ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 21
·17598-17605
·
IF 2.741
Wang Na,Jia Daqing,Jin Yaoyao,Sun Sheng-Peng,Ke Qiang
The present study investigated the degradation of trichloroethylene (TCE) in sand suspensions by Fenton-like reaction with magnetite (Fe 3 O 4 ) in the presence of various chelators at circumneutral pH. The results showed that ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) greatly improved the rate of TCE degradation, while [S,S]-ethylenediaminedisuccinic acid (s,s-EDDS), malonate, citrate, and phytic acid (IP6) have minimal effects on TCE degradation. Quenching tests suggested that TCE was mainly degraded by hydroxyl radical (HO · ) attack, with about 90% inhibition on TCE degradation by the addition of HO · scavenger 2-propanol. The presence of 0.1–0.5% Fe 3 O 4 /sand ( w / w ) contributed to 40% increase in TCE degradation rates. In particular, the use of chelators can avoid high concentrations of H 2 O 2 required for the Fenton-like reaction with Fe 3 O 4 , and moreover improve the stoichiometric efficiencies of TCE degradation to H 2 O 2 consumption. The suitable concentrations of chelators (EDTA and NTA) and H 2 O 2 were suggested to be 0.5 and 20 mM, respectively. Under the given conditions, degradation rate constants of TCE were obtained at 0.360 h −1 with EDTA and 0.526 h −1 with NTA, respectively. Enhanced degradation of TCE and decreased usage of H 2 O 2 in this investigation suggested that Fenton-like reaction of Fe 3 O 4 together with NTA (or EDTA) may be a promising process for remediation of TCE-contaminated groundwater.
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
PubMed
高影响因子
Minerals
·
2019
·Vol. 10
·期 1
·24
·
IF 2.25
Pengfei Hu,Long Liang,Yaoli Peng,Hesheng Yu,Guangyuan Xie
Efficient beneficiation of microcrystalline graphite remains a challenge. Selective recovery of microcrystalline graphite from quartz using hydrophobized magnetite as magnetic seed is studied in this work. Magnetite was hydrophobized by the surface coating of sodium oleate. The hydrophobic agglomerates were then separated by magnetic separation. Sedimentation experiments were performed to study the adhesion of microcrystalline graphite and quartz to magnetite particles. The results showed that hydrophobized magnetite led to a higher microcrystalline graphite recovery than that of the original magnetite, due to the higher probability to bond with microcrystalline graphite. However, the hydrophobization of the magnetite surface had an insignificant effect on its interaction with quartz. The force analysis based on the extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) theory indicated that the total attractive interaction between hydrophobized magnetite and microcrystalline graphite were obviously stronger than that between hydrophobized magnetite and quartz, resulting in the selective aggregation between hydrophobized magnetite and microcrystalline graphite.Keywords:microcrystalline graphite;hydrophobized magnetite;magnetic seeding;aggregation
研究领域:
矿物加工工程
·
材料科学
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DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2023
·
IF 6.1
Yongkui Li,Xianjin Qi,Guohua Li,Heng Wang,Guizhi Yan,Jiahao Shi
As-containing acidic wastewater from the nonferrous heavy smelting industry is a hazardous As pollution source due to its complex composition, high acidity, and strong toxicity. In this study, an environmentally friendly strategy was proposed to simultaneously remove and immobilize As from acidic wastewater through the synthesis of highly stable scorodite using natural magnetite ore as Fe resource. Firstly, the magnetite ore was dissolved in wastewater to provide a certain amount of starting Fe source for the subsequent arsenic precipitation while creating a suitable pH environment for the synthesis of scorodite. Subsequently, the released Fe ions reacted with As ions in wastewater with undissolved magnetite ore as the nuclear site to form amorphous ferric arsenate, which was then transformed into a well-crystallized scorodite precipitate, thus achieving the As removal and immobilization. Under the optimal reaction conditions, including a Fe/As molar ratio of 2.5, a pre-dissolution time of 5 h, an initial pH of 2.0, a reaction time of 24 h, and a reaction temperature of 90 °C, the residual As concentration in the wastewater rapidly reduced from initial 6259.00 mg/L to 3.76 mg/L, corresponding to an arsenic removal efficiency of 99.94%, and the leaching As concentration in scorodite was 0.42 mg/L. This study provides an efficient and environmentally friendly method for the disposal of high As-containing wastewater from nonferrous smelting.
