Processes
·
2023
·Vol. 11
·期 3
·903
·
IF 3.5
Yajie Wang,Xin Dong,Chengfeng Liu,Peng Cheng,Gilles Mailhot
The decolorization of azo dye Orange II using a UVA-Fe3+-PMS-oxalate system was studied. A series of experiments was performed to investigate the effects of several variables, including the pH, PMS dosage, Fe3+concentration, oxalate concentration, and coexisting anions. The results revealed that a lower pH facilitated the decolorization, and relatively high decolorization efficiency (97.5%) could be achieved within 5 min at pH 3.0. The electron paramagnetic resonance (ESR) and radical quenching experiments revealed that SO4•−played a crucial role in the decolorization of Orange II (85.8%),•OH was of secondary importance (9%), and1O2made a small contribution to the decolorization (5.2%). Furthermore, the formation of•OH in the experimental system strongly depended on HO2•/O2•−. These reactive oxidants were able to directly attack the azo bond of the luminescent group in Orange II and initiate the decolorization process. The efficient UVA-Fe3+-PMS-oxalate system showed great application potential in the treatment of wastewater contaminated by azo dyes.Keywords:PMS activation;Orange II;decolorization;UVA irradiation;Fe3+-oxalate complexes
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Huiwang Dai,Shuying Xu,Jianxin Chen,Xiaozeng Miao,Jianxi Zhu
Oxalate enhanced mechanism of Fe 3 O 4 @γ-Fe 2 O 3 was developed to provide novel insight into catalytic process regulation of iron oxide catalysts in heterogeneous UV-Fenton system. And the iron oxide composite of Fe 3 O 4 @γ-Fe 2 O 3 was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FTIR) spectroscopy and nitrogen adsorption-desorption isotherms. The results showed that large amount of iron could be leached from catalyst in the presence of oxalate, which promoted the homogeneous UV-Fenton reactions in solution. Orange II degradation could be significantly enhanced with the increase of the ratio of homogeneous UV-Fenton process to heterogeneous UV-Fenton process. The optimum concentration of oxalate determined by experiment was 0.5 mM in oxalate enhanced heterogeneous UV-Fenton system. On this condition, the pseudo-first-order rate constant value of Orange II degradation was 0.314 min −1 , which was 2.3 times as high as that in heterogeneous UV-Fenton system. The removal rates of color and TOC were 100% and 86.6% after 20 min and 120 min treatment, respectively. In addition, the iron ions in solution could be almost completely adsorbed back to the catalyst surface in later degradation stages of Orange II. During the recycle experiments, the results showed that the increase of pH in solution and the sorption of intermediates on the catalyst surface would hinder oxalate enhanced process and lead to a decrease of degradation rate of Orange II in oxalate enhanced heterogeneous UV-Fenton system.
研究领域:
环境科学
·
催化化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 9
·4272-4282
·
IF 3.925
Yu Lei,Huiqi Wu,Jianfeng Ma,Hao Cheng,Sridhar Komarneni
Layered α-Fe2O3/CuS nanoflowers with abundant active sites were synthesized by a hydrothermal method. The heterogeneous composite catalyst of α-Fe2O3/CuS nanoflowers exhibited a remarkable degradation capacity of 97.8% within 25 min for the Orange II (OII) dye under visible light, which was attributed to the synergistic effect of Na2S2O8 to generate ˙SO4− and ˙OH radicals. The initial pH tests revealed that this system showed better adaptability for its application in a wider pH range (pH = 3–9). In addition, the degradation of different azo dyes such as methylene blue (MB), Orange G (OG) and malachite green (MG) was also studied under the same conditions. The catalyst was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) to analyze its size, morphology, valence states of elements and chemical components. α-Fe2O3/CuS was further characterized using a vibrating sample magnetometer (VSM) and diffuse reflectance spectroscopy (DRS) to demonstrate its magnetic properties and light absorption capacity. Moreover, α-Fe2O3/CuS showed good recovery and reuse performance as a catalyst after four repeated cycles. A possible mechanism of degradation was proposed by quenching and ESR experiments, which revealed that the highly active species of ˙SO4−, ˙OH and ˙O2− enhanced the photocatalytic performance of the photocatalytic system.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 19
·19122-19133
·
IF 2.8
Ren Bin,Wang Tiecheng,Qu Guangzhou,Deng Fang,Liang Dongli,Yang Wenli,Liu Meishan
As a highly active photocatalyst, g-C 3 N 4 /TiO 2 heterojunction nanocomposites were in situ synthesized by simple ultrasonic mixing and calcination by using TiO 2 and melamine as precursors. The morphology and structure of the prepared photocatalysts were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, UV-Vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activities of g-C 3 N 4 /TiO 2 nanocomposites to degrade Orange II (AO7) under visible light irradiation were evaluated. Results showed that the photocatalytic rate of the prepared g-C 3 N 4 /TiO 2 photocatalyst to degrade AO7 was about three times than that of pristine TiO 2 and g-C 3 N 4 . The g-C 3 N 4 /TiO 2 composite with a ratio of 1:4 had the highest degradation efficiency for AO7 solution. Its degradation efficiency under acidic conditions was significantly higher than that under alkaline conditions. The enhancement of photocatalytic activity can be attributed to the formation of heterojunctions between g-C 3 N 4 and TiO 2 , which leads to rapid charge transfer and the efficient separation of photogenerated electron-hole pairs. The recycling experiment indicated that the photocatalyst of g-C 3 N 4 /TiO 2 nanocomposites still maintained good photochemical stability and recyclability after five cycles; this finding was important for its practical applications. A series of free radical trapping experiments showed that •O 2 − played a crucial role in the degradation of AO7.
