JOURNAL OF MOLECULAR LIQUIDS
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2022
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IF 6.633
Min Xu,Xiaoli Ma,Yahui Chen,Luzeng Hu,Bo Wang,Muqing Qiu
Nanoscale zero-valent iron/biochar (nZVI/biochar) has been widely utilized in environmental remediation due to its excellent removal efficiency, easy synthesis, low-cost and environmental friendliness. Herein, the removal and interaction mechanism of Cr(VI) removal on nZVI/biochar was investigated by macroscopic and microscopic techniques. Compared to nZVI (25.84 mg/g), the high removal capacity (63.29 mg/g at pH 4.5), excellent reusability and chemical stability of nZVI/biochar were due to various oxygen-bearing functional groups and synergetic interaction. According to analysis of X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge fine (XANES) and extended X-ray absorption fine structure (EXAFS) spectra, the interaction mechanism of Cr(VI) on nZVI/biochar followed adsorption (complexation, electrostatic interaction), reduction and co-precipitation process with increasing reaction time. These findings are crucial for the application of nZVI/biochar for removal of heavy metals in actual environmental cleanup.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Di Zhang,Hao Tang,Bing Zhao,Lijie Liu,Hongwei Pang,Xiangxue Wang,Shujun Yu
Radioactive uranium removal plays a key role in energy development and environmental security. Sulfide nanoscale zero-valent iron (S-NZVI) has good antioxidant capacity, dispersibility and activity to eliminate U(VI) from wastewater, but the removal efficiency is limited. To improve the reduction and adsorption capacity of S-NZVI, through treating Fe 3+ solution by nitro-functionalized UiO-66 (UiO-66-NO 2 ) with high porosity, UiO-66-NO 2 enhanced S-NZVI adsorbent (S-NZVI/UiO-66) was prepared by liquid phase reduction method. The smaller size and larger specific surface area of S-NZVI/UiO-66 were confirmed by a variety of characterization techniques. Based on the excellent surface structure and reactivity, the U(VI) removal capacity of S-NZVI/UiO-66 (895 mg g −1 ) was much better than S-NZVI (434 mg g −1 ) and UiO-66-NO 2 (267 mg g −1 ). The impacts of pH, background ion strength, coexisting ions and different water environments on adsorption were studied via macroscopic batch experiments. The results showed that S-NZVI/UiO-66 could remove U(VI) adequately in a wide pH range. The removal rate was basically not affected by the concentration of NaNO 3 , demonstrating that the adsorption process of U(VI) on S-NZVI/UiO-66 tended to inner surface complexation. From XPS technique combined with the results of batch adsorption experiments, it was clear that the elimination mechanisms of U(VI) by S-NZVI/UiO-66 were mainly the physical adsorption, electrostatic attraction and complexation of UiO-66-NO 2 , and the reduction and complexation of S-NZVI. Therefore, it is believed that S-NZVI/UiO-66 has a great potential to be an excellent adsorbent in the field of the environment remediation. Moreover, S-NZVI/UiO-66 promises to be a novel nanomaterial for solving the problem of radionuclide contamination in practical environments.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2016
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IF 4.836
Shaolin Li,Wei Wang,Feipeng Liang,Wei-xian Zhang
Treatment of wastewater containing heavy metals requires considerations on simultaneous removal of different ions, system reliability and quick separation of reaction products. In this work, we demonstrate that nanoscale zero-valent iron (nZVI) is an ideal reagent for removing heavy metals from wastewater. Batch experiments show that nZVI is able to perform simultaneous removal of different heavy metals and arsenic; reactive nZVI in uniform dispersion brings rapid changes in solution E h , enabling a facile way for reaction regulation. Microscope characterizations and settling experiments suggest that nZVI serves as solid seeds that facilitate products separation. A treatment process consisting of E h -controlled nZVI reaction, gravitational separation and nZVI recirculation is then demonstrated. Long-term (>12 months) operation shows that the process achieves >99.5% removal of As, Cu and a number of other toxic elements. The E h -controlled reaction system sustains a highly-reducing condition in reactor and reduces nZVI dosage. The process produces effluent of stable quality that meets local discharge guidelines. The gravitational separator shows high efficacy of nZVI recovery and the recirculation improves nZVI material efficiency, resulting in extraordinarily high removal capacities ((245 mg As + 226 mg-Cu)/g-nZVI). The work provides proof that nanomaterials can offer truly green and cost-effective solutions for wastewater treatment.
