JOURNAL OF HAZARDOUS MATERIALS
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2017
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IF 6.065
Weizhao Yin,Yongtao Li,Jinhua Wu,Guocai Chen,Gangbiao Jiang,Ping Li,Jingjing Gu,Hao Liang,Chuansheng Liu
A one-pot bio-iron system was established to investigate synergetic abiotic and biotic effects between iron and microorganisms on Cr(VI) removal. More diverse iron corrosion and reactive solids, such as green rusts, lepidocrocite and magnetite were found in the bio-iron system than in the Fe 0 -H 2 O system, leading to 4.3 times higher Cr(VI) removal efficiency in the bio-iron system than in the Fe 0 -H 2 O system. The cycling experiment also showed that the Cr(VI) removal capacity of Fe 0 in the bio-iron system was 12.4 times higher than that in the Fe 0 -H 2 O system. A 62 days of life-span could be achieved in the bio-iron system, while the Fe 0 -H 2 O system lost its efficacy after 30 days. Enhanced effects of extra Fe 2+ on Cr(VI) removal was observed, largely contributed to the adsorbed Fe 2+ on iron surface, which could function as an extra reductant for Cr(VI) and promote the electron transfer on the solid phase. The results also showed that the reduction of Cr(VI) by microorganisms was insignificant, indicating the adsorption/co-precipitation of Cr by iron oxides on iron surface was responsible for the overall Cr(VI) removal. Our study demonstrated that the bio-amended iron corrosion could improve the performance of Fe 0 for Cr(VI) removal from groundwater.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
CHEMOSPHERE
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2017
·
IF 4.208
Jun Wan,Xiaoqing Jiang,Tian C. Zhang,Jiong Hu,Dana Richter-Egger,Xiaonan Feng,Aijiao Zhou,Tao Tao
Finding a good sorbent for phosphorus (P) recovery from the aquatic environment is critical for preventing eutrophication and providing P resources. The activated iron system (mainly consisted of zero-valent iron (ZVI), Fe 3 O 4 and Fe 2+ ) has been reported to exhibit a favorable performance towards various contaminants in wastewater, but its effect on P recovery has not been studied systematically. In this study, we used Fe 2+ -nitrate pretreatment reaction to prepare the activated iron system and then applied it to P recovery. Results show that more than 99% P was removed from water in 60 min; co-existing anions (NO 3 − , Cl − and SO 4 2− ) and natural organic matter (NOM) had little effect on P removal. The P removal capacity of activated iron system is very high compared with currently reported sorbents. Externally-supplied Fe 2+ plays an important role on P removal in the system. Regeneration study shows that the activated iron system exhibited stable P recovery ability by using 0.1 M NaOH solution. Various methods were applied to characterize the ZVI and iron corrosion, and results conclude that sorption precipitation, and co-precipitation contribute to P removal. This method will be promising and have an application potential in the field for efficient and cost-effective recovery of P with cheap microscale zero valent iron.
研究领域:
环境科学
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水资源管理
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DOI
PubMed
高影响因子
Journal of Water Process Engineering
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2025
·
IF 6.7
Qian Zuo,Bing Li,Zhiyi Deng,Xiangyu Zheng,Ping Li,Jinhua Wu
Zero-valent iron (Fe 0 ) is widely packed in filters for Cr(VI) removal, but it suffers from ferrochrome precipitate passivation. In this study, a mixed Fe 0 and biochar (BC) system was established and investigated for promoted Fe 0 corrosion and enhanced Cr(VI) removal through iron‑carbon micro-electrolysis (IC-ME) by batch and column experiments with Fe 0 and BC as controls. Due to electrochemical reaction between Fe 0 and BC, there was an enhancement in iron corrosion and subsequent formation of secondary minerals on Fe 0 surface. These minerals included magnetite, lepidocrocite, and goethite, which facilitated Cr(VI) adsorption and reduction. The Fe 0 -BC system therefore obtained a higher Cr(VI) removal rate of 86.3 % within 6 h than those of the BC (7.9 %) and Fe 0 (12.5 %) systems. Chromium species distribution showed that 76.2 % of removed Cr(VI) was converted to Cr(III). The resultant Cr(III) of 68.4 % was immobilized on Fe 0 and BC surfaces due to precipitation and sequestration. The optimal Fe/BC mass ratio was 2:1 for galvanic reaction and Cr(VI) removal. The removal of Cr(VI) by Fe 0 -BC exhibited a pH-dependency, with acidic conditions favoring higher removal rates. Additionally, the column experiment result revealed that Cr(VI) removal capacity of 4.0 mg Cr(VI)/(g Fe 0 ) and operational lifespan of 1851 PV in the Fe 0 -BC column were 6.7 and 3.9-fold greater than those in the Fe 0 column, further confirming that galvanic reaction could effectively alleviate Fe 0 surface passivation. These results indicated that mixed Fe 0 and BC as an effective medium in filter tanks could form IC-ME to enhance Cr(VI) reduction and immobilization during water treatment.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 80
·76867-76873
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IF 3.289
Yunfei Zhang,Bo Yang,Jinhong Fan,Luming Ma
