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Showing papers on "Goethite published in 2021"


Journal ArticleDOI
TL;DR: A novel goethite/biochar composite was applied as peroxymonosulfate (PMS) activator for tetracycline (TC) degradation in the water to benefit the application of iron/ biochar materials in practical water treatment.

91 citations


Journal ArticleDOI
01 Feb 2021-Geoderma
TL;DR: In this paper, Zhao et al. analyzed the macroscopic adsorption behaviors and microscopic mechanisms of typical cations and oxyanions on three omnipresent iron (oxyhydr)oxides (i.e., ferrihydrite (Fh), goethite (Gt), and hematite (Hm)) in single-and double-solute systems.

80 citations


Journal ArticleDOI
15 Feb 2021-Fuel
TL;DR: In this paper, the availability of three natural iron ores for the catalytic reforming of volatiles from the co-pyrolysis of lignite and corn straw (CPLC) was investigated to study the influence of ore type and reaction temperature on product yield, tar composition as well as phase transformation of iron ore.

62 citations


Journal ArticleDOI
TL;DR: In this paper, the original Chang and Jackson (1957) method and a variant of it were used to detect discrete iron, aluminium and calcium phosphates in soil, even though none were present.
Abstract: Many soil scientists think that soil phosphate exists as discrete compounds of iron, aluminium and calcium and, accordingly, use chemical fractionation schemes to identify these compounds. We reacted a sample of goethite and a sample of aluminium oxide with a phosphate solution under conditions chosen to facilitate penetration of phosphate. Thus the sample of goethite had neither calcium nor aluminium present and similarly the sample of aluminium oxide had neither iron nor calcium. We included a sample of hydroxyapatite which had neither iron nor aluminium present. We subjected the samples to two fractionation procedures; the original Chang and Jackson (1957) method and a variant of it. For the phosphated goethite and aluminium oxide, energy dispersive X-ray spectra did not detect any discrete aluminium or iron phosphates; dissolution studies were consistent with penetration of phosphate. Both fractionation procedures detected discrete compounds even though none were present. They also detected iron, aluminium and calcium phosphates for samples for which they were not present. We also critically discuss other evidence for the existence of discrete iron, aluminium and calcium phosphates in soils. Fractionation procedures designed to measure chemically specified phosphate fractions in soil are fallacious and should be abandoned.

53 citations


Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate that the addition of ascorbate can lower the conversion percentage of H2O2 to O2 from 71% to 11%, and thus increase the conversion ratio from 11% to 82% on goethite within 3h.
Abstract: In this study, we demonstrate that the addition of ascorbate can lower the conversion percentage of H2O2 to O2 from 71% to 11%, and thus increase the conversion percentage of H2O2 to OH from 11% to 82% on goethite within 3 h. This greatly enhanced production of OH could be attributed to the efficient Fe(III)/Fe(II) redox cycle accelerated by ascorbate, which produced abundant Fe(II) confined on the goethite surface, favoring the conversion of H2O2 to OH. Meanwhile, the decreased surface Fe(III) of goethite strongly inhibited the conversion of H2O2 to O2. These findings can clarify the quantitative influence of ascorbate on the H2O2 decomposition process over the iron mineral surface, and thus deepen the understanding of heterogeneous Fenton reaction mechanism during organic containment treatment.

49 citations


Journal ArticleDOI
TL;DR: Electrochemical analysis, quenching experiments, and Fe species detection showed that the coprecipitated HA could serve as electron shuttle and complex with Fe( III) mainly via carboxyl groups at octahedral sites to improve Fe(III)/Fe(II) transformation.

45 citations


Journal ArticleDOI
TL;DR: In this article, the authors explored how native minerals and organic matter (OM) affect the rate of Fe(II) oxidation and resulting de novo Fe(III) minerals in soil slurries.

40 citations


Journal ArticleDOI
Min Yang1, Xiaohua Ren1, Leixin Hu1, Weilin Guo1, Jinhua Zhan2 
TL;DR: In this paper, two goethite materials with different contents of exposed {0,2,1} facet were synthesized and used as the catalysts for persulfate (PS) activation to degrade tetracycline.

39 citations


Journal ArticleDOI
TL;DR: Experimental results suggest that formation of inner-sphere complexes through the arsonic acid group is the primary mechanism for adsorption of p-ASA/ROX on iron (hydro)oxides and γ-MnO2, while outer-spheres complexation plays a critical role in their adsorbing on α-Al2O3 and kaolinite.

