Hydrothermal Enhanced Nanoscale Zero-Valent Iron Activated Peroxydisulfate Oxidation of Chloramphenicol in Aqueous Solutions: Fe-Speciation Analysis and Modeling Optimization

The efficiencies of the nanoscale zero-valent iron (nZVI) and hydrothermal and nZVI-heat activation of peroxydisulfate (PS) were studied for the decomposition of chloramphenicol (CAP) in aqueous solutions. The nZVI heat combined with activation of PS provided a significant synergistic effect. A central composite design (CCD) with response surface methodology (RSM) was employed to explore the influences of single parameter and interactions of selected variables (initial pH, PS concentration, nZVI and temperature) on degradation rates with the purpose of condition optimization. A quadratic model was established based on the experimental results with excellent correlation coefficients of 0.9908 and 0.9823 for R2 and R2adj. The optimized experimental condition for 97.12% CAP removal was predicted with the quadratic model as 15 mg/L, 0.5 mmol/L, 7.08 and 70 °C for nZVI dosage, PS, initial pH, and temperature, respectively. This study demonstrated the effectiveness of RSM for the modeling and prediction of CAP removal processes. In the optimal condition, Fe2O3 and Fe3O4 were the predominant solid products after reactions based on X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis, which could also act as the activators along with the reaction. Overall, it could be concluded that hydrothermal enhanced nZVI activation of PS was a promising and efficient choice for CAP degradation.

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Property of Cu2O-CuO/ZSM-5 nanocomposite and degradation process of azo dye AO7 without sacrificial agent (H2O2)

Water Science & Technology ◽

10.2166/wst.2016.138 ◽

2016 ◽

Vol 73 (11) ◽

pp. 2747-2753 ◽

Cited By ~ 2

Author(s):

Wusong Kong ◽

Hongxia Qu ◽

Peng Chen ◽

Weihua Ma ◽

Huifang Xie

Keyword(s):

Catalytic Activity ◽

Aqueous Solutions ◽

Photoelectron Spectroscopy ◽

Oxygen Demand ◽

Operating Conditions ◽

Surface Element ◽

Impregnation Method ◽

X Ray ◽

Initial Ph ◽

Sacrificial Agent

In this study, Cu2O-CuO/ZSM-5 nanocomposite was synthesized by the impregnation method, and its catalytic performance for the destruction of AO7 in aqueous solutions was investigated. The morphology, structure and surface element valence state of Cu2O-CuO/ZSM-5 were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The operating conditions on the degradation of AO7 by Cu2O-CuO/ZSM-5, such as initial pH values, concentration of AO7 and catalyst dosage were investigated and optimized. The results showed that the sample had good catalytic activity for destruction of AO7 in the absence of a sacrificial agent (e.g. H2O2): it could degrade 91% AO7 in 140 min at 25 °C and was not restricted by the initial pH of the AO7 aqueous solutions. Cu2O-CuO/ZSM-5 exhibited stable catalytic activity with little loss after three successive runs. The total organic carbon and chemical oxygen demand removal efficiencies increased rapidly to 69.36% and 67.3% after 120 min of treatment by Cu2O-CuO/ZSM-5, respectively.

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A Facile Strategy to Fabricate Nanoscale Zero-Valent Iron Decorated Graphene Oxide Composite for Dechloridation of Trichloroacetic Acid in Water

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2018.16374 ◽

2018 ◽

Vol 18 (12) ◽

pp. 8252-8257 ◽

Cited By ~ 1

Author(s):

Huixuan Zhang ◽

Xinyi Zhang ◽

Ruonan Guo ◽

Qingfeng Cheng ◽

Xiuwen Cheng

Keyword(s):

Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Sewage Treatment ◽

Reduction Process ◽

Zero Valent Iron ◽

Chlorinated Organic Compounds ◽

X Ray ◽

Transmission Electron ◽

Nanoscale Zero Valent Iron ◽

Adsorption Desorption

In this study, nanoscale zero-valent iron decorated graphene oxide (NZVI/GO) composite was fabricated through a reduction process in the presence of sodium borohydride (NaBH4) solution. Subsequently, physicochemical properties of the NZVI/GO composites were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy (FT-IR) and Raman spectra. Results indicated that Fe species existed in the form of Fe0, which uniformly dispersed on the surface of GO. Furthermore, the performance of NZVI/GO was evaluated by the degradation of tichloroacetic acid (TCAA). TCAA can be rapidly degraded by NZVI/GO. This paper provides a promising strategy to synthesize versatile catalyst which would be potentially applied in sewage treatment to degrade chlorinated organic compounds.

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Removal efficiency of hexavalent chromium from wastewater using starch-stabilized nanoscale zero-valent iron

Water Science & Technology ◽

10.2166/wst.2019.358 ◽

2019 ◽

Vol 80 (6) ◽

pp. 1076-1084 ◽

Cited By ~ 2

Author(s):

Hualin Chen ◽

Huajun Xie ◽

Jiangmin Zhou ◽

Yueliang Tao ◽

Yongpu Zhang ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

High Reactivity ◽

Zero Valent Iron ◽

X Ray Diffraction ◽

X Ray ◽

Phase Reduction ◽

Nanoscale Zero Valent Iron ◽

Removal Efficiencies ◽

Ph Range ◽

Uniform Particle Size

Abstract In this study, starch-stabilized nanoscale zero-valent iron (S-nZVI) was produced using the liquid-phase reduction method. It was used to remove chromium from wastewater, and compared to a commercial nanoscale zero-valent iron (C-nZVI). Both nZVIs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The characterization results showed that S-nZVI had smaller particles and a more uniform particle size distribution than C-nZVI. Both nZVIs showed a core-shell structure with the Fe0 core prominently surrounded by less iron oxides of Fe2+ and Fe3+. The optimal application methods to remove Cr(VI) from wastewater were also explored. The results showed that both the removal efficiencies of total Cr and Cr(VI) increased with increases in the addition of nZVIs, while the removal efficiencies of total Cr and Cr(VI) by S-nZVI were clearly higher than that of C-nZVI, especially in a low pH range (pH = 1.0–6.0). This research indicated that starch-stabilized nanoscale zero-valent iron is a valuable material to remove heavy metals from wastewater due to its stability and high reactivity.

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Adsorption characteristics of Pb(II) from aqueous solutions onto a natural biosorbent, fallen arborvitae leaves

Water Science & Technology ◽

10.2166/wst.2016.104 ◽

2016 ◽

Vol 73 (10) ◽

pp. 2422-2429 ◽

Cited By ~ 8

Author(s):

Jie Shi ◽

Zhiwei Zhao ◽

Zhijie Liang ◽

Tianyi Sun

Keyword(s):

Aqueous Solutions ◽

Photoelectron Spectroscopy ◽

Pore Diameter ◽

Surface Complexation ◽

Zero Point ◽

X Ray ◽

High Potentials ◽

Initial Ph ◽

Natural Organic Matters ◽

Adsorbent Dose

In this study, the potential of the oriental arborvitae leaves for the adsorption of Pb(II) from aqueous solutions was evaluated. Brunauer–Emmett–Teller analysis showed that the surface area of arborvitae leaves was 29.52 m2/g with pore diameter ranging from 2 to 50 nm. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy showed C—;C or C—;H, C—;O, and O—;C=O were the main groups on the arborvitae leaves, which were the main sites for surface complexation. Finally, effects of adsorbent dose, initial pH, contact time, and coexisting natural organic matters (humic acid (HA)) on the adsorption of Pb(II) were investigated. The results indicated that the pHZPC (adsorbents with zero point charge at this pH) was 5.3 and the adsorption reached equilibrium in 120 min. Isotherm simulations revealed that the natural arborvitae leaves exhibit effective adsorption for Pb(II) in aqueous solution, giving adsorptive affinity and capacity in an order of ‘no HA’ > 5 mg/L HA > 10 mg/L HA, and according to the Langmuir models, the maximum adsorptions of Pb(II) were 43.67 mg/g, 38.61 mg/g and 35.97 mg/g, respectively. The results demonstrated that the oriental arborvitae leaves showed high potentials for the adsorption of Pb(II) from aqueous solutions.