ᅟ
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Yanping Zhu,Minwang Laipan,Runliang Zhu,Tianyuan Xu,Jing Liu,Jianxi Zhu,Yunfei Xi,Gangqiang Zhu,Hongping He
A novel and efficient photocatalyst was synthesized by surface hybridizing Zn/Ti-LDH (LDH) with C60 molecules. The structural characteristics of the resulting products (C60/LDH) were studied using a variety of characterization methods, and the photocatalytic activities of C60/LDH were tested using Orange II (OII) as a model contaminant under simulated solar irradiation. The FT-IR spectra showed that the characteristic mode of C60 at 1182 cm −1 split into two peaks at approximately 1240 and 1156 cm −1 ; in addition, the Raman spectra showed the band at 1422 cm −1 for C60 was upshifted to 1431 cm −1 with the increased doping amount of C60. In addition, the XPS spectra revealed that the peaks of O1s, Zn 2p, and Ti 2p were downshifted slightly. These results demonstrated that chemical interaction existed between C60 and LDH on C60/LDH. The UV–vis diffuse reflectance spectra confirmed that the absorbance of C60/LDH in visible-light region enhanced markedly, as compared with that of pristine LDH. The photoluminescence (PL) spectroscopic measurement revealed that the C60/LDH composites exhibited much weaker PL intensity than that of LDH sample, and the transient photocurrent ( I – V ) analysis showed that C60/LDH had higher photocurrent density than pristine LDH. The results of PL spectra and I–V analysis suggested that C60 molecule could effectively transfer the photoelectrons from the conduction band of LDH, leading to a lower recombination rate of the photo-induced electrons and holes. The photocatalytic experiments showed that C60/LDH had much higher photocatalytic activity in the decolorization of OII than that of pristine LDH, and 2%C60/LDH composite exhibited the highest photocatalytic activity. Furthermore, the stability test indicated that the decolorization efficiency of OII by 2%C60/LDH was still quite efficient after being used for 5 cycles.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
Catalysts
·
2024
·Vol. 14
·期 11
·758
·
IF 3.8
Yujuan Li,He Guo,Hu Li,Tiecheng Wang
Dye wastewater is characterized by high salinity, intense coloration, difficulty in degradation, and complex organic compositions, posing significant environmental risks. Manganese oxide (MnxOy)-based materials have been widely used for the removal of recalcitrant organic pollutants in water environments. In this study, various MnxOypolymorphs were prepared, and their catalytic activities for persulfate (PS) activation were evaluated using Orange II (AO7) as a model molecule. After 50 min treatment, the degradation efficiency of AO7 ranked asα-MnO2/PS >γ-MnO2/PS >β-MnO2/PS > Mn2O3/PS, withα-MnO2/PS achieving the highest efficiency of 98.6%. XPS, XRD, and electrochemical analyses indicated thatα-MnO2exhibited an exceptional crystal structure and performance. Theα-MnO2/PS system exhibited a strong pH adaptability across a wide pH range of 3.0–9.0. The presence of coexisting anions at 0.1 mM, including Cl−, NO3−, CO32−, and SO42−, slightly reduced the degradation rate of AO7. The reactive oxygen species, mainly SO4•−and1O2, predominantly destroyed the naphthalene ring structure of AO7. Furthermore,α-MnO2exhibited an excellent stability, allowing for multiple reuse cycles without interference from common anions in water, highlighting its strong potential for practical applications. These results provided insights into the environmental fates of AO7 in theα-MnO2/PS system.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Xiaozeng Miao,Huiwang Dai,Jianxin Chen,Jianxi Zhu