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
CHEMOSPHERE
·
2021
·
IF 7.086
Dan Wu,Hongshuai Kan,Ying Zhang,Tiecheng Wang,Guangzhou Qu,Peng Zhang,Hanzhong Jia,Hongwen Sun
Polycyclic aromatic hydrocarbons (PAHs) are important mutagen prevalent in the contaminated sites, bringing potential risks to human health. Iron oxides are important natural components in soils. Pyrene removal in soil using persulfate (PS) oxidation activated by microwave (MW) and magnetite (Fe 3 O 4 ) was investigated. Fe 3 O 4 significantly promoted pyrene removal in the soil; 91.7 % of pyrene was degraded within 45 min treatment. Pyrene removal rate in the Fe 3 O 4 /MW/PS system was 5.18 and 3.00 times higher than that in the Fe 3 O 4 /PS and MW/PS systems. Increasing in Fe 3 O 4 dosage, PS concentration, MW temperature, and soil moisture content in the selected range were conducive for pyrene degradation. SO 4 •− , • OH, O 2 •− , and 1 O 2 were responsible for pyrene degradation, and the conversion of Fe (Ⅱ) in the Fe 3 O 4 to Fe (Ⅲ) contributed to the formation of O 2 •− and 1 O 2 . Characteristic bands of pyrene were more obviously destroyed by the Fe 3 O 4 /MW/PS oxidation, in comparison with MW/PS oxidation. Ring hydroxylation and ring-opening reactions were the main degradation pathways of pyrene. The toxicities of the formed byproducts were significantly reduced after treatment. This study provided a promising option for pyrene contaminated soil remediation .
研究领域:
环境科学
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污染治理
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DOI
高影响因子
MINERALS ENGINEERING
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2021
·
IF 4.765
An Liu,Pan-pan Fan,Feng Han,Hua Han,Zhi-hong Li,Huai-fa Wang,Min-qiang Fan
In this study, the electroflotation of quartz and magnetite with cationic collector dodecylamine (DDA) and anionic collector sodium oleate (NaOL) were investigated to gain a better understanding of the electroflotation process and identify methods to improve it. An interesting phenomenon accompanied with obvious promotion (NaOL is used as collector) and inhibition (DDA-HCl is used as collector) of quartz flotation was observed after electrolysis. The obvious promotion arouse from the supply of the metal cations as active site for the adsorption of negatively charged group and increase active collecting species ionic forms RCOO - and (RCOO) 2 2– . Conversely, the obvious inhibition originated from the decrease of the active collecting species RNH 3 + and (RNH 3 ) 2 2+ . An obvious inhibition phenomenon was observed after the electrolysis for the magnetite. This is because the active collecting species RNH 3 + , (RNH 3 ) 2 2+ , RNH 2 ·RNH 3 + and RCOOH molecule decreased significantly after electrolysis. Furthermore, a comparison test between the regular flotation and electroflotation was conducted in the reverse flotation of magnetic separation concentrate. Compared with the regular flotation process, electroflotation flotation was characterized by simple reagent regime (without pH regulator and activator) and moderate conditions (natural pH), which had mild operation condition superiority. Moreover, the flotation product index of electroflotation can be better through slightly adjusting the reagent regime, and it can be certain that electroflotation is an effective process in the reverse flotation of magnetite. These findings provided a novel perspective for understanding the electroflotation process.
研究领域:
矿物加工工程
·
浮选化学
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DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 20
·7156
·
IF 3.748
Huimei Shan,Yunquan Liu,Chunya Zeng,Sanxi Peng,Hongbin Zhan
A magnetite graphene oxide chitosan (MGOCS) composite microsphere was specifically prepared to efficiently adsorb As(III) from aqueous solutions. The characterization analysis of BET, XRD, VSM, TG, FTIR, XPS, and SEM-EDS was used to identify the characteristics and adsorption mechanism. Batch experiments were carried out to determine the effects of the operational parameters and to evaluate the adsorption kinetic and equilibrium isotherm. The results show that the MGOCS composite microsphere with a particle size of about 1.5 mm can be prepared by a straightforward method of dropping FeCl2, graphene oxide (GO), and chitosan (CS) mixtures into NaOH solutions and then drying the mixed solutions at 45 °C. The produced MGOCS had a strong thermal stability with a mass loss of <30% below 620 °C. The specific surface area and saturation magnetization of the produced MGOCS was 66.85 m2/g and 24.35 emu/g, respectively. The As(III) adsorption capacity (Qe) and removal efficiency (Re) was only 