SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Xiaobo Gu,Wenhao Wu,Daohui Lin,Kun Yang
Soil is the largest terrestrial carbon pool, and adsorption of soil organic matter (SOM) by ferrihydrite is an essential geochemical process for preservation of organic carbon in soil. Freshly formed gel-like ferrihydrite and seasonally dried dense ferrihydrite are two typical morphologies of ferrihydrite in soil. However, the differences in SOM adsorption by gel-like ferrihydrite and dense ferrihydrite and the underlying mechanisms are unknown. In this study, adsorption of eight SOM or SOM-like compounds by gel-like ferrihydrite and dense ferrihydrite were compared. It was observed that the adsorption capacity of SOM by gel-like ferrihydrite (e.g., 304 mg C/g) was two orders of magnitude higher than that by dense ferrihydrite (e.g., 3.44 mg C/g). SOM adsorbed by the nanosized gel-like ferrihydrite could be mainly attributed to the heteroaggregation, confirmed by not only the TEM images but also the positive linear correlation between adsorption capacity and molecular weight of SOM. However, SOM adsorbed by the microsized dense ferrihydrite should be attributed to the pore-filling adsorption with molecular sieve effects, confirmed by the negative linear correlation between adsorption capacity and molecular weight of SOM. The obtained results could provide a new insight to understand the preservation of organic carbon by ferrihydrite in soil.
研究领域:
环境科学
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土壤学
·
地球化学
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Jiashun Cao,Weiyi Zhao,Suna Wang,Runze Xu,Liangshan Hao,Wei Sun
Phosphorus recovery by vivianite from different types of wastewater has attracted considerable attention recently. However, the existence of calcium (Ca) would unavoidably affect the formation of vivianite. In this work, the effect of calcium on vivianite crystallization was investigated. The pH of the solutions with low Ca concentration (1–10 mg/L) increased by only 0.06 compared to the conditions without Ca, while a more visible change occurred at high concentrations. Besides, higher removal rate of phosphorus was obtained at higher Ca concentration and the residual amount of Fe in the supernatant increased from 2.01 mg/L in control to 27.29 mg/L at 100 mg Ca/L, indicating competition between Ca and Fe ions. Furthermore, microscopic observation revealed that Ca caused the surface of vivianite to be covered by fine particles, resulting in the inhibition of vivianite growth. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated the fine particles covering in the surface of vivianite crystals were mainly amorphous Ca 3 (PO 4 ) 2 and the formation of Fe-phosphate (s) also led to the decrease of the recovery rate and purity of vivianite. The zeta potential of the recovered product indicated that electrostatic adsorption existed in the process and complemented with surface adsorption to become the main routes of Ca binding. The results obtained herein will provide a theoretical basis for understanding the interference of calcium with vivianite crystallization.
研究领域:
环境科学
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废水处理
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产品关联
DOI
高影响因子
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
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2024
·Vol. 129
·期 4
·e2023JE008031
·
IF 3.9
Xinyi Xiang,Peixin Du,Binlong Ye,Hongling Bu,Dong Liu,Jiacheng Liu,Jian Hua,Xiaolong Guo
Ferrihydrite, a nanocrystalline iron (oxyhydr)oxide mineral, is widely distributed in soils and sediments on Earth and is probably an important component and/or precursor of widespread nanophase iron minerals on Mars. Terrestrial ferrihydrite often co-occurs with amorphous silica and/or contains a certain amount of Si in its structure. However, it remains ambiguous how environmental Si concentration affects the formation-evolution and structure-spectral features of ferrihydrite in the Fe(III)-Si systems. To this end, hydrolysis experiments were carried out for Fe-Si systems at an unprecedentedly wide range of initial Si/(Fe + Si) molar ratios (0–0.80), followed by characterizing the products detailly. X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, Mössbauer spectroscopy, and transmission electron microscopy results showed that at Si/(Fe + Si) molar ratios ≤0.30, the main phase of the products was ferrihydrite, of which the unit cells enlarged, the crystallinity decreased, and the