研究领域:
环境科学
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水处理
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纳米技术
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
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IF 8.355
Bowei Zhang,Ying Guo,Junyu Huo,Huijun Xie,Chunhua Xu,Shuang Liang
Total petroleum hydrocarbon (TPHs) has been posing a threat to soil health as its increasing production and application. For the better remediation and reclamation of TPHs polluted soil, the combined remediation by persulfate (PS) with biochar supported nano iron (BC-nZVI) was proposed and verified. In this study, the activators (BC-nVZI and nZVI) were synthesized through ferrous reducing by sodium borohydride under nitrogen with or without BC addition. The optimal concentration of 15% PS (w/w) was selected and applied to treat the TPHs polluted soil over 60 days. The TPHs degradation underwent two different stages, including chemical degradation (0th–6th day) and biodegradation (6th–60th day). To clarify the degradation process during remediation, the carbon chain transformation was tested. During the whole remediation period (0th–60th day), the long chain TPHs constantly degraded and transformed into short chain molecules in the BC-nZVI/PS groups. Furthermore, comparing with nZVI/PS groups, the BC-nZVI/PS groups could increase the soil microbial metabolic activities during the remediation period. Microbial analysis showed that the PS activation groups could significantly affect microbial abundance and structure. In BC-nZVI/PS groups, the microbial abundance recovered and TPHs-degradation bacterium increased over 60 days. This study gives an innovative technology for the TPHs polluted soil remediation which could achieve the goal for soil bioremediation after PS oxidation.
研究领域:
环境科学
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土壤化学
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微生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
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2024
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IF 1.5
Lei Miao,Zhang Jun,Liu Chang,Guo Junpeng,Li Ye
Herein, S-nZVI was synthesized to remove U(VI) from seawater. At a S/Fe ratio of 0.18 and pH of 5, adsorption of U(VI) reached equilibrium after 20 min with the removal rate of 97.93%. And the maximum adsorption capacity obtained by Langmuir isothermal model was 1177.09 mg/g. Moreover, S-nZVI exhibited selectivity in the presence of interfering ions, regeneration performance in 5 reuse cycles, and high removal efficiency in actual seawater. Mechanism investigations showed that UO 2 2+ uniformly adsorbed on S-nZVI surface was irreversibly reduced and generated UO 2 precipitates due to the electrons provided by S 2− , S 2 2− and Fe(II).
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 9
·e202302529
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IF 1.9
Mingyue Piao,Xue Peng,Hao Liu,Wei Zhang,Honghui Teng
Graphical nZVI/MCM-41/rGO is designed for improving the properties of nZVI, and the results show that it has an apparent Fe(0) crystallinity and modest rGO crystallinity, as well as a rough and porous structure. There are many oxygen-containing groups found on the surface of nZVI/MCM-41/rGO, such as −OH, −COOH, and Si−O. The pore diameter is concentrated at 23.82 nm, and the specific surface area is 15.94 cm 2 /g. The best performance is occurred at pH 6, C 0 =80 mg/L with a 2 g/L adsorbent dosage, and after 180 min, a maximum adsorption capacity of 41.82 mg/g is reached at 333 K. The Dubinin-Radushkevich isotherm and second order kinetic models fit the Ni(II) adsorption process well. It is determined through analysis of the thermodynamic parameters that the adsorption progress is endothermic (ΔH 0 >0) and spontaneous (ΔG 0 <0). nZVI/MCM-41/rGO has proven to be an effective and alternative material for the removal of Ni(II) ions from aqueous media due to its excellent removal ability, availability, and low cost. Emissions of nickel (Ni) are harmful to the environment and people‘s health. Although nano zero-valent iron (nZVI) has a lot of potential for treating water pollution, its instability and tendency for aggregation have limited its application. In order to improve its properties, composite adsorbent MCM-41/rGO supported nZVI (nZVI/MCM-41/rGO) is designed for improving the properties of nZVI, and it is characterized by SEM, XRD, FTIR and BET. The results show that it has an apparent Fe (0) crystallinity and modest rGO crystallinity, as well as a rough and porous structure. There are many oxygen-containing groups found on the surface of nZVI/MCM-41/rGO, such