CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Shi-Xu Wang,Yun-Xin Huang,Hao Wang,Yao-Yao Lu,Wen-Long He,Jing Li,Nian-Si Fan,Bao-Cheng Huang,Ren-Cun Jin
Exploiting phosphorus resources from waste streams such as municipal wastewater is essential for their recycling and utilization. However, common practice on phosphorus recovery via main-stream biological phosphorus removal and side-stream phosphorus precipitation still faces great challenges such as organic mineralization induced CO 2 emission and aeration caused energy consumption. In this work, ferrihydrite and magnetite were respectively dosed into bioflocculation organic carbon capture system to comprehensively evaluate their potential improvements on phosphorus recovery from municipal wastewater. Results showed that ferrihydrite would outcompete magnetite on phosphorus capture, by increasing TP removal efficiency from 17.5% to 91.2% while maintaining a high organic carbon capture efficiency of about 50%. Although both iron minerals were favored for improving sludge settling performance, the potential toxicity of magnetite was higher than that of ferrihydrite. Chemical precipitation and adsorption are the main pathways for phosphorus removal by iron minerals. Subsequent anaerobic fermentation showed that ferrihydrite bounded phosphorus was mainly transformed to vivianite while magnetite captured phosphorus was released into the liquid. Surprisingly, ferrihydrite was favored for the volatile fatty acids rather than biogas production, with an average yield of 523.2 mg/g volatile suspended solids. This work might be valuable for exploring a more sustainable value-added resource recovery paradigm.
研究领域:
环境工程
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污水处理
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资源回收
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Huili Han,Wanzhong Yin,Bin Yang,Donghui Wang,Jin Yao,Zhanglei Zhu
This work systematically studied the adsorption behavior of sodium oleate (NaOL) on hematite , limonite, and siderite and their corresponding flotation performance at alkaline pH . The adsorption behavior and conformation of NaOL on mineral surfaces were investigated using zeta potential analysis, Fourier-transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy spectra (XPS), and atomic force microscopy (AFM) imaging characterization. The effect of NaOL adsorption on the surface wettability and bubble-particle attachment was further analyzed by contact angle measurement, attachment time tests, and wrap angle tests. Finally, batch flotation tests and kinetic analysis were carried out to evaluate three mineral flotation behaviors. The results revealed that NaOL could chemically adsorb on hematite, limonite, and siderite and caused the significant negative mobility in their zeta potentials. It was found that Fe atoms exposed on their surface were the main active centers for the chemisorption of NaOL. Hematite and limonite had more active sites for NaOL adsorption than siderite, and Fe(III) on hematite and limonite surface could interact more strongly with NaOL than Fe(II) on siderite, which resulted in the higher adsorption density and intensity of NaOL on hematite and limonite than that on siderite. This further contributed to the stronger hydrophobicity on their surface than that on siderite surface. The enhancement of hydrophobicity could increase the attachment efficiency of bubble-particle ( E a ). Therefore, hematite and limonite particles had more and faster attachment with bubbles than siderite particles. As such, much higher cumulative ultimate recoveries ( R ∞ ) and flotation rate constants ( k ) of hematite and limonite than those of siderite were obtained.
研究领域:
矿物学
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表面化学
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浮选工艺
✓ 已验证
产品关联
DOI
高影响因子
Journal of Experimental Nanoscience
·
2013
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IF 0.875
Hongtao Cui,Wanzhong Ren,Peng Lin,Yan Liu
Iron oxide polymorph nanoparticles (magnetite, goethite and lepidocrocite) were synthesised through a novel epoxide precipitation route. Epoxide, as a precipitating agent, induced the precipitation of iron(II) ions in the form of hydroxide through its reaction with aquocomplexes of Fe2+ ions. The organic intermediate, which was produced from the ring-opening reaction of epoxide, functionalised the surface of the formed precipitate in situ, resulting in the minimisation of the nanoparticles’ aggregation. Another advantage of this route is its simple procedure for the preparation of iron oxide nanoparticles with different structures and their well-defined morphology. Magnetite, goethite and lepidocrocite nanoparticles were obtained just by the pH regulation and air oxidation at room temperature.