0.25 mg/g and 5.81% for GOCS, respectively. After 0.08 mol of Fe3O4modification, more than 53% of As(III) was efficiently removed by the formed MGOCS from aqueous solutions over a wide pH range of 5–10, and this was almost unaffected by temperature. The coexisting ion of PO43−decreasedQefrom 3.81 mg/g to 1.32 mg/g, but Mn2+increasedQefrom 3.50 mg/g to 4.19 mg/g. The As(III) adsorption fitted the best to the pseudo-second-order kinetic model, and the maximumQewas 20.72 mg/g as fitted by the Sips model. After four times regeneration, theRevalue of As(III) slightly decreased from 76.2% to 73.8%, and no secondary pollution of Fe happened. Chemisorption is the major mechanism for As(III) adsorption, and As(III) was adsorbed on the surface and interior of the MGOCS, while the adsorbed As(III) was partially oxidized to As(V) accompanied by the reduction of Fe(III) to Fe(II). The produced As(V) was further adsorbed through ligand exchange (by forming Fe–O–As complexes) and electrostatic attraction, enhancing the As(III) removal. As an easily prepared and environmental-friendly composite, MGOCS not only greatly adsorbs As(III) but also effectively removes Cr(VI) and As(V) (Re> 60%) and other metals, showing a great advantage in the treatment of heavy metal-contaminated water.Keywords:chitosan;graphene oxide;magnetite;As(III) removal
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
Metals
·
2022
·Vol. 12
·期 6
·1019
·
IF 2.695
Shushi Zhang,Peng Hu,Jiating Rao,Zhenyang Wang,Yanbing Zong,Jianliang Zhang
HIsmelt is well suited for smelting vanadium–titanium magnetite due to its flexibility in feedstock selection and tolerance to high viscosity slag, compared with the blast furnace. In this work, the effect of smelting time on the distribution behavior and recovery rates of vanadium and titanium in HIsmelt smelting of vanadium–titanium magnetite was investigated by experiment for the first time. The relationship between slag viscosity and temperature at different smelting times was further revealed by thermodynamic calculations. The experimental results show that extending the smelting time increases the FeO content in the slag, theLVrose from 0.66 to 5.02, theLTideclined from 206.90 to 114.86, the shorter smelting time is favorable for increasing the recovery ratio of vanadium and titanium in metal and slag. In addition, slag viscosity decreases with increasing smelting time. The precipitation of high melting point titania spinel and CaTiO3phases is responsible for the significant increase in slag viscosity at 1300 °C.Keywords:HIsmelt;vanadium titano–magnetite;distribution behavior;recovery;viscosity
研究领域:
冶金学
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材料科学
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DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2024
·
IF 4.5
Huiping Zeng,Xiao Sun,Siqi Sun,Weihua Zhao,Ruixia Hao,Jie Zhang,Dong Li
Combining natural polymer starch with magnetite nanoparticles (MNPs) can reduce the aggregation of MNPs and enhance their adsorption capacity and stability. Iron sludge from a de‑ironing water plant and starch were employed as basic ingredients in this study. Bare magnetite nanoparticles (MNPs) and starch-coated magnetite nanocomposites (ST 2 -MNPs) were synthesized by a “green” co-precipitation method for the removal of low-concentration As(V) solutions. TEM, XPS, FTIR, XRD, VSM, BET, and TGA techniques were used to examine the physicochemical properties of the synthesized ST 2 -MNPs. TEM verified that the magnetite nanoparticles in the composites were evenly distributed. The ST 2 -MNPs (5.26 nm) possessed a smaller average particle size than MNPs (6.24 nm). And VSM confirmed their remarkable magnetic properties. The starch-to‑iron-sludge ratio was optimized and the influence of adsorbent dosage, pH, and co-existing anions on As(V) adsorption were studied. The acquired arsenate adsorption data were found to be consistent with the Langmuir isotherm model, with maximum adsorption capacities of 23.04 mg/g for MNPs and 42.88 mg/g for ST 2 -MNPs. This shows that the active sites on MNPs and ST 2 -MNPs are energetically homogenous, and that the addition of starch coating significantly increases magnetite's adsorption capacity for As(V). The adsorption kinetics follow a Pseudo-second-order kinetic model, indicating chemisorption between As(V) and ST 2 -MNPs. In addition, the adsorption mechanism of As(V) by ST 2 -MNPs including chemical adsorption and electrostatic attraction was determined through in-depth discussion of characterization methods and adsorption experiments. This study offers references for the removal of As(V) and the resourceful application of backwash iron sludge.