34 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the transformation kinetics and mechanism of tetracycline antibiotics with goethite to gain a better understanding of the fate of TCs in the natural environment.

31 citations


Journal ArticleDOI
TL;DR: In this article, the authors analyzed the geochemistry and mineralogy of a 46m-long sediment core drilled into the redox transition zone where a high As Holocene aquifer is juxtaposed to a low As Pleistocene Aquifer in the Red River delta, Vietnam.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the impact of antimony on the Fe-II-induced transformation of ferrihydrite at pH 7 across a range of Sb(V) loadings (Sb:Fe(III) molar ratios of 0, 0.016, and 0.08).
Abstract: The environmental mobility of antimony (Sb) is controlled by interactions with iron (Fe) oxides, such as ferrihydrite. Under near-neutral pH conditions, Fe(II) catalyzes the transformation of ferrihydrite to more stable phases, thereby potentially altering the partitioning and speciation of associated Sb. Although largely unexplored, Sb itself may also influence ferrihydrite transformation pathways. Here, we investigated the impact of Sb on the Fe(II)-induced transformation of ferrihydrite at pH 7 across a range of Sb(V) loadings (Sb:Fe(III) molar ratios of 0, 0.003, 0.016, and 0.08). At low and medium Sb loadings, Fe(II) induced rapid transformation of ferrihydrite to goethite, with some lepidocrocite forming as an intermediate phase. In contrast, the highest Sb:Fe(III) ratio inhibited lepidocrocite formation, decreased the extent of goethite formation, and instead resulted in substantial formation of feroxyhyte, a rarely reported FeOOH polymorph. At all Sb loadings, the transformation of ferrihydrite was paralleled by a decrease in aqueous and phosphate-extractable Sb concentrations. Extended X-ray absorption fine structure spectroscopy showed that this Sb immobilization was attributable to incorporation of Sb into Fe(III) octahedral sites of the neo-formed minerals. Our results suggest that Fe oxide transformation pathways in Sb-contaminated systems may strongly differ from the well-known pathways under Sb-free conditions.

Journal ArticleDOI
TL;DR: In this article, the effects of Ca on the thermal stability of organo-mineral associations in a synthetic mineral mixture of kaolinite, goethite, and aluminum (Al)-oxides mimicking the mineralogy of the clay-size fraction of weathered tropical soils were evaluated.

Journal ArticleDOI
TL;DR: In this paper, microwave-assisted reduction roasting of a goethite-rich, reject iron ore waste stream (−2 mm) was used to produce a high-grade concentrate.

Journal ArticleDOI
TL;DR: This study highlights the control of the uranyl mobility by various iron oxyhydroxides in supergene conditions by identifying uranyl ternary surface complexes at the ferrihydrite surface that were either composed of phosphate groups or organic matter.

Journal ArticleDOI
TL;DR: In this paper, the speciation of iron on crushed materials through spatially resolved micro-spectroscopic studies was analyzed by element-specific synchrotron-based techniques.

Journal ArticleDOI
TL;DR: Sequential extraction results showed that during the transformation of schwertmannite to goethite, most trace metals decreased their mobility by decreasing their exchangeable fraction, however, only Pb increased its mobility during transformation.

Journal ArticleDOI
TL;DR: In this article, the impact of goethite-modified biochar (GB) on bioavailability of both Cd and As in Cd- and As- polluted paddy soil was investigated.

Journal ArticleDOI
TL;DR: In this article, the role of organic electron shuttling compounds in determining arsenic cycling in soils was investigated, and it was shown that the addition of cysteine significantly enhances the oxidation efficiency of As(III) in the goethite/cysteine system.