研究领域:
材料科学
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化学工程
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Central South University
·
2025
·
IF 4.4
Zhu Qiang,Yang Jian-guang,Nan Tian-xiang,Zeng Wei-zhi,Tang Shi-yang,Liu Jiang,Zhang Yan,Tang Chao-bo
The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste, produced in large quantities, and results in significant zinc loss. The study was conducted on removing iron from FeSO 4 -ZnSO 4 solution, employing seed-induced nucleation methods. Analysis of the iron removal rate, residue structure, morphology, and elemental composition involved ICP, XRD, FT-IR, and SEM. The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid. Concurrently, iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield. The results revealed that seed addition increased the iron removal rate by 3%, elevated the residual iron content by 6.39%, and mitigated zinc loss by 29.55% in the simulated solution. Seed-induced nucleation prevented excessive nuclei formation, fostering crystal stable growth and high crystallinity. In addition, the zinc content of surface adsorption and crystal internal embedding in the residue was determined, and the zinc distribution on the surface was dense. In contrast, the total amount of zinc within the crystal was higher. The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth, and the zinc loss per ton of iron removed was reduced by 50.91 kg (34.12%) and the iron residue reduced by 0.17 t (8.72%).
研究领域:
冶金学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Lixia Yan,Qingze Chen,Yixuan Yang,Runliang Zhu
With high surface reactivity and weak crystallinity , ferrihydrite (Fh) tends to be transformed to other thermodynamically stable iron (hydr)oxides, and its transformation is strongly influenced by the coexisting substances. Clay minerals widely coexist with Fh in the near-surface areas, but there is limited information about their effects on the transformation of Fh. In this work, the effect of montmorillonite (Mt) on the formation of hematite (Hem) nanoparticles from Fh under heat treatment was studied. Fh, Mt, and their mixed samples (Fh-Mt) were heated at different temperatures (350, 450, 600, 700, and 800 °C) for various times (3, 5, and 10 h), and the samples before and after heating were well characterized. X-ray diffraction and 57 Fe Mössbauer spectroscopy results revealed that Fh was transformed to Hem after heat treatment in both the presence and absence of Mt. Scanning electron microscopy and transmission electron microscopy images indicated that Mt could well disperse Fh and distinctly decrease the particle sizes of the formed Hem after heating. In particular, the particle size of Hem reached ~1000 nm in the pure Fh system, while it was only 15–75 nm in the systems containing Mt. Fourier transform infrared spectroscopy patterns displayed the strong interactions between Mt and Fh (through the formation of Si−O−Fe and Al−O−Fe bonds), which may also reduce the aggregation of Fh and inhibit the phase transformation of Fh particles into large Hem particles. This work verifies the important protective effect of clay minerals on coexisting iron oxide under high-temperature conditions, which would contribute to better understanding the formation and preservation of natural nano-sized minerals (particles) in nature.
研究领域:
地质学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Yuting Zhang,Jiaqi Wang,Xuesong Zhang,Wenxiu Qin,Youbin Si
Preliminary studies have demonstrated that light can facilitate the biogeochemical cycling of iron, influencing the valence state of heavy metals, solidifying them, and ultimately achieving detoxification effects. However, few studies have focused on the oxidation of Sb(III) in different iron minerals and the differences in mechanisms. This study explored the photooxidation of Sb(III) in the presence of various iron minerals (hematite, pyrite and goethite), focusing on how different iron minerals influenced the oxidation process and the mechanisms involved. Among the minerals tested, pyrite exhibited exceptional photooxidation performance, achieving an Sb(III) oxidation efficiency of 67.03% after 300 minutes. This superior photooxidation activity correlated with pyrite’s significant Fe(II) yield (11.70 μg/L). Our study demonstrated that light irradiation enhanced Sb(III) oxidation through three iron-based minerals. Light exposure drove the generation of Fe(II) within these minerals, initiating Fe(II)/Fe(III) redox cycling. This process promoted reactive oxygen species (ROS) generation, including hydroxyl radicals (•OH), superoxide radicals (O 2 •− ) and hydrogen peroxide (H 2 O 2 ), which collectively mediated Sb(III) oxidation to the less toxic Sb(V). In the photooxidation of Sb(III), •OH played a critical role in reactions involving hematite and pyrite, while O 2 •− dominated in goethite and pyrite systems. H 2 O 2 was found to have a pivotal role across all three iron mineral systems. Additionally, photogenerated holes ( h + ) significantly enhanced Sb(III) oxidation in the pyrite system. This research highlighted the impact of light on the biogeochemical cycling of iron and its role in facilitating the oxidation of Sb(III) through reactions that involve photo-generated electrons and free radicals.