In this study, abrasives-reinforced metal matrix composites (MMCs) with a microscale size synthesized by ball milling (BM) could achieve highly active and stable dechlorination efficiency for aqueous 2-chlorophenol (2-CP). The preparation process of this composite via BM was optimized to obtain a high degradation efficiency, especially for the effect of the abrasives including B4C, SiC, α-Al2O3, SiO2, Fe3O4 and Na2SO4. The results showed that the hardness of the abrasives in the Fe-based MMCs was closely related with their dechlorination performance. Subsequently, the optimal abrasive, i.e. SiO2 was further investigated for its proper milling conditions with zero-valent iron (ZVI) particles including optimal SiO2 size, SiO2 loading, milling time, and the dosage of the process control agent (PCA). Additionally, the influence of other metal categories including Al and Si was also investigated for dechlorination; and their low reaction efficiencies were closely related with their passivating film. Finally, the longevity test suggested that the decreased reactivity of the SiO2–Fe MMC during the storage in air could be recovered when consecutively used, mainly due to the promoting effects of the inherent structure of SiO2–Fe MMC with the Fe/C and Fe/SiO2 interfaces, as well as the effective regeneration of the reactive sites by continuous iron dissolution.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Analytical Methods
·
2015
·Vol. 8
·期 6
·1239-1248
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IF 1.821
Shaolin Li,Yangyang Ding,Wei Wang,Hong Lei
Zero valent iron (ZVI) is increasingly used in large quantities for water treatment. In large-scale application of ZVI, a common question that engineers encounter is ZVI selection or its quality assurance and quality control (QA/QC). A facile method for assessing ZVI quality is proposed and studied in this work. The method is based on the Fe(III)–Fe(0) reaction that has a fast reaction rate, a known and simple stoichiometry, and an easy-to-assay product. The method is conducted by mixing the sample (e.g., testing ZVI) with concentrated Fe(III) solution (up to 3.0 g L−1) for 3–4 hours. The metallic iron (Fe(0)) content of the sample is obtained by assaying the final increase of the total dissolved iron, and its reactivity is quantified using the observed dissolution rate constants. The method is experimentally validated using 23 iron-based materials. Studies with reference iron powder and iron oxide demonstrate that the Fe(III) solution has satisfactory specificity in selecting Fe(0). Replicate experiments and t-test evaluation show the complete dissolution of the Fe(0) content in micron-scale ZVI and the high reproducibility of the method for measuring Fe(0). The accuracy and reliability of the method are studied using 15 commercial ZVIs of known Fe(0) purity, in a series of experiments using Fe(III), Cu(II) or trichloroethylene. The experiments show that the results from the proposed method are accurate and reliable, and that the method is a strong tool more effective than conventional techniques such as X-ray diffraction and BET-N2 adsorption. This work provides an easy and facile way for the quantitative assessment of the quality of metallic iron used for environmental clean-up, especially for the quick survey of a large number of iron samples on site. The method may also serve as a QA/QC procedure for ZVI in industrial-scale production.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
·
IF 6.735
Ying Lü,Zhanfeng Li,Jianfa Li,Kun Chen,Huaping Dong,Jianxin Shou,Yimin Li
In this work, a novel combination of pyrite with zero valent iron (ZVI) was used to enhance the efficiency of Cr(VI) removal in column experiments, simulating the operation of permeable reactive barriers (PRBs).The influence of pyrite dosage, initial pH, and the mixing manner on the removal efficiency were evaluated. The synergetic effect between pyrite and ZVI was found to contribute to enhanced Cr(VI) removal in column experiments using the ZVI/pyrite mixture, by which the Cr(VI) removal could be kept at >90% for 50–100 PVs in comparison with ∼30 PVs by using ZVI alone.The Cr(VI) removal efficiency by the ZVI/pyrite mixture was also much higher than the sum of those by ZVI and pyrite separately in the batch experiments. Mechanism investigations indicated that the synergetic effect was principally attributed to the more reactive Fe 2+ regenerated in the columns using the ZVI/pyrite mixture, due to reaction of pyrite with Fe 3+ produced during Cr(VI) reduction. In addition, pyrite could suppress the pH increase and retard the surface passivation of active materials. The by-product SO 4 2− from pyrite oxidation is also beneficial for enhanced removal efficiency. X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy-Energy dispersive spectrometry (SEM-EDS) studies confirmed the reduction of Cr(VI) into Cr(III), and that more pyrite was consumed in the Cr(VI) reduction by the ZVI/pyrite mixture. These findings are useful for developing cost-efficient methods for enhancing the removal of pollutants by ZVI-PRBs.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2019
·
IF 7.149
Yue Hu,Xing Peng,Zhihui Ai,Falong Jia,Lizhi Zhang
In this study, we report that liquid nitrogen treatment is a promising zero-valent iron activation method that does not remove the iron oxide shell; this can improve the apparent Cr(VI) removal rate constant of zero-valent iron by about 4–120 times, depending on the particle sizes and the suppliers of zero-valent iron. It was found that liquid nitrogen, with its low temperature of 77 K, could crack the iron oxide shell of zero-valent iron to produce abundant fractures because of the different thermal expansion coefficients of iron oxide and iron. These fractures provided suitable mass transfer channels for the inward transfer of water/oxygen molecules to the iron core and the subsequent in situ generation of Fe(II) for the reduction of Cr(VI) to Cr(III). More importantly, systematic characterizations confirmed the generation of an Fe(III)/Cr(III)/Cr(VI) composite on the surface of zero-valent iron during the removal, suggesting its environmental benignancy. This study provides a novel physical zero-valent iron activation method, sheds light on the importance of the iron oxide shell of zero-valent iron on Cr(VI) removal, and clarifies the intrinsic Cr(VI) removal mechanism of zero-valent iron.