existing state of Fe changed with increased Si contents; at Si/(Fe + Si) molar ratios ≥0.40, ferrihydrite was no longer formed and a novel amorphous Fe-O-Si phase was instead obtained, with the excess Si forming amorphous silica. The visible and near-infrared spectroscopy, the most powerful tool to detect hydrous minerals on the surface of Mars at global or regional scales, showed weakness in identifying ferrihydrite-like materials obtained in the Fe-Si systems. Raman spectroscopy can identify ferrihydrite and Si-containing ferrihydrite but cannot differentiate between them. Mössbauer spectroscopy showed great potential in both identifying and differentiating between ferrihydrite and Si-containing ferrihydrite, and thus can be used to characterize the poorly ordered iron (oxyhydr)oxides on Mars. Key Points Hydrolysis experiments of Fe(III)-Si systems were performed at an unprecedentedly wide range of initial Si/(Fe + Si) molar ratios (0∼0.80) The environmental Si concentration controls the formation and evolution of ferrihydrite in the Fe(III)-Si systems Mössbauer spectroscopy shows great potential in identifying and differentiating between ferrihydrite-like materials Plain Language Summary On the surface of ancient Mars where liquid water was available, Fe-Si hydrolysis systems were likely common as a result of the high abundances of Fe and Si in the crust of Mars. By performing hydrolysis experiments of Fe-Si systems at an unprecedented wide range of Si/(Fe + Si) molar ratios, we found that the hydrolysis products of Fe-Si systems varied among combinations of ferrihydrite, Si-containing ferrihydrite, an unknown Fe-O-Si phase, and amorphous silica. We also found that the visible and near-infrared reflectance spectroscopy, the most powerful tool to remotely detect hydrous minerals on the surface of Mars at global and regional scales, showed weakness in identifying ferrihydrite, Si-containing ferrihydrite, and the novel Fe-O-Si phase; Raman can be used to identify ferrihydrite-like materials but cannot be used to differentiate between ferrihydrite and Si-containing ferrihydrite; mid-infrared spectroscopy can differentiate ferrihydrite from Si-containing ferrihydrite and the novel Fe-O-Si phase; Mössbauer spectroscopy (recorded at varied temperatures) provided clues to identifying and further differentiating between ferrihydrite-like materials and thus holds great potential for detecting Fe/Si-rich phases on the surface of Mars.
研究领域:
地质学
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行星科学
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矿物学
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DOI
高影响因子
Agriculture-Basel
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2024
·Vol. 14
·期 3
·450
·
IF 3.3
Lijuan Li,Xinyi Chen,Yan Wang,Fubin Zhang,Xinyi Zhou,Tuo Zhang
Ferrihydrite is usually used as a remedy for arsenic (As)-contaminated soil due to its strong affinity and large specific surface area. However, its noncrystalline phase makes it unstable in long-term applications in the soil. In this study, a soil incubation experiment was designed using the diffusive gradient in thin film (DGT) technique and spectral techniques to investigate the fate of As-bearing ferrihydrite [As(V)-Fh] after long-term incubation at different soil water holding capacities (SWHCs). After As(V)-Fh (0.05 and 0.005 As/Fe molar ratio) was incubated in soil for 360 days, both DGT-derived labile As and Fe were released at 70% SWHC and 120% SWHC into the soil (at a vertical depth of 12 cm). The concentrations of DGT-As and DGT-Fe increased with incubation time and were greater at 120% SWHC. The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that As(V)-Fh gradually transformed into hematite and goethite after 360 days of incubation. Goethite was mainly found in the 120% SWHC treatment after 180 days. Hematite and goethite formation rates were greater in the 120% SWHC treatment and in the bottom soil layer. Mechanistic analysis based on X-ray photoelectron spectroscopy (XPS) revealed that the variation in soil pH and the formation of Fe(II) (under flooded water conditions) are the two key factors promoting the formation of hematite (dehydrogenation and dehydration) and goethite (As(V)-Fh dissociation and reorganization). The As release mainly occurred due to the loss of adsorption sites. Thus, it is recommended that ferrihydrite be applied in paddy–dry rotations or dry-field patterns to effectively avoid the loss of As(V)-Fh in long-term-saturated soil.