研究领域:
环境科学
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地球化学
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光催化
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生物地球化学
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环境化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
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2018
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IF 3.12
Zheng Chen,Yaxian Zhang,Qingliu Luo,Liuying Wang,Shurui Liu,Yajuan Peng,Haitao Wang,Liang Shen,Qingbiao Li,Yuanpeng Wang
Microbially mediated bioreduction of iron oxyhydroxide plays an important role in the biogeochemical cycle of iron. Geobacter sulfurreducens is a representative dissimilatory iron-reducing bacterium that assembles electrically conductive pili and cytochromes . The impact of supplementation with γ-Fe 2 O 3 nanoparticles (NPs) (0.2 and 0.6 g) on the G. sulfurreducens -mediated reduction of ferrihydrite was investigated. In the overall performance of microbial ferrihydrite reduction mediated by γ-Fe 2 O 3 NPs, stronger reduction was observed in the presence of direct contact with γ-Fe 2 O 3 NPs than with indirect contact. Compared to the production of Fe(II) derived from biotic modification with ferrihydrite alone, increases greater than 1.6- and 1.4-fold in the production of Fe(II) were detected in the biotic modifications in which direct contact with 0.2 g and 0.6 g γ-Fe 2 O 3 NPs, respectively, occurred. X-ray diffraction analysis indicated that magnetite was a unique representative iron mineral in ferrihydrite when active G. sulfurreducens cells were in direct contact with γ-Fe 2 O 3 NPs. Because of the sorption of biogenic Fe(II) onto γ-Fe 2 O 3 NPs instead of ferrihydrite, the addition of γ-Fe 2 O 3 NPs could also contribute to increased duration of ferrihydrite reduction by preventing ferrihydrite surface passivation. Additionally, electron microscopy analysis confirmed that the direct addition of γ-Fe 2 O 3 NPs stimulated the electrically conductive pili and cytochromes to stretch, facilitating long-range electron transfer between the cells and ferrihydrite. The obtained findings provide a more comprehensive understanding of the effects of iron oxide NPs on soil biogeochemistry .
研究领域:
微生物学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Nano
·
2017
·Vol. 4
·期 12
·2395-2404
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IF 6.047
Hong-Wei Luo,Xin Zhang,Jie-Jie Chen,Han-Qing Yu,Guo-Ping Sheng
Although the existence of Fe(III) (hydr)oxide nanoparticles (NPs) in natural environments has been recently recognized, their migration and transformation, which are substantially affected by the microbial reduction process, remain unclear. In this study, hematite bioreduction and magnetite formation induced by Shewanella oneidensis MR-1, a typical metal-reducing bacterial strain, were investigated using an integrated approach that combined experiments and computational simulations at the molecular scale. High-resolution transmission electron microscopy coupled with selected area electron diffraction (SAED), Raman spectroscopy and magnetic property analyses confirmed the biogenic magnetite formation. The electron paramagnetic resonance (EPR) spectra show a decay of the EPR intensity with incubation time, implying that the biotransformation of hematite to magnetite led to concurrent changes in their contents and local structures. X-ray absorption fine spectroscopy (XAFS) identified a time-resolved structural evolution of Fe(II)/Fe(III) coordination. The octahedral configuration upon Fe(II) production was subsequently validated by DFT calculations. Microbial reductive dissolution provided various intermediate states and new chemical environments regarding Fe(II)/Fe(III) complexes, such as monodentate and bidentate coordination patterns. Bioreduction caused the breakage of iron–oxygen bonds in hematite and the concomitant formation of Fe complexing microstructures for biogenic magnetite production. All these findings reveal the underlying mechanisms for the biotransformation of Fe minerals at the molecular scale and may allow us to better understand the speciation, immobilization and bioavailability of hematite NPs in natural systems.
研究领域:
微生物学
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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
CHEMICAL GEOLOGY
·
2024
·
IF 3.6
Xinting Lü,Detao He,Yongsheng Liu,Ming Li,Jie Lin,Wei Chen,Lüyun Zhu,Ao Yang,Yantong Feng,Zhenyi Liu,Xianli Zeng,Zhaochu Hu
Iron oxide minerals, such as hematite and magnetite, are commonly found in a wide range of geological environments. Their Fe isotopic composition acts as a potent geochemical tracer, finding applications across various realms of Earth sciences. However, natural iron oxide minerals often have a high Cr content up to percentile levels, necessitating correction of isobaric interference caused by 54 Cr + on 54 Fe + to ensure accurate and precise in situ Fe isotopic compositions. In this study, a pure chromium metal with homogeneous isotopic compositions was examined within the analysis sequence to obtain the fractionation factor of Cr (β Cr ) for isobaric interference correction. A femtosecond laser ablation system combined with wet plasma conditions was used to decrease the matrix effect. We synthesized a series of magnetite and hematite samples with simple matrix as well as natural magnetite samples with complex matrix to evaluate the feasibility of Cr interference correction. By employing our proposed correction method, the deviation caused by the isobaric interference of 54 Cr + was effectively eliminated. The corrected δ 56 Fe values for hematite and magnetite samples, even with a Cr/Fe ratio of as high as 1.27, exhibited good agreement with the reference values within the long-term reproducibility uncertainty of 0.10‰. These results indicate the robustness of Cr interference correction in obtaining accurate Fe isotopic compositions of Cr-rich iron oxides.