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Mechanism of Cu2+ Ions Removal from Aqueous Solution with PBTCA Modified Fe0 Nanoparticles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.522-524.454 ◽

2014 ◽

Vol 522-524 ◽

pp. 454-457

Author(s):

Jing Wei Feng ◽

Ying Xia Xu

Keyword(s):

Aqueous Solution ◽

Iron Oxide ◽

Photoelectron Spectroscopy ◽

Aqueous Media ◽

Zero Valent Iron ◽

Borohydride Reduction ◽

Experimental Conditions ◽

Redox Mechanism ◽

X Ray ◽

Nanoscale Zero Valent Iron

Applications of PBTCA modified nanoscale zero valent iron (P-Fe0) prepared by borohydride reduction for removal of Cu2+ions from aqueous solution are investigated under a variety of experimental conditions. According to X-ray photoelectron spectroscopy (XPS) results, Cu2+ions were removed primarily via a redox mechanism that resulted in the formation of Cu0and Cu2O. The contact of P-Fe0with aqueous media caused extensive formation of iron oxide.

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TBO Degradation by Heterogeneous Fenton-like Reaction Using Fe Supported over Activated Carbon

Catalysts ◽

10.3390/catal11121456 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1456

Author(s):

Brahim Samir ◽

Soumia Bakhta ◽

Nabil Bouazizi ◽

Zahra Sadaoui ◽

Ouiza Allalou ◽

...

Keyword(s):

Activated Carbon ◽

Photoelectron Spectroscopy ◽

Waste Product ◽

Heterogeneous Fenton ◽

Sem Images ◽

X Ray ◽

Fe Catalyst ◽

Degradation Rates ◽

Initial Ph ◽

Hazardous Pollutants

This study reports on the synthesis, immobilization, and stabilization of iron (Fe) particles in activated carbon (AC) from date stem material for the heterogeneous Fenton-like removal of hazardous pollutants from water. AC-Fe was synthesized through a simple and sustainable chemical reaction using and resulting in an environmentally friendly material (AC-Fe). X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray analyses (EDX) were used to characterize the synthesized samples. XRD, FTIR and XPS results showed the successful incorporation of iron particles onto AC. SEM images indicated smooth surfaces with clearly visible Fe particles. Compared to pure AC, AC-Fe showed higher degradation rates of toluidine blue O (TBO) dye. The effects of the initial pH and TBO and H2O2 concentrations on TBO degradation were investigated. The AC-Fe catalyst proved highly efficient in the Fenton-like degradation of TBO (50 ppm), with the removal of up to 99% in 3 min. This catalyst was used efficiently for up to four repeated cycles. The improved catalytic activity of AC-Fe was related to Fe particles for the generation of HO•. These results prove that date stems—a waste product from agriculture—are a suitable precursor for preparing an appropriate AC and catalyst and for eliminating dyes from an aqueous solution by a heterogeneous Fenton-like reaction. The above results open an interesting avenue for the development of functional green catalysts based on AC-Fe for pollution removal.