Journal ArticleDOI
TL;DR: In this article, an anaerobic incubation study was conducted to investigate changes in CO2 emissions from organic C (SOC) and acetate (13C-labeleld) in response to iron oxide (ferrihydrite and goethite) addition in chloroform-fumigated and unfumigated paddy soils.
Abstract: In contrast to what is observed in aerobic uplands, microbial biomass and the presence of electron acceptors, such as iron oxides, play a crucial role in regulating soil organic C (SOC) mineralisation in paddy soils. However, the related underlying mechanisms are still poorly explored. We conducted an anaerobic incubation study to investigate changes in CO2 emissions from SOC and acetate (13C-labeleld) in response to iron oxide (ferrihydrite and goethite) addition in chloroform-fumigated and unfumigated paddy soils. The iron oxides, as electron acceptors, increased CO2 emissions from SOC with stronger impact under ferrihydrite than goethite addition. However, the acetate addition, as a preferable C source for reducing microbes, decreased SOC mineralisation and caused a negative priming effect. CO2 emission from both acetate and SOC was affected by microbial biomass change. In the acetate-treated soil, goethite in the fumigated soil (i.e. high microbial biomass) increased CO2 emissions from acetate, providing electron acceptors, and decreased CO2 emissions from SOC. Ferrihydrite accepted electrons and adsorbed acetate, resulting in a slight decline in CO2 emission from acetate. However, in the fumigated soil (i.e. low microbial biomass), both iron oxide additions reduced CO2 emissions from acetate and SOC and likely the dominant role of both iron oxides shifted from being electron acceptors to being adsorbents, thus limiting acetate accessibility to microorganisms. The results suggest that microbial biomass is a key driver in shifting the effects of iron oxides on organic C mineralisation in anaerobic paddy soils.

Journal ArticleDOI
TL;DR: In this article, the scandium speciation in bauxite residues of different origin was investigated using a combination of different analytical tools, such as laser ablation inductively coupled plasma mass spectrometry, X-ray absorption near edge structure (XANES) spectroscopy, μ-Raman and scanning electron microscopy and electron microprobe analyses.

Journal ArticleDOI
31 Jan 2021-Minerals
TL;DR: In this paper, the authors examined the effects of Fe(III) oxide mineralogy, phosphate concentration, and the availability of an electron shuttle (9,10-anthraquinone-2,6-disulfonate, AQDS) on the bioreduction of a series of Fe (III) oxides (akaganeite, feroxyhyte, ferric green rust, green rust and vivianite) by Shewanella putrefaciens CN32, and determined by X-ray diffraction, Mossbauer spectroscopy, and
Abstract: The bioreduction of Fe(III) oxides by dissimilatory iron-reducing bacteria may result in the formation of a suite of Fe(II)-bearing secondary minerals, including magnetite (a mixed Fe(II)/Fe(III) oxide), siderite (Fe(II) carbonate), vivianite (Fe(II) phosphate), chukanovite (ferrous hydroxy carbonate), and green rusts (mixed Fe(II)/Fe(III) hydroxides) In an effort to better understand the factors controlling the formation of specific Fe(II)-bearing secondary minerals, we examined the effects of Fe(III) oxide mineralogy, phosphate concentration, and the availability of an electron shuttle (9,10-anthraquinone-2,6-disulfonate, AQDS) on the bioreduction of a series of Fe(III) oxides (akaganeite, feroxyhyte, ferric green rust, ferrihydrite, goethite, hematite, and lepidocrocite) by Shewanella putrefaciens CN32, and the resulting formation of secondary minerals, as determined by X-ray diffraction, Mossbauer spectroscopy, and scanning electron microscopy The overall extent of Fe(II) production was highly dependent on the type of Fe(III) oxide provided With the exception of hematite, AQDS enhanced the rate of Fe(II) production; however, the presence of AQDS did not always lead to an increase in the overall extent of Fe(II) production and did not affect the types of Fe(II)-bearing secondary minerals that formed The effects of the presence of phosphate on the rate and extent of Fe(II) production were variable among the Fe(III) oxides, but in general, the highest loadings of phosphate resulted in decreased rates of Fe(II) production, but ultimately higher levels of Fe(II) than in the absence of phosphate In addition, phosphate concentration had a pronounced effect on the types of secondary minerals that formed; magnetite and chukanovite formed at phosphate concentrations of ≤1 mM (ferrihydrite), <~100 µM (lepidocrocite), 500 µM (feroxyhyte and ferric green rust), while green rust, or green rust and vivianite, formed at phosphate concentrations of 10 mM (ferrihydrite), ≥100 µM (lepidocrocite), and 5 mM (feroxyhyte and ferric green rust) These results further demonstrate that the bioreduction of Fe(III) oxides, and accompanying Fe(II)-bearing secondary mineral formation, is controlled by a complex interplay of mineralogical, geochemical, and microbiological factors

Journal ArticleDOI
Zhen Niu1, Gaibian Li, Dongdong He1, Xinzhuang Fu1, Wei Sun1, Tong Yue1 
TL;DR: Control of hydrothermal reaction temperature and acidity of the underflow solution can effectively avoid the generation of zinc/nickel/cobalt hydroxides or subsulfates in the hematite precipitates, thereby significantly reducing the loss of those valuable metals.