研究领域:
地球化学
·
地质学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Peng Yi,Quan Chen,Hao Li,Di Lang,Qing Zhao,Bo Pan,Baoshan Xing
The formation and occurrence of environmentally persistent free radicals (EPFRs) have recently attracted increasing research attention. The interactions between organics and transition metals and the crystalline forms of the transition metals are essential for EPFR formation. This study is thus designed to investigate catechol degradation and compare the characteristics of EPFRs on α-Fe2O3 (hematite, HM) and α-FeOOH (goethite, GT). Catechol degradation was inhibited in the dark in the presence of iron oxides. The inhibition was stronger on GT-silica, but the electron paramagnetic resonance (EPR) signals of the two systems were comparable. The enhanced degradation under UV light irradiation was comparable between HM-silica and GT-silica, but the EPR signals were stronger on GT-silica. Catechol was adsorbed on HM in a mononuclear bidentate (M-B) configuration, but it was adsorbed in both mononuclear monodentate (M-M) and binuclear bidentate (B-B) configurations on GT. After series analysis, we proposed that the dimer-type radical (2,2′,3,3′-tetrahydroxy-1,1′-biphenylene) was responsible for the more stable EPR signals for the HM system, while the M-M structure was more favorable for the catechol stabilization. Note that in the analysis of EPFR formation mechanisms, it is important to consider (1) different crystalline lattices and (2) the contribution of the degradation byproducts of the parent organics.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Guangda Yu,Fenglian Fu,Chujia Ye,Bing Tang
The mobility of Cr(VI) in the environment is affected by the transformation of ferrihydrite (Fh) and ferrihydrite-humic acid co-precipitates (Fh-HA). However, the impacts of Fe(II)-induced transformation of Fh and Fh-HA on the mobility, speciation and partitioning of associated Cr(VI) remain unclear. In this study, the behaviors of adsorbed Cr(VI) during Fh and Fh-HA aging at 70 °C for 9 days (pH 0 = 3.0 and 7.0) in the absence and presence of Fe(II) were studied. Results revealed that the main speciation of Cr(VI) after transformation was non-desorbable Cr and its formation involved the following pathways. Firstly, Fe(II) (0.2 and 2.0 mM) induced the transformation of Fh-HA to hematite and goethite, promoting the structural incorporation of adsorbed Cr into hematite and goethite via complexation. Secondly, under neutral condition (pH 0 = 7.0), the low concentration of Fe(II) (0.2 mM) could not reduce completely Cr(VI) to Cr(III) and thus residual Cr(VI) was incorporated into the Cr(III)-Fe(III) co-precipitates. Thirdly, coprecipitated humic acid not only reduced Cr(VI) to Cr(III) via polysaccharide, but also formed complexes with incorporated Cr through carboxylic groups to sequester Cr. Our results demonstrate that Fe(II)-induced transformation of Fh-HA exerts major influences on associated Cr(VI) speciation and partitioning.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 48
·72764-72776
·
IF 5.19
Zhong Dan,Feng Weinan,Ma Wencheng,Liu Xinyue,Ma Jun,Zhou Ziyi,Du Xuan,He Fu
Goethite and lepidocrocite, as the main compositions of pipe deposits in the water distribution network, could be used as a catalyst for advanced oxidation processes (AOPs). This research utilizes them to activate PDS/H 2 O 2 and PMS/H 2 O 2 degrading the 2,4,6-trichlorophenol, respectively. To describe the incomplete degradation of pollutants and reflect the induction period, a modified first-order model has been proposed and used to analyze degradation differences under several key affecting factors. The results revealed that the PDS/H 2 O 2 system has a synergy effect in the 2,4,6-trichlorophenol degradation process. The possible degradation pathways and intermediate products were confirmed by gas chromatograph-mass spectrometry (GC–MS). The paper provides a new idea for the effective use of pipe deposits to remove chlorophenols from drinking water, which is of great significance to ensure water quality safety.
研究领域:
环境科学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）