An enhanced method of hydroxyl radical generation was studied to lead a better understanding of the catalytic mechanism of α-FeOOH in UV-Fenton system. The catalyst was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption–desorption isotherms and scanning electron microscope. The Orange II degradation and hydroxyl radical concentration under different conditions were studied in detail. The results showed that the hydroxyl radical was mainly oxidizing species for Orange II degradation. And the hydroxyl radical generation included both homogeneous and heterogeneous UV-Fenton processes. In heterogeneous UV-Fenton system, the additional oxalate could increase the ratio of homogeneous UV-Fenton process for hydroxyl radical generation. In oxalate enhanced system, the peak value of hydroxyl radical concentration would increase to 11.314 μmol/L which was nearly twice as it in heterogeneous UV-Fenton system (5.978 μmol/L). The k values of Orange II discoloration and mineralization increased to 0.386 min −1 and 0.044 min −1 , which were 1.169 and 0.692 times as that in heterogeneous UV-Fenton system (0.178 min −1 and 0.026 min −1 ). After treatment, the total iron ions concentration decreased to 2.357 μmol/L in oxalate enhanced system. The results indicated that additional oxalate was a promising enhanced method for hydroxyl radical generation in heterogeneous UV-Fenton system with α-FeOOH as catalyst.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Huixin Xiong,Bailin Zhang,Can Cui,Yiqun Xu
The synthesized polyaniline/FeOOH composite characterized by SEM, HRTEM, XRD , FT-IR and BET, was used as adsorbent for Acid Orange II (AOII). The kinetics, isotherm and thermodynamics of AOII adsorption by polyaniline/FeOOH were studied by batch experiments. And effects of pH and coexisting ions on AOII removals were also investigated. Adsorption kinetics and isotherm well fitted pseudo second-order kinetic model and Langmuir isotherm model, respectively. The maximum adsorption capacity of polyaniline/FeOOH for AOII could reach 155.8 mg g −1 . It showed that polyaniline/FeOOH composite could rapidly and efficiently remove AOII from aqueous solutions. In addition, thermodynamic result indicated that the adsorption was a spontaneous endothermic process. Removal ratio of AOII (100 mg/L) increased as pH decreased and could reach 98.6% at pH3. And anions coexisting in the solutions could inhibit the adsorption effect, while the cations have negligible influence. Also, PANI/FeOOH had better applicability to the different types of anionic dyes. The regeneration of polyaniline/FeOOH loading 98.6% of AOII evaluated for three cycles and there was about 70% of AOII loaded on final adsorbent.
研究领域:
环境科学
·
材料科学
·
物理化学
·
水处理技术
·
吸附科学
✓ 已验证
DOI
高影响因子
Separations
·
2025
·Vol. 12
·期 4
·101
·
IF 2.7
Jiren Yuan,Dongao Xie,Dan Li,Feigao Xu
In recent years, the rapid development of industry has led to the discharge of large quantities of pollutants, including harmful dyes, into water sources, thereby posing potential threats to human health and the environment. FeOCl and biochar have their own shortcomings as a mediator in the heterogeneous Fenton process. To make both materials useful, FeOCl supported on bamboo biochar (FeOCl/BC) was prepared by calcination using FeCl3·6H2O and bamboo powder as raw materials, and the composite’s catalytic activities were explored with acid orange II (AO-II) as the target pollutant. The degradation efficiency of FeOCl/BC composites on AO-II was determined by testing the mass ratio of FeOCl and BC, initial pH, temperature, H2O2concentration, catalyst addition, addition of coexisting inorganic anions, and natural organic matter. The addition of biochar to FeOCl increased the activation of H2O2to generate •OH for the removal of AO-II and accelerated the cycle of Fe3+/Fe2+. The removal rate of AO-II by the Fe1C0.2composite was 97.1% when the mass ratio of FeOCl and BC was 1:0.2 (Fe1C0.2), which was higher than that of the pure components (FeOCl or BC) at pH = 6.1. Moreover, after five reuses, the Fe1C0.2composite still showed high degradation activity for AO-II, with 83.3% degradation and low activity loss. The capture experiments on the active material showed that the removal of AO-II by the Fe1C0.2composite was mainly dominated by •OH; however, •O2−andh+played minor roles. The synthesized Fe1C0.2composite could be applied for organic contaminants such as AO-II with high removal efficiency.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Environmental Chemistry Letters
