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

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

Water ◽

10.3390/w12010131 ◽

2019 ◽

Vol 12 (1) ◽

pp. 131 ◽

Cited By ~ 3

Author(s):

Lie Yang ◽

Hong Li ◽

Jianming Xue ◽

Liuyang He ◽

Yongfei Ma ◽

...

Keyword(s):

Aqueous Solutions ◽

Photoelectron Spectroscopy ◽

Speciation Analysis ◽

Zero Valent Iron ◽

Quadratic Model ◽

X Ray ◽

Condition Optimization ◽

Degradation Rates ◽

Nanoscale Zero Valent Iron ◽

Initial Ph

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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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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Preparation of Pd/GO/Cu Electrode and Its Electrochemical Degradation for 2,4-Dichlorophenol

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17416 ◽

2020 ◽

Vol 20 (6) ◽

pp. 3604-3609

Author(s):

Jian Zhang ◽

Yuting Jiang ◽

Bing Wang ◽

Lanhe Zhang ◽

Zheng Li ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Water Environment ◽

Constant Current ◽

Surface Element ◽

Impregnation Method ◽

Electrochemical Degradation ◽

X Ray Diffraction ◽

X Ray ◽

Preparation Conditions ◽

The Stability

Chlorinated aromatic compounds (CACs) are a class of persistent organic pollutants, which have serious damage to water environment due to their own stable structure. But a good many of CACs were abandoned because of their tremendous yields and wide applications, so it is urgent to find the effective degradation methods for CACs. The electrochemical method is supposed to be a simple, environmentally friendly and effective pathway to degrade CACs. In this paper, a Pd/GO/Cu composite electrode was prepared by a combination of impregnation method and constant current electrodeposition method, which showed good electrochemical degradation efficiency for the 2,4-dichlorophenol. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface structure, functional group composition, crystal structure and surface element valence of the electrode. Moreover, the stability of the electrode was investigated, and the preparation conditions of the electrode were optimized.

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Selective Hydrogenation of Benzene to Cyclohexene over Ru-Zn Catalysts: Investigations on the Effect of Zn Content and ZrO2 as the Support and Dispersant

Catalysts ◽

10.3390/catal8110513 ◽

2018 ◽

Vol 8 (11) ◽

pp. 513 ◽

Cited By ~ 2

Author(s):

Haijie Sun ◽

Zhihao Chen ◽

Lingxia Chen ◽

Huiji Li ◽

Zhikun Peng ◽

...

Keyword(s):

Catalytic Activity ◽

Selective Hydrogenation ◽

Photoelectron Spectroscopy ◽

Supported Catalyst ◽

Precipitation Method ◽

Molar Ratio ◽

Impregnation Method ◽

X Ray ◽

Zn Content ◽

Co Precipitation

m-ZrO2 (monoclinic phase) supported Ru-Zn catalysts and unsupported Ru-Zn catalysts were synthesized via the impregnation method and co-precipitation method, respectively. The catalytic activity and selectivity were evaluated for selective hydrogenation of benzene towards cyclohexene formation. Catalyst samples before and after catalytic experiments were thoroughly characterized via X-ray diffraction (XRD), X-ray Fluorescence (XRF), transmission electron microscopy (TEM), N2-sorption, X-ray photoelectron spectroscopy (XPS), H2-temperature programmed reduction (H2-TPR), and a contact angle meter. It was found that Zn mainly existed as ZnO, and its content was increased in Ru-Zn/m-ZrO2 by enhancing the Zn content during the preparation procedure. This results in the amount of formed (Zn(OH)2)3(ZnSO4)(H2O)3 increasing and the catalyst becoming more hydrophilic. Therefore, Ru-Zn/m-ZrO2 with adsorbed benzene would easily move from the oil phase into the aqueous phase, in which the synthesis of cyclohexene took place. The generated cyclohexene then went back into the oil phase, and the further hydrogenation of cyclohexene would be retarded because of the high hydrophilicity of Ru-Zn/m-ZrO2. Hence, the selectivity towards cyclohexene formation over Ru-Zn/m-ZrO2 improved by increasing the Zn content. When the theoretical molar ratio of Zn to Ru was 0.60, the highest cyclohexene yield of 60.9% was obtained over Ru-Zn (0.60)/m-ZrO2. On the other hand, when m-ZrO2 was utilized as the dispersant (i.e., employed as an additive during the reaction), the catalytic activity and selectivity towards cyclohexene synthesis over the unsupported Ru-Zn catalyst was lower than that achieved over the Ru-Zn catalyst with m-ZrO2 as the support. This is mainly because the supported catalyst sample demonstrated superior dispersion of Ru, higher content of (Zn(OH)2)3(ZnSO4)(H2O)3, and a stronger electronic effect between Ru and ZrO2. The Ru-Zn(0.60)/m-ZrO2 was reused 17 times without any regeneration, and no loss of catalytic activity and selectivity towards cyclohexene formation was observed.