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Simultaneous adsorption and reduction of hexavalent chromium on biochar-supported nanoscale zero-valent iron (nZVI) in aqueous solution

Water Science & Technology ◽

10.2166/wst.2020.392 ◽

2020 ◽

Vol 82 (7) ◽

pp. 1339-1349

Author(s):

Fengfeng Ma ◽

Bakunzibake Philippe ◽

Baowei Zhao ◽

Jingru Diao ◽

Jian Li

Keyword(s):

Electron Microscopy ◽

Aqueous Solution ◽

Photoelectron Spectroscopy ◽

Zero Valent Iron ◽

X Ray Diffraction ◽

Experimental Conditions ◽

X Ray ◽

Transmission Electron ◽

Nanoscale Zero Valent Iron ◽

Pseudo Second Order

Abstract Flax straw biochar (FSBC)-supported nanoscale zero-valent iron (nZVI) composite (nZVI-FSBC) combining the advantages of nZVI and biochar was synthesized and tested for Cr(VI) removal efficiency from aqueous solution. Surface morphology and structure of FSBC and nZVI-FSBC were characterized by scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller techniques, which help to clarify the mechanism of Cr(VI) removal from aqueous solution. The adsorption of Cr(VI) onto FSBC and nZVI-FSBC was best described by the pseudo-second-order and the Sips model. Compared with FSBC, nZVI-FSBC remarkably improved the performance in removing Cr(VI) under identical experimental conditions. Due to the collaborative effect of adsorption and reduction of nZVI-FSBC, the adsorption capacity of nZVI-FSBC for Cr(VI) is up to 186.99 mg/g. The results obtained by XPS, XRD, and FTIR confirmed that adsorption and reduction dominated the processes of Cr(VI) removal by nZVI-FSBC. As a supporter, FSBC not only improved the dispersion of nZVI, but also undertook the adsorption task of Cr(VI) removal. The surface oxygen-containing functional groups of nZVI-FSBC mainly participated in the adsorption part, and the nZVI promoted the Cr(VI) removal through the redox reactions. These observations indicated that the nZVI-FSBC can be considered as potential adsorbents to remove Cr(VI) for environment remediation.

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Removal of molybdenum(VI) from aqueous solutions using nano zero-valent iron supported on biochar enhanced by cetyl-trimethyl ammonium bromide: adsorption kinetic, isotherm and mechanism studies

Water Science & Technology ◽

10.2166/wst.2018.258 ◽

2018 ◽

Vol 2017 (3) ◽

pp. 859-868 ◽

Cited By ~ 6

Author(s):

J. J. Lian ◽

Y. G. Huang ◽

B. Chen ◽

S. S. Wang ◽

P. Wang ◽

...

Keyword(s):

Aqueous Solutions ◽

Photoelectron Spectroscopy ◽

Cetyl Trimethyl Ammonium Bromide ◽

Zero Valent Iron ◽

Ammonium Bromide ◽

Standard Entropy ◽

X Ray ◽

Pseudo Second Order ◽

Cetyl Trimethyl Ammonium ◽

Isotherm Equations

Abstract A new carbonized pomelo peel biosorbent (MCPP) modified with nanoscale zero-valent iron (NZVI) and cetyl-trimethyl ammonium bromide was prepared and employed for the adsorption of molybdate (Mo(VI)) from aqueous solution. We investigated the effects of various conditions on Mo(VI) adsorption and evaluated the results based on adsorption kinetics models and isotherm equations. The kinetic data fitted to the pseudo-second-order model. The Langmuir model best described the adsorption of Mo(VI) on MCPP. The values of changes in Gibbs free energy, standard enthalpy, and standard entropy revealed that the adsorption process was feasible, spontaneous and endothermal. X-ray diffraction, Fourier transform infrared and X-ray photoelectron spectroscopy measurements suggested that Mo(VI) adsorption occurred via both the reduction and surface adsorption. Thus, biochar, prepared from fruit residue, can be applied to remove Mo(VI) from aqueous solutions. More importantly, our results provide a sustainable approach for Mo(VI) removal from wastewater by means of functional modification.