as −OH, −COOH, and Si−O. The pore diameter is concentrated at 23.82 nm, and the specific surface area is 15.94 cm 2 /g. The consequences of several parameters such as contact time, initial metal ion concentration, adsorbent dosage, and pH for adsorption efficiency were investigated. The best performance is occurred at pH 6, C 0 =80 mg/L with a 2 g/L adsorbent dosage, and after 180 min, a maximum adsorption capacity of 41.82 mg/g is reached at 333 K. The Dubinin-Radushkevich isotherm and second order kinetic models fit the Ni(II) adsorption process well. It is determined through analysis of the thermodynamic parameters that the adsorption progress is endothermic ( ΔH 0 >0) and spontaneous ( ΔG 0 <0). nZVI/MCM-41/rGO has proven to be an effective and alternative material for the removal of Ni(II) ions from aqueous media due to its excellent removal ability, availability, and low cost.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Wenpei Wu,Lu Han,Xiang Nie,Mingyue Gu,Jing Li,Mengfang Chen
The multiple injections of nanoscale zero valent iron (nZVI) slurry, an efficient method to remediate contaminated groundwater, requires an accurate assessment of the transport and risks of these particles in saturated porous medium . However, the influencing mechanism of nZVI transport under multiple injection conditions is not fully understood. In this experimental study, one-dimensional sand columns were used to evaluate the effects of injection concentrations, particle sizes and surface chemical corrosion on the transport of carboxymethyl cellulose modified nZVI (CMC-nZVI) under triple injection conditions, where the different volumes of NaCl solution were flushed through the columns between the injections. Based on the breakthrough curves and retention profiles under flushing 4 pore volumes of NaCl solution between the injections, the transport of CMC-nZVI particles was gradually enhanced attributable to the exclusion among these particles at injection concentration of 200 mg/L, but the opposite was observed due to large aggregation caused by strong magnetic force among particles at 500 mg/L. However, the magnitudes of enhancement or reduction on maximum C/C 0 under the above injection concentrations were related to the smallest particle size of D h = 3.926 μm because of high particle number concentrations leading to intense competition on depositional sites at 200 mg/L and significant aggregation at 500 mg/L. Conversely, the transport of CMC-nZVI was reduced under flushing 76 pore volumes of NaCl solution between the injections because of pronounced corrosion of CMC-nZVI in water as evidenced by the XPS and XRD analyses of particles. This corrosion could cause the decrease in repulsion among particles due to the increase in surface negative zeta potential and the CMC desorption from nZVI. Accordingly, this study revealed that relative high injection concentrations and chemical corrosion in groundwater could restrain the mobility of nZVI under multiple injection conditions and the potential risks posed by CMC-nZVI are controllable.
研究领域:
环境科学
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地下水修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Nano
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2024
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IF 5.8
Qi Cheng,Qingrui Li,Xiaoqin Li,Weizhen Liu,Zhang Lin,Liyuan Chai
Nanoscale zero-valent iron (nZVI) and modified nZVI have shown great removal capacities towards various heavy metals. However, the aging process of nZVI during the reaction is crucial for the long-term affinity and stability of heavy metals in the environment. In this study, the aging and iron oxide evolution of amorphous nZVI (A-nZVI) and nZVI during the reaction with Sb(III) were investigated and compared. The results indicated that after reacting with Sb(III), iron oxides in A-nZVI were mainly composed of γ-Fe2O3 (33.9%) and γ-FeOOH (29.8%), whereas α-Fe2O3 (24.9%) and α-FeOOH (31.8%) were dominant in the aged nZVI. The removal capacities for Sb(III) of γ-Fe2O3 (69.8 mg g−1) and γ-FeOOH (42.3 mg g−1) were both much higher than those of α-Fe2O3 (4.3 mg g−1) and α-FeOOH (8.4 mg g−1). Sb(III) was partially oxidized during the reaction, and DFT calculation showed that the adsorption energies of both Sb(III) and Sb(V) on γ-Fe2O3 and γ-FeOOH were higher than those on α-Fe2O3 and α-FeOOH. Furthermore, EXAFS analysis revealed that Sb formed an inner-sphere complex with the iron oxides in A-nZVI through the bidentate mononuclear edge-sharing structure (2E). Therefore, A-nZVI showed higher affinity and long-term stability toward Sb(III) remediation.