研究领域:
环境科学
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土壤学
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DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Tuo Zhang,Xinyi Chen,Yu Wang,Lijuan Li,Yuanyuan Sun,Yanan Wang,Xibai Zeng
2- Line ferrihydrite (Fh) is widely used as a robust amendment for rapid arsenic removal or remediation in water or soil. However, the poorly crystalline phase of Fh is unstable and leads to arsenic leaching after long-term submergence in reductive aquatic and soil environments. In this study, the synthesized As(V)-bound Fh was characterized by various spectral approaches to investigate the factors that may affect the variation in As(V)-Fh in long-term continuously submerged soil suspensions. The X-ray diffraction (XRD) results showed that hematite was the main product and that goethite was the byproduct after 360 d of incubation. Approximately 12–17% and 4–5% Fh were transformed at As/Fe mole ratios of 0.005 and 0.05, respectively. After 360 d of incubation, the hematite morphology was clearly observed by scanning electron microscopy (SEM), and the As(V)-Fh surface areas were also decreased by 17.3–27.6% and 11.9–16.6% for As/Fe mole ratios of 0.005 and 0.05, respectively. In a comparison of the two tested soils (soils sampled in Sichuan Province (SC) and Hunan Province (HN)), As(V)-Fh transformed faster in HN soil suspensions, and more hematite and goethite were formed. Furthermore, during the incubation period, As(V) was transformed to As(III), and both species were released into the suspension from the As(V)-Fh surface. It was suggested that soil pH and Fe(II) concentration were key factors controlling the As(V)-Fh transformation process, and the differences between the two soils were due to the different soil pH values and contents of available Fe. Arsenic release was mainly caused by Fh transformation and ligand competition with soil organic matter (SOM).
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2021
·
IF 6.789
Mengjie Wang,Qiang Zhang,Taotao Lu,Jiuyan Chen,Qiqi Wei,Weifeng Chen,Yanmei Zhou,Zhichong Qi
Given the ubiquitous mineral (e.g., clays and iron oxides) playing critical roles in impacting the fate of antibiotics in the subsurface environment, the effects of two mineral colloids (i.e., ferrihydrite and montmorillonite) on tetracycline (TC, a representative of antibiotic) transport in sand columns were investigated in this study. Interestingly, the results clearly showed that ferrihydrite colloids inhibited TC transport, while montmorillonite colloids enhanced TC mobility under neutral conditions (pH 7.0). This phenomenon resulted from the positively charged ferrihydrite colloids with weak mobility, which assisted TC deposition; besides, providing additional deposition sites for TC by the deposited ferrihydrite colloids was another important mechanism. In contrast, the transport-enhancement effect of montmorillonite on TC was attributed to the strong binding affinity of TC to clay particles as well as the competition between colloids and TC for deposition sites on sand surfaces. Moreover, the transport-inhibition effect of ferrihydrite at pH 7.0 was greater than that at pH 5.0, mainly due to more colloid-associated TC under neutral conditions. Surprisingly, ferrihydrite colloids could act as carriers of antibiotics and enhanced TC transport at pH 9.0. Because the surface charge of colloids was altered to negative and could break through the column. Meanwhile, the transport-enhancement effect of montmorillonite decreased with increasing pH from 5.0 to 9.0, resulting from the decrease of colloid-adsorbed TC. Furthermore, colloid-mediated transport of TC was influenced by ionic strength , which affected the aggregation characteristics of colloids and the binding affinities of TC to minerals. These findings provide critical information for assessing the risks of antibiotics in aquatic ecosystems where abundant natural minerals are present.
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
·
2021
·
IF 7.312
Wei Zhang,Qiao Li,Rui Li,Nan Shen,Jiansheng Li,Jinyou Shen,Xiuyun Sun,Weiqing Han
Industrial wastewater containing organic ligands and heavy metals is considered a serious public health threat, and its treatment and purification have become challenging tasks. Moreover, the organic-chelated heavy metals formed by common organic ligands and free heavy metals can cause many problems and concerns because of their poor biodegradability, high solubility, and extreme stability. In this study, aluminum-containing ferrihydrite (Fh-Al) adsorbents of different composition molar ratios were prepared and utilized to remove typical EDTA-Cr(III) in an aqueous system, and the associated removal mechanism was examined. The experimental results show that adding Al not only enhances the removal rate of EDTA-Cr(III) by the Fh-Al adsorbent in a wide pH range (pH = 3–9) but also increases the maximum adsorption capacity of EDTA-Cr(III). In addition, the specific surface area of Fh-Al can be increased by adding aluminum with different molar ratios, thus promoting its adsorption performance for EDTA-Cr(III). Furthermore, surface complexation and electrostatic attraction were proposed as possible mechanisms of EDTA-Cr(III) adsorption by Fh-Al. This study shows that Fh-Al-6 adsorbent can adsorb common EDTA-chelated heavy metals (such as EDTA-Pb, EDTA-Cr, EDTA-Cu and EDTA-Cd) in one step, with maximum adsorption capacities of 41.47, 32.33, 16.51 and 31.27 mg/g at pH = 3. The Fh-Al-6 adsorbent can be reused after being regenerated in a 2 g/L Na 2 SO 4 solution. This study provides new expectations for treating wastewater containing organic groups and heavy metals.