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
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2019
·
IF 6.669
Chunhua He,Weishi Lin,Xiaohao Zheng,Chuanya Wang,Zhenhu Hu,Wei Wang
Anaerobic digestion is widely employed for treating phenol-containing wastewater, but there are still some drawbacks such as slow phenol degradation rate and vulnerable acetoclastic methanogens. Coupling of magnetite (Fe 3 O 4 ) and zero valent iron (ZVI) was firstly used to enhance anaerobic digestion of phenol. The results indicated an obvious synergistic effect was generated with coupling of Fe 3 O 4 and ZVI during the whole anaerobic digestion of phenol. The phenol degradation rate and methane production of Fe 3 O 4 /ZVI-added group were increased by 8.8–23.1% and 11.9–31.6%, respectively compared with Fe 3 O 4 -added group, and enhanced by 5.9–17.1% and 4.4–18.3%, respectively compared with ZVI-added group. ZVI improved the growth of hydrogenotrophic methanogens and Fe 3 O 4 enhanced the growth of syntrophic acetate-oxidizing bacteria. Finally, the syntrophic interaction between acetate-oxidizing bacterium and hydrogenotrophic methanogens played a vital role on the synergistic effect of Fe 3 O 4 and ZVI on the whole anaerobic phenol digestion.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Waseem Hayat,Yongqing Zhang,Ze-hua Liu,Xiaodong Du
The high leachability and solubility of methomyl (MET; C 5 H 10 N 2 O 2 S) result in water pollution; while, the polluted water channels can be depolluted by environmentally-friendly and highly-effective degradation technique. Therefore, MET degradation in water by peroxydisulfate (PDS) oxidation was investigated in this study employing the two most naturally-abundant iron species i.e. pyrite (PyR) and zero-valent iron (ZVI) as activators for PDS activation. The experiments were conducted at different activators’ dosage, pollutant concentration, oxidant concentration, initial pH and initial temperature for comparative assessment of degradation-efficiencies of PyR/PDS and ZVI/PDS systems. Using 0.25 g/L PyR/ZVI and 1.0 mmol/L PDS, PyR/PDS and ZVI/PDS systems respectively led to 98.8 % and 97.5 % degradation of 20.0 mg/L MET in 20 min, which became rapid by increasing the activators’ dosage and oxidant concentration in both systems. Further, the degradation has been more than 90.0 % at initial pH 3.0 to 11.0, which slowed with increasing the MET concentration in two systems. The free-radicals quenching analysis showed that degradation by PyR/PDS system was mainly executed by sulfate (SO 4 •− ) and hydroxyl ( • OH) radicals; while, SO 4 •− and super oxide radical anion (O 2 •− ) were dominant during degradation by ZVI/PDS system. PyR/PDS system had low stability and applicability, which supports the employment of ZVI/PDS system for efficient degradation of MET in water.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Jun Hu,Yifan Qiu,Bing Gu,Nv Yao,Zimo Lou,Zhuowei Cheng,Xianzhao Zhang,Jianming Yu
Zero-valent iron (Fe) is commonly employed as an additive for the mechanochemical destruction (MCD) of organic pollutants . The poly- and perfluoroalkyl substances (e.g., perfluorooctane sulfonate , PFOS) are a class of toxic environmental pollutants that are difficult to effectively degrade due to their thermodynamic and chemical stability. In this study, magnetite (Fe 3 O 4 ) was applied to improve the milling performance of Fe to PFOS and its promoting mechanisms were emphatically explored. The desulfurization rate was in ahead of the defluorination rate because the C–S bond is less stable than the C–F bonds in PFOS. Fe 3 O 4 had an excellent reinforcement effect on the milling performance of Fe, which was mainly through accelerating the electron transfer as a conductor, reacting with Fe to produce FeO, and facilitating the formation of HO ● . During the MCD of PFOS with Fe/Fe 3 O 4 as an additive, HO ● played a dominant role in the defluorination process (accounting for >67%). After the elimination of sulfonate group (−SO 3 − ), the produced radical (C 7 F 15 CF 2 ● ) continued to react through two main pathways: one was the stepwise defluorination after hydrogenation, and the other one was oxidation reaction after alcoholization to yield the corresponding aldehydes and carboxylic acids . The optimum Fe fraction (M Fe ) was 30%, and air atmosphere was more effective than oxygen and nitrogen conditions. This study helps to comprehensively understand the role of Fe 3 O 4 in defluorination and fills the gap of Fe/Fe 3 O 4 application in the MCD of PFASs.