研究领域:
环境科学
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材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2022
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IF 7.926
Junyuan Guo,Jianying Jiang,Yihua Chen,Xiaoying Wen,Wenjing Chen,Yifan Wang,Lin Su,Jing Cao
In order to achieve efficient adsorptive and oxidative removal of pyrene, a persulfate oxidation system with composite nZVI-BC prepared by loading nano-zero-valent iron on coconut shell biochar as an activator was established and applied. The results of adsorption experiments showed that at pH 3, when the dosages of BC, nZVI and nZVI-BC were all 1.5 g/L, the removal efficiency of pyrene reached 64.9%, 19.0%, and 61.2%, respectively after 120 min of adsorption. The best performance of nZVI-BC-persulfate system was achieved at pH 3, nZVI-BC 1.2 g/L and persulfate concentration 6 mM, and after 60 min of degradation, the removal efficiency of pyrene reached 99.4%. The pre-adsorption process was a promoting-step for pyrene degradation. The conversion of nZVI to Fe 2+ and Fe 3+ played an important role in the activation of persulfate to produce SO 4 •− and • OH, both of which were responsible for non-selectively oxidization pyrene. The support of BC could improve the dispersibility and activity of nZVI and improve of the above conversion. The intermediates with relatively lower toxicity were identified during pyrene degradation, and they were successively oxidized into CO 2 and H 2 O finally. In summary, nZVI-BC can be a promising catalyst for persulfate activation to degrade PAHs in wastewater.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Chengfang Zhang,Zhenyu Song,Chao Li,Qinglong Liu,Jingchun Tang
In the actual polluted environment, the composite pollution system was usually composed of heavy metals and organic pollutants, especially Cr(VI) and chlorophenols often co-existed in industrial wastewater. In this study, a composite material consisting of multilayer graphene carbon shells coated with nZVI (gBC@nZVI) with various excellent properties was applied to deal with the composite system of Cr(VI) and 2,4-dichlorophenol (2,4-DCP) coexisting in the wastewater, and the intrinsic mechanism for the simultaneous removal of heavy metals and organic pollutants was systematically investigated. The results showed that in the composite pollution system (Cr(VI) = 20 mg/L, 2,4-DCP = 15 mg/L), complete removal of Cr(VI) could be achieved in 60 min, while 2,4-DCP achieved 95.2 % removal, with the contribution of oxidative degradation being 76.4 %. It was found that during the efficient adsorption and reduction of Cr(VI) by gBC@nZVI, the generation of the metastable intermediate Cr(V) was verified by probe compounds, electron spin resonance and UV–visible spectroscopy, and further experiments demonstrated that the generation of •OH was closely related to Cr(V) and promoted the oxidative degradation of the coexisting 2,4-DCP. Quenching experiments with the addition of specific scavengers indicated that •OH was the active species directly dominating the oxidative degradation of 2,4-DCP, whereas Cr(V) was indirectly involved in the degradation of 2,4-DCP by promoting the generation of •OH. In addition, the increase of solution pH negatively affected the degradation of 2,4-DCP in the composite polluted system, mainly due to the hindered generation of •OH in the alkaline environment. This work provided theoretical support for the promising application of gBC@nZVI in real environments contaminated with a combination of Cr(VI) and chlorophenols.
研究领域:
环境科学
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水处理技术
·
污染控制
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
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IF 2.752
Zeyu Guan,Yajie Shu,Yongwen Ma,Jinquan Wan
A novel core–shell amino-functionalized silica coated nanoscale zero valent iron (NH 2 –SiO 2 @NZVI) was prepared by the combination of liquid phase reducing method and improved Stöber method. The surface, structure and characteristics of the nanoparticles (NPs) were investigated by transmission electron microscope (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and the elemental analysis. It was found that the appropriate dropping rate of NaBF 4 and the proper usage of 3-aminopropyl trimethoxysilane (APTMS) were the crucial and key step for the formation of highly uniform and desirable NH 2 –SiO 2 @NZVI particles. SEM, XRD results showed that the obtained NH 2 –SiO 2 @NZVI NPs has a good dispersibility and antioxidant capacity with the particle size around 120 nm, BET surface area around 123.38 m 2 /g when NaBH 4 dropping speed was 1 ml/min and the usage of APTMS was 0.3 ml/ml tetraethyl orthosilicate (TEOS). NH 2 –SiO 2 @NZVI particles can effectively adsorb TCP with the first-order rate constant k obs of 0.0204 h −1 in 18 h and remove with a removal efficiency of 45.62% in 48 h.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Yang Huang,Weihua Zhang,Maosheng Zhang,Xin Zhang,Yunmeng Zhao
In this study, salicylic acid-TiO 2 @SiO 2 @Ni/nZVI (SA-NFST) nanocomposites with rich hydroxyl groups were synthesized using in situ surface modified, co-precipitation, and sol-gel methods. A variety of techniques, including scanning electron microscopy (SEM), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), the point of zero charge (PZC), UV–vis diffuse reflectance spectra (UV–vis), infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), were used to characterize the properties of the nanoparticles. The results showed that the SA-NFST exhibited high visible light-harvesting efficiency, easily magnetic separation, rich hydroxyl groups and hydroxyl radicals, and larger surface area. The adsorption and photo-oxidation of arsenite by the new materials were explored in different experimental conditions, including pH, initial arsenite concentration, catalyst dosage, contact time, and coexisting anions (PO 4 3− , SiO 3 2− , CO 3 2− , and SO 4 2− ). The maximum adsorption capacities ( q m ) of As(III) onto SA-NFST calculated from Langmuir adsorption isotherm were 73.9 and 83.6 mg/g without and with visible light irradiation, respectively. >99.8% of As(III) (5.0 mg/L) was removed in the presence of 0.25 g/L SA-NFST nanoparticles (NPs) under 1.5 h visible light illumination. The residual concentration of As(III) (9.0 µg/L) was less than 10 µg/L, which is below the maximum allowable values in drinking water. As(III) removal may be due to the synergic combined effects of surface adsorption, photocatalytic oxidation under visible light illumination.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）