Journal ArticleDOI
TL;DR: In this article, a peerless inexpensive electrochemical engineering of spherical Pt nanoparticles was achieved with intersected ferric oxyhydroxide nanotubes (α-FeOOH (goethite): the FeOOH@Pt catalyst exhibited ca. 2.5 and 1.94-times increases in the catalytic activity and poisoning tolerance, respectively, of the formic acid electro−oxidation (FAO) reaction in the direct Formic acid fuel cells (DFAFCs).

Journal ArticleDOI
TL;DR: In this paper, the effects of utilizing goethite (5, 10, and 20%) in co-pyrolysis with low-lignin macroalgae, Saccharina japonica, on the carbon sequestration potential, magnetic, physicochemical, and dye (basic blue 41, BB41) removal properties of the resulting biochar were investigated.

Journal ArticleDOI
TL;DR: In this article, a new conversion method of goethite to nanorod erdite was investigated to develop an alternative route for reutilising Goethite-bearing waste.

Journal ArticleDOI
TL;DR: In this paper, an iron-carbon composites were prepared by co-pyrolysis of polyethylene (PE) and goethite (α-FeO(OH)) and used as a persulfate activator for catalytic oxidation of an azo dye chemical, amaranth.

Journal ArticleDOI
TL;DR: In this paper, 1,2,4-trichlorobenzene (124-TCB) was selected as a model compound to study its abatement using wet peroxide oxidation at neutral pH with goethite as a heterogeneous catalyst, which was enhanced with visible monochromatic light-emitting diode (LED) light.
Abstract: There is significant environmental concern about chlorinated organic compounds (COCs) in wastewater, surface water, and groundwater due to their low biodegradability and high persistence. In this work, 1,2,4-trichlorobenzene (124-TCB) was selected as a model compound to study its abatement using wet peroxide oxidation at neutral pH with goethite as a heterogeneous catalyst, which was enhanced with visible monochromatic light-emitting diode (LED) light (470 nm). A systematic study of the main operating variables (oxidant and catalyst concentration and irradiance) was accomplished to investigate their influence in the abatement of 124-TCB in water. The reaction was carried out in a well-mixed reactor of glass irradiated by a visible LED light. The hydrogen peroxide concentration was tested from 0 to 18 mM, the goethite concentration within the range 0.1–1.0 g·L−1 and the irradiance from 0.10 to 0.24 W·cm−2 at neutral pH. It was found that this oxidation method is a very efficient technique to abate 124-TCB, reaching a pollutant conversion of 0.9 when using 0.1 g·L−1 of goethite, 18 mM of H2O2, and 0.24 of W·cm−2. Moreover, the system performance was evaluated using the photonic efficiency (ratio of the moles of 124-TCB abated and the moles of photons arriving at the reactor window). The maximum photonic efficiencies were obtained using the lowest lamp powers and moderate to high catalyst loads.

Journal ArticleDOI
TL;DR: X-ray absorption and Mössbauer spectroscopies complemented by electron microscopy, and chemical extractions were used to examine vertical changes of As, Fe and S speciation for the example of sediments in the Hetao Basin to elucidate the complex relationship between biogeochemical processes and minerals formation in As contaminated aquifers.

Journal ArticleDOI
15 Aug 2021-Langmuir
TL;DR: In this article, the role of hydration microstructure and the adsorption mechanism of the flotation reagent on the oxide minerals on the goethite surface was investigated.
Abstract: Dodecylamine (DDA) and sodium oleate (OL) are commonly used collectors in the reverse flotation and the direct flotation of goethite. However, the flotation mechanisms of DDA and OL on the goethite surface remain unclear. In this study, the first-principles density functional theory calculations were used to reveal the role of the hydration of the goethite surface and its effects on flotation reagents from a microscopic perspective. The calculation results showed that DDA was adsorbed on the surface of goethite by hydrogen bonds in the absence of hydration. However, the existence of the hydration microstructure hindered the formation of hydrogen bonds and made it difficult for DDA to be adsorbed on the goethite surface. In the OL system, oleate ions are chemically adsorbed on the surface Fe sites of goethite in the absence of hydration, while in the presence of hydration, the oleate ions were adsorbed on the H-terminal hydration surface of goethite by hydrogen bonds. This work sheds new light on the roles of the hydration microstructure and the adsorption mechanism of the flotation reagent on the oxide minerals.