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Effect of Ce Addition on Adsorption and Oxidation of NO over MnO x /Al2O3

Adsorption Science & Technology ◽

10.1155/2021/3131309 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Chunhui Mou ◽

Hui Li ◽

Ning Dong ◽

Shien Hui ◽

Denghui Wang

Keyword(s):

Catalytic Activity ◽

Catalytic Oxidation ◽

Photoelectron Spectroscopy ◽

Active Sites ◽

Catalyst Surface ◽

Fixed Bed ◽

No Oxidation ◽

Impregnation Method ◽

X Ray ◽

Oxidation Of No

The MnO x /Al2O3 catalysts with different Ce content doping were prepared by an ultrasonic impregnation method, and the catalytic activity for NO oxidation removal was tested in a fixed-bed quartz tube furnace. Simultaneously, the catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), full-automatic physical-chemical adsorption instrument, and field emission scanning electron microscope (FESEM) to analyze the effect of Ce addition on the adsorption capacity and catalytic activity. Experimental results validated that the activity of the MnO x /Al2O3 catalyst was greatly promoted with Ce addition. According to the characterization results, it could be concluded that Ce doping led to significant changes in the crystalline phase on the catalyst surface, which increased the relative content of surface lattice oxygen and promoted the catalytic oxidation of NO. By observing the physical properties of the surface and analyzing the surface elements of the catalyst, it could be inferred that a manganese-cerium solid solution was formed on the surface of Mn0.4Ce0.05/Al. Moreover, Ce addition increased the catalyst pore size, which enhanced the adsorption and contact of NO and O2 with the active sites on the catalyst surface, and reduced the resistance of the reactants during internal diffusion. All these variations assigned to Mn0.4Ce0.05/Al were favorable for the catalytic oxidation of NO.

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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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Comparison between Different Keratin-composed Biosorbents for the Removal of Heavy Metal Ions from Aqueous Solutions

Adsorption Science & Technology ◽

10.1260/02636170260295579 ◽

2002 ◽

Vol 20 (4) ◽

pp. 393-416 ◽

Cited By ~ 18

Author(s):

Fawzi Banat ◽

Sameer Al-Asheh ◽

Dheaya‘ Al-Rousan

Keyword(s):

Aqueous Solutions ◽

Human Hair ◽

Metal Ion ◽

Ph Value ◽

Freundlich Isotherm ◽

Operating Conditions ◽

Ion Uptake ◽

Chicken Feathers ◽

Initial Ph ◽

Metal Ion Uptake

This study examined and compared the ability of chicken feathers, human hair and animal horns, as keratin-composed biosorbents, for the removal of Zn2+ and Cu2+ ions from single metal ion aqueous solutions under different operating conditions. The three biosorbents investigated in this study were all capable of adsorbing Zn2+ and Cu2+ ions from aqueous solutions. The biosorbent showing the highest uptake of Zn2+ and Cu2+ ions was animal horns. Chicken feathers showed a higher Cu2+ ion uptake and a lower Zn2+ ion compared to human hair. Increasing the initial concentration of Zn2+ or Cu2+ ions, or increasing the initial pH value, increased the metal ion uptake. Such uptake decreased when the temperature was raised from 25°C to 50°C for all adsorbent/metal ion combinations except for Zn2+ ion/human hair where the uptake increased with temperature. It was demonstrated that the addition of NaCl salt to the metal ion solution depressed the metal ion uptake. The Freundlich isotherm model was found to be applicable to the adsorption data for Cu2+ and Zn2+ ions.

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Removal mechanisms of Cd(II) and Pb(II) from aqueous solutions using straw biochar: batch study, Raman and X-ray photoelectron spectroscopy techniques

10.5004/dwt.2021.27011 ◽

2021 ◽

Vol 220 ◽

pp. 199-210

Author(s):

Qingzhou Zhao ◽

Yanfen Wang ◽

Zhihong Xu ◽

Zhisheng Yu

Keyword(s):

Aqueous Solutions ◽

Photoelectron Spectroscopy ◽

X Ray ◽

Removal Mechanisms ◽

Batch Study

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Influence of Sulfur-Containing Sodium Salt Poisoned V2O5–WO3/TiO2 Catalysts on SO2–SO3 Conversion and NO Removal

Catalysts ◽

10.3390/catal8110541 ◽

2018 ◽

Vol 8 (11) ◽

pp. 541 ◽

Cited By ~ 3

Author(s):

Haiping Xiao ◽

Chaozong Dou ◽

Hao Shi ◽

Jinlin Ge ◽

Li Cai

Keyword(s):

Photoelectron Spectroscopy ◽

No Reduction ◽

Catalytic Performance ◽

Acid Sites ◽

Impregnation Method ◽

So2 Oxidation ◽

Sodium Salts ◽

X Ray ◽

Temperature Programmed ◽

Physical Features

A series of poisoned catalysts with various forms and contents of sodium salts (Na2SO4 and Na2S2O7) were prepared using the wet impregnation method. The influence of sodium salts poisoned catalysts on SO2 oxidation and NO reduction was investigated. The chemical and physical features of the catalysts were characterized via NH3-temperature programmed desorption (NH3-TPD), H2-temperature programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FT-IR). The results showed that sodium salts poisoned catalysts led to a decrease in the denitration efficiency. The 3.6% Na2SO4 poisoned catalyst was the most severely deactivated with denitration efficiency of only 50.97% at 350 °C. The introduction of SO42− and S2O72− created new Brønsted acid sites, which facilitated the adsorption of NH3 and NO reduction. The sodium salts poisoned catalysts significantly increased the conversion of SO2–SO3. 3.6%Na2S2O7 poisoned catalyst had the strongest effect on SO2 oxidation and the catalyst achieved a maximum SO2–SO3-conversion of 1.44% at 410 °C. Characterization results showed sodium salts poisoned catalysts consumed the active ingredient and lowered the V4+/V5+ ratio, which suppressed catalytic performance. However, they increased the content of chemically adsorbed oxygen and the strength of V5+=O bonds, which promoted SO2 oxidation.

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