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
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Miao Jiang,Kun Wang,Gen Li,Qingliang Zhao,Weiye Wang,Junqiu Jiang,Yipeng Wang,Luzi Yuan
Co-contamination of As, Sb, and Pb in soil has aroused public concern due to their wide application in industries. However, the efficient stabilization materials with simultaneous cations and anions stabilization capacities are still lacking and remain a challenge. Herein, a new type of montmorillonite modified by amorphous ferrihydrite ( [email protected] ) was synthesized and the immobilization performance of [email protected] for As, Sb, and Pb in soil was investigated comprehensively, mainly by TCLP, SBET, and DTPA extraction. The stabilization efficiency assessed by TCLP reached 86.28 % for Sb and 94.60 % for Pb after 56 days, and the As could not be detected in the leachate after 10 days. For As, Sb and Pb, the SBET method achieved a reduction of 87.34 %, 54.59 % and 17.59 % respectively. The DTPA extractable content of the metal(loid)s also declined significantly, especially for As. By applying [email protected] , the soil properties as well as the bacterial richness and diversity in the soil were obviously improved. The [email protected] adsorption data are well fitted to the Langmuir model and the pseudo-second-order model. The principal stabilization mechanisms were ascribed to inner-sphere complexation, surface precipitation and co-precipitation, and structural incorporation into [email protected] This is the first study to exhibit the feasibility of [email protected] as an effective and environmentally friendly stabilizer for remediation of As/Sb/Pb co-contaminated soils.
研究领域:
环境科学
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土壤修复
·
地球化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Wang-Xiao Jia,Wen-Qiang Li,Zhi-Hui Xie,Pu-Can Guo,Zhi-Long Ye,Zhao-Kun Xiong,Chuan-Shu He,Bo Lai
Formation of vivianite is a promising strategy to recover phosphorus from urban sewage and livestock wastewater, in which both various antibiotics and dissolved organic matters are contained. In this study, the interaction relationship and mechanism between vivianite, antibiotics and DOM were analyzed through the variations of DOM and antibiotics concentrations in supernatant, combined with characterization analysis and theoretical calculation. It’s found that the adsorption of three kinds of antibiotics onto vivianite following the order: tetracycline (TC) (∼90%) > ciprofloxacin (CIP) (∼15%) > sulfamethoxazole (SMX) (∼5%). The presence of fulvic acid (FA) greatly enhanced the adsorption of CIP, SMX to about 90%, 17% respectively, while there was no significant change in the adsorption of TC probably due to its good adsorption in the absence of FA. Interestingly, further analysis demonstrated that the FA will enhance the adsorption of antibiotics to vivianite because of the non-bonding interaction between FA molecules adsorbed on the surface of vivianite and antibiotics, and make the vivianite form better crystal without significant influences on phosphorus recovery. In addition, this study found that the adsorption of different kinds of antibiotics by vivianite was significantly related to the molecular weight of dissolved organic matter (DOM) in the actual livestock wastewater. Interestingly, the promotion of SMX adsorption is more likely to occur in the presence of DOM with small molecular weight (<5 kDa), while the introduction of DOM with larger molecular weight has greater promotion effect on CIP adsorption. The results gained in this study will expand the knowledge about the fate of antibiotics and recovery of phosphorus from urban sewage and livestock wastewater in the formation of vivianite.
