 (25±2)℃、 2 mg/L的As(Ⅴ)进行吸附其去除率为99.5%,在平衡浓度1.0 mg/L时,该吸附剂对As(Ⅴ)的吸附容量为15.4 mg/g;吸附速度较快,12 h可达91.4%,72 h达到吸附平衡.吸附过程可由孔内扩散模型较好地说明.除PO_4~(3-)、SiO_4~(2-)外其它常见阴阳离子均对As(Ⅴ)的去除影响不大.吸附剂可以用0.1 mol/L NaOH溶液再生,再生效率较高.实验室初步实验数据表明,该吸附剂对饮用水砷去除具有较好的应用前景.     

葡萄树基活性炭的制备及其CO2吸附特性

为探讨葡萄树基活性炭在碳捕集与封存领域中的潜力,分别以葡萄树枝和树皮为原料采用CO₂活化法在800℃下制备了葡萄树枝基活性炭和葡萄树皮基活性炭,根据N₂物理吸附法计算了比表面积,用二维非定域密度函数理论（2D-NLDFT）分析了孔径分布特性,并使用热重分析法表征了两种活性炭的热解特性以及30℃的CO₂吸附特性.结果表明:①葡萄树枝基活性炭具有微孔结构,微孔孔径在0.36~1.6 nm之间,孔径为0.66 nm的微孔最多;葡萄树皮基活性炭具有大量微孔和少量中孔,孔径主要集中在0.36~1.9 nm之间.②葡萄树枝基和葡萄树皮基活性炭的CO₂吸附容量分别为1.096和0.247 mmol/g.③两种活性炭的CO₂吸附以物理吸附为主,其CO₂饱和产物在45℃前释放全部CO₂,葡萄树枝基活性炭的CO₂饱和产物较葡萄树皮基活性炭的CO₂饱和产物难于释放CO₂.④两种活性炭吸附CO₂后,在热重特性上出现的微量变化表明活性炭物质结构上的变化.研究显示,葡萄树枝基活性炭是一种良好的CO₂捕集材料,但其CO₂吸附容量比其他同类活性炭低,CO₂吸附量较高的葡萄树基活性炭的制备条件和改性方法需要进一步研究.