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
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Liang Chen,Zhenghao Wang,Xinyang He,Gang Zhi,Kailong Zhang,Liping Cao,Dongmei Luo,Bin Liang
The pursuit of efficient hydrogen production has driven the development of chemical looping hydrogen generation (CLHG), a promising technology that converts low–calorific–value reducing gases into high–purity hydrogen with minimal environmental impact. However, the limited activity and high cost of oxygen carriers (OCs) have hindered the broader adoption of CLHG. In this study, efficient and low–cost magnetite–based OCs were developed through pre-oxidation and transition metal modification. The results showed that pre–oxidation of magnetite at 900 °C for 2 h significantly increased oxygen vacancy concentration and porosity, boosting hydrogen yield from 0.64 mmol‧g −1 to 3.65 mmol‧g −1 . Further modification with nickel led to a twelvefold enhancement in hydrogen production, achieving 7.60 mmol‧g −1 at 650 °C. Notably, the purity of generated hydrogen exceeded 99.50 % without additional separation procedures. This study also identified sintering as a primary deactivation mechanism, which can be mitigated with an oxygen–assisted regeneration strategy. These findings offer valuable insights for developing efficient OCs and high–purity hydrogen generation from industrial off–gas.
研究领域:
能源材料科学
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化学工程
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产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2024
·
IF 9.9
Xiaobo Guo,Ao Xia,Feng Li,Yun Huang,Xianqing Zhu,Wuyuan Zhang,Xun Zhu,Qiang Liao
The integration of photoenzymatic decarboxylation and anaerobic digestion (AD) to convert food waste into hydrocarbon was conducted for the first time. The performance of fatty acid photodecarboxylase from Chlorella variabilis NC64A ( Cv FAP) was optimized in a biphasic system with petroleum ether as the oil phase; conversion of palmitic acid reached 42.2 % in 1 h, which was 26.4 times that in the single-phase catalysis. This biphasic system was further employed to convert the lipase hydrolysate of waste oil from food waste into hydrocarbon, where the production rate of C17 hydrocarbon was 1.7 mM/h. Meanwhile, the non-oil components from food waste were used in AD to generate C1 hydrocarbon methane. Adding magnetite increased the specific methane yield up to 154.0 % compared to the control group on day 22. The average hydrocarbon generation rate and energy production rate in photoenzymatic decarboxylation were 24.3 and 269 times those in AD, respectively.
研究领域:
环境生物学
·
生物化学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2022
·
IF 5.6
Wenjun He,Gang Chen,Chao Li,Xiaohong Chen,Yaowei Chen,Mengyuan Xiong,Xinsheng Niu,Ming Zhu,Xiaoyan Li
The miniaturization and integration of next-generation electronic devices are accompanied by a substantial increase in electromagnetic interference (EMI) and heat generation, which requires light and thin EMI shielding materials. Herein, we attempt to tackle this challenge by designing a heterogeneous membrane using carbon nanotubes (CNTs) and magnetite (Fe 3 O 4 ) nanorods. The polymer-coated Fe 3 O 4 uniformly adsorbs on the surface of the polyaniline (PANi) coated CNTs, forming a self-supporting composite membrane with vertical CNTs under a magnetic field. Due to the entanglement of the CNTs, the vertical alignment is more effective in the top region of the membrane than in the bottom, resulting in an asymmetric structure that is beneficial to EMI absorption. When electromagnetic waves are incident from the top surface, high-absorption electromagnetic shielding is obtained due to multiple attenuations and absorption-reflection losses. The vertical orientation and heterogeneous CNTs network structure of the membrane also enable stable heat dissipation.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Shijie Wang,Dongdong Jin,Ye Bian,Rutao Wang,Li Zhang
Conversion-type magnetite shrewdly shows abundance, nontoxicity, and high lithium storage capacity. However, either pristine magnetite or nanocomposites with two-dimensional materials cannot prevent restacking, pulverization, and poor structural homogeneity simultaneously because of a lack of universal interfacial interactions. Here, an electrostatic self-assembly strategy is uncovered between hollow Fe3O4/C microspheres (with H+-induced quasi-intrinsic positive charge) and few-layer MXenes (with intrinsic negative charge from terminating functionalities). This strategy realizes the uniform and interconnected architecture of Fe3O4/C@MXene that favors fast Li+ diffusion, easy electron/charge transfer, and suppressed pulverization. Specifically, after the long-term cycling, an undegraded specific capacity of 907 mA h g–1 remains at 0.5 A g–1. Further adoption of such superior anode in 4.0 V lithium-ion capacitors results in a high energy density of 130 W h kg–1, a maximum power density of 25,000 W kg–1, and excellent cycling stability. This work thus sheds light on a generic self-assembly process where intrinsic electrostatic interaction plays an essential role.
研究领域:
材料科学
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能源存储
·
纳米技术
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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）