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Ziyan Zhou,Dingding Wu,Hao Wu,Boming Fu,Xinhao Wang,Jingyi Ling,Xin Jin,Cheng Gu
Sertraline is one of the most commonly used antidepressant pharmaceuticals with ubiquitous distribution in the aqueous environment. However, the environmental behavior of sertraline in the co-presence of low-molecular-weight organic acid (LMWOA) and iron oxide mineral is still poorly understood. In this study, the photodegradation of sertraline was systematically investigated in a common photosensitizing system (ferrihydrite (Fh)-LMWOA). Six LMWOAs, including citrate acid (CA), tartrate acid (TA), malate acid (MA), lactate acid (LA), succinate acid (SA) and malonic acid (MOA) were chosen as the representatives. Our results implied that the different Fe 3+ dissolution rates would lead to rather different sertraline degradation patterns following the order of Fh-CA > Fh-TA > Fh-MA > Fh-LA > Fh-SA > Fh-MOA. The reaction was initiated by the interaction between LMWOA and Fh via ligand-promoted-dissolution mechanism. Furthermore, the Fe 3+ dissolution rates also showed a strong correlation with the metal-organic complexation constants, indicating that the photodegradation process is strongly related to the complexation ability of LMWOA with Fe 3+ . •OH, O 2 •- and CO 2 •- were detected, indicating that they contributed to the photodegradation of sertraline. •OH was demonstrated to be the dominant Reactive oxygen species (ROS) for the degradation of sertraline, and the detailed transformation pathways were proposed based on the product analysis and theoretical calculation. According to the ecological structure activity relationship estimation, the photodegradation products of sertraline possessed lower toxicity compared to the parent compound. These findings contribute to a more comprehensive understanding of the environmental fate of sertraline and evaluate its potential ecotoxicity in natural systems.
研究领域:
环境科学
·
化学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2013
·
IF 3.258
Yan Xu,Yan He,Xiaoli Feng,Luyi Liang,Jianming Xu,Philip C. Brookes,Jianjun Wu
A novel Fe(III) reducing bacterium, Clostridium beijerinckii Z, was isolated from glucose amended paddy slurries, and shown to dechlorinate pentachlorophenol (PCP). Fifty percent of added PCP was removed by C. beijerinckii Z alone, which increased to 83% in the presence of both C. beijerinckii Z and ferrihydrite after 11 days of incubation. Without C. beijerinckii Z, the surface-bound Fe(II) also abiotically dechlorinated more than 40% of the added PCP. This indicated that the biotic dechlorination by C. beijerinckii Z is a dominant process causing PCP transformation through anaerobic dechlorination, and that the dechlorination rates can be accelerated by simultaneous reduction of Fe(III). A biochemical electron transfer coupling process between sorbed Fe(II) produced by C. beijerinckii Z and reductive dehalogenation is a possible mechanism. This finding increases our knowledge of the role of Fe(III) reducing genera of Clostridium in dechlorinating halogenated organic pollutants, such as PCP, in anaerobic paddy soils.
研究领域:
环境微生物学
·
生物修复
·
土壤科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Jinlong Yan,Xiangqian Zhou,Wei Zhang,Fengli Cheng,Hui Wang,Liqiang Cui,Guixiang Quan
Dissolved organic matter from biochar (BDOM) inevitably integrates into the geochemical cycle throughout the remediation process. However, the binding mechanisms of BDOM onto various soil minerals, as well as the efficacy of phosphorus removal, remain inadequately understood. In this study, the formation and mechanism of montmorillonite-BDOM, ferrihydrite-BDOM, and goethite-BDOM complexes (referred to as MB, FB, and GB, respectively) were investigated and their structural morphology was analyzed using characterization methods such as BET, SEM, XRD, and FT-IR. Results indicated that FB had the largest specific surface area (SSA, 225.63 m 2 /g) and its adsorption was primarily governed by ligand exchange (58.51–76.47 %), whereas van der Waals forces predominated in the adsorption by montmorillonite (60.69–67.22 %). Batch tests showed that the adsorption properties of phosphorus were influenced by SSA and porosity of the complexes, which were FB > ferrihydrite > goethite > GB > MB > montmorillonite. The R 2 of pseudo-second-order kinetics (0.802–0.994) and Freundlich adsorption isotherm (0.970–0.980) for minerals and complexes to phosphorus fit better compared to pseudo-first-order kinetics (0.632–0.979) and Langmuir isotherm (0.798–0.966). The effect of environmental conditions on adsorption was also studied, showing that a slightly lower pH favored minerals and complexes other than montmorillonite and MB, with citric acid promoting FB adsorption by 18.68 % (16.34 mg/g) over the control, whereas oxalic acid was more favorable for MB adsorption, with a 41.16 % increase (3.60 mg/g). This study underscores the importance of the mineral adsorption-binding BDOM process and provides valuable insights into the transport and transformation of phosphorus in the natural environment.
研究领域:
土壤科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）