研究领域:
环境科学
·
污染控制
·
化学工程
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DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2022
·
IF 6.437
Li Xiang,Haowen Li,Qipeng Qu,Fawei Lin,Beibei Yan,Guanyi Chen
Heavy oil residue (HOR) as a kind of oil-containing wastes (OW) is suitable to be treated by pyrolysis to obtain valuable products. However, the recovered products remain poor quality due to much heavy fractions in feedstock. This paper employed two typical steel wastes, i.e. iron-rich rolling sludge (FOS) and steel slags (SS), for catalytic pyrolysis of HOR to upgrade pyrolytic products. FOS and SS additions both effectively decreased the temperature of HOR pyrolysis stage and the activation energy . Compared with SS, FOS addition enhanced the yield of CH 4 and H 2 , leading to higher heating values for pyrolytic gases. However, insufficient FOS couldn’t provide enough energy to trigger the conversion of macromolecules as well as the cracking of short-chain alkanes and alkenes . In terms of pyrolytic oil, SS addition greatly improved the content of light fractions and exhibited stronger selectivity in reforming of alkanes into alkenes, while FOS addition promoted aromatization. Furthermore, Fe-doping carbon materials with different valent Fe and abundant defects were obtained through pyrolysis of HOR/FOS and HOR/SS. Combined with their magnetic properties, the separation of materials from contaminants and subsequent cycle utilization could be achieved. Subsequently, the addition of different Fe compounds validated the promotion of zero-valent Fe on aromatization while Fe 2 O 3 on alkenes production as well as Fe oxides would offer active oxygen species to participate in the pyrolysis reaction. However, model Fe compounds were hard to simulate catalytic behaviors of FOS and SS in gas production due to the complex components of steel wastes. This paper provides a novel perspective for upgrading all products from HOR pyrolysis and opens a path for simultaneous disposal of multiple solid wastes.
研究领域:
能源与燃料化学
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环境工程
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材料科学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yuhang Zhang,Hao Zhang,Nuanqin Zhang,Biao Zhou,Falong Jia,Lizhi Zhang,Zhihui Ai,Xiao Liu
Cadmium (Cd) contamination is highly toxic to human health, and the complexed Cd in wastewater is tricky to remove owing to its stable chelating structure. In this study, industrial zero-valent iron (ZVI) was modified by ball-milling with tiny formic acid (FA), and the as-prepared sample (FA-ZVI bm ) was attempted in the treatment of Cd II -ethylenediaminetetraacetic acid (Cd II -EDTA). Little FA addition to ball-milling could dramatically improve the performance of FA-ZVI bm towards Cd II -EDTA elimination and raise the elimination rate constant by more than 200 times. Results ascertained that the (HCOO) 2 Fe II shell formed on FA-ZVI bm promoted Cd II -EDTA decomplexation and activation of dissolved O 2 to reactive oxygen species (ROS) for oxidative degradation of EDTA ligands. Cd II -EDTA was instantly decomplexation by Fe 3+ replacement, and the decomplexed Cd 2+ was rapidly captured by FA-ZVI bm . At the same time, the EDTA ligands underwent oxidative degradation, avoiding the re-chelation ecological hazard. Interestingly, we found that replacement decomplexation has a synergistic mechanism for activating dissolved O 2 to ROS , facilitating oxidative destruction of EDTA ligands. Furthermore, the FA-ZVI bm fixed-bed reactor could remediate Cd II -EDTA contaminated environmental water one-stop, and the effluent stably meets the emission standards. This study demonstrated that FA-ZVI bm could be a viable approach for Cd II -EDTA decontamination and clarified the remediation mechanism.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）