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Efficient Sequestration of Hexavalent Chromium by Graphene-Based Nanoscale Zero-Valent Iron Composite Coupled with Ultrasonic Pretreatment

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18115921 ◽

2021 ◽

Vol 18 (11) ◽

pp. 5921

Author(s):

Haiyan Song ◽

Wei Liu ◽

Fansheng Meng ◽

Qi Yang ◽

Niandong Guo

Keyword(s):

Aqueous Solution ◽

Removal Efficiency ◽

Inhibitory Effect ◽

Ultrasonic Cavitation ◽

Zero Valent Iron ◽

Ultrasonic Pretreatment ◽

Nanoscale Zero Valent Iron ◽

Passivation Layers ◽

Initial Ph ◽

Two Phases

Nanoscale zero-valent iron (nZVI) has attracted considerable attention for its potential to sequestrate and immobilize heavy metals such as Cr(VI) from an aqueous solution. However, nZVI can be easily oxidized and agglomerate, which strongly affects the removal efficiency. In this study, graphene-based nZVI (nZVI/rGO) composites coupled with ultrasonic (US) pretreatment were studied to solve the above problems and conduct the experiments of Cr(VI) removal from an aqueous solution. SEM-EDS, BET, XRD, and XPS were performed to analyze the morphology and structures of the composites. The findings showed that the removal efficiency of Cr(VI) in 30 min was increased from 45.84% on nZVI to 78.01% on nZVI/rGO and the removal process performed coupled with ultrasonic pretreatment could greatly shorten the reaction time to 15 min. Influencing factors such as the initial pH, temperature, initial Cr(VI) concentration, and co-existing anions were studied. The results showed that the initial pH was a principal factor. The presence of HPO42−, NO3−, and Cl− had a strong inhibitory effect on this process, while the presence of SO42− promoted the reactivity of nZVI/rGO. Combined with the above results, the process of Cr(VI) removal in US-nZVI/rGO system consisted of two phases: (1) The initial stage is dominated by solution reaction. Cr(VI) was reduced in the solution by Fe2+ caused by ultrasonic cavitation. (2) In the following processes, adsorption, reduction, and coprecipitation coexisted. The addition of rGO enhanced electron transportability weakened the influence of passivation layers and improved the dispersion of nZVI particles. Ultrasonic cavitation caused pores and corrosion at the passivation layers and fresh Fe0 core was exposed, which improved the reactivity of the composites.

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Fabrication of Carboxymethylcellulose/Metal-Organic Framework Beads for Removal of Pb(II) from Aqueous Solution

Materials ◽

10.3390/ma12060942 ◽

2019 ◽

Vol 12 (6) ◽

pp. 942 ◽

Cited By ~ 10

Author(s):

Huo-Xi Jin ◽

Hong Xu ◽

Nan Wang ◽

Li-Ye Yang ◽

Yang-Guang Wang ◽

...

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Photoelectron Spectroscopy ◽

Langmuir Isotherm ◽

Adsorption Equilibrium ◽

Isotherm Model ◽

Maximum Adsorption Capacity ◽

X Ray ◽

Metal Organic ◽

Langmuir Isotherm Model

The ability to remove toxic heavy metals, such as Pb(II), from the environment is an important objective from both human-health and ecological perspectives. Herein, we describe the fabrication of a novel carboxymethylcellulose-coated metal organic material (MOF-5–CMC) adsorbent that removed lead ions from aqueous solutions. The adsorption material was characterized by Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. We studied the functions of the contact time, pH, the original concentration of the Pb(II) solution, and adsorption temperature on adsorption capacity. MOF-5–CMC beads exhibit good adsorption performance; the maximum adsorption capacity obtained from the Langmuir isotherm-model is 322.58 mg/g, and the adsorption equilibrium was reached in 120 min at a concentration of 300 mg/L. The adsorption kinetics is well described by pseudo-second-order kinetics, and the adsorption equilibrium data are well fitted to the Langmuir isotherm model (R2 = 0.988). Thermodynamics experiments indicate that the adsorption process is both spontaneous and endothermic. In addition, the adsorbent is reusable. We conclude that MOF-5–CMC is a good adsorbent that can be used to remove Pb(II) from aqueous solutions.

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