JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2015
·Vol. 91
·期 4
·985-993
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IF 2.349
Jiang Lu,Xiaodan Wei,Yu Chang,Shuanghong Tian,Ya Xiong
BACKGROUND An ozonation catalyst needs to be recycled easily and to exhibit high activity in view of its practical application in wastewater treatment. In this study, magnetic mesoporous MgFe 2 O 4 was successfully prepared and used as a new ozonation catalyst for degradation of Acid Orange II (AOII). The role of Mg in MgFe 2 O 4 was revealed to explain the high activity by