·
2019
·Vol. 17
·期 3
·1435-1439
·
IF 4.617
Chen Yiqun,Tong Yang,Liu Zizheng,Huang Li-Zhi,Yuan Jianping,Xue Yingwen,Fang Zheng
UV-activated persulfate (PS) systems have been widely employed to remove organic contaminants. However, the heavy use of persulfate may lead to secondary pollution. Here we proposed a novel UV/PS/sulfite oxidation process, in which sulfite would not only promote but also partially replace persulfate to produce sulfate radicals. We tested this system using Orange II as a model compound. Results show that the use of sulfite improves the degradation of Orange II. For instance, increasing the molar ratio of sulfite to persulfate in the range of 0.05–0.5 enhanced the removal efficiency by 21.7%. Compared to the UV/PS system, the presence of sulfite can achieve a 33.4% higher performance. We also found that the absence of dissolved oxygen remarkably inhibited the oxidation of Orange II. SO
·− 4
, SO
·− 5
and HO · were identified in the UV/PS/sulfite system, and SO
·− 4
and HO · should be primarily responsible for Orange II removal.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
Jing Deng,ShanFang Feng,Xiaoyan Ma,Chaoqun Tan,Hongyu Wang,Shiqing Zhou,Tuqiao Zhang,Jun Li
Highly ordered mesoporous MnFe 2 O 4 was fabricated via the nanocasting strategy and innovatively used to activate peroxymonosulfate for the degradation of Orange II in water. The effects of several key parameters including catalyst dosage, peroxymonosulfate concentration, temperature and initial pH on the degradation performance were investigated. Results showed that the catalytic activity of ordered mesoporous MnFe 2 O 4 was far superior than that of spinel MnFe 2 O 4 , which can be attributed to its unique structural characteristics. Data fitting showed that the Orange II degradation could be described by the pseudo-first-order kinetics under all conditions tested in this study. Ordered mesoporous MnFe 2 O 4 presented stable and excellent catalytic activity in wide pH range of 5–9. Both the increase of catalyst dosage and temperature favored the enhancement in catalytic efficiency. However, the Orange II degradation tended to have a decline trend after an initial ascent as the peroxymonosulfate concentration increased. Moreover, ordered mesoporous MnFe 2 O 4 was reusable over five consecutive cycles and negligible leaching of metal ions was observed during catalytic reaction. The balance among Mn 2+ /Mn 3+ , Fe 2+ /Fe 3+ and peroxymonosulfate decomposed in solution was considered as the proposed activation mechanism, and the generation of sulfate radicals played the dominant role in the Orange II degradation.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Lingli Ji,Qixing Xiao,Lijun Zhu,Sridhar Komarneni,Jianfeng Ma
Carbon dots (CDs)-modified Cr 2 O 3 (CDs@Cr 2 O 3 ) composites were synthesized by solvothermal process followed by calcination to improve their catalytic performance. The physical and chemical properties of the composites were determined by XRD , SEM , TEM, BET and XPS . With the aid of sodium persulfate, the activity of CDs@Cr 2 O 3 to oxidize Orange II by non-radicals was studied under various conditions. The experimental results determined the optimal dosage of PDS to be 0.1 g and the degradation results showed that after 45 min, the degradation rate of Orange II reached to 98.4% with the CDs@Cr 2 O 3 /PDS/Vis system. The adsorption capacity of CDs@Cr 2 O 3 for Orange II was closely related to pH, and this phenomenon is further explained by the isoelectric point. A series of experiments proved that non-free radicals played a crucial role in the oxidation process , in which singlet oxygen ( 1 O 2 ), superoxide radical (O 2 •− ) and photo-generated holes (h + ) were determined as the important reactive oxygen species (ROS). In addition, the present study found that increasing dissolved oxygen could promote the reaction and the catalyst maintained good degradation performance after five cycles suggesting its stability.
研究领域:
环境科学
·
催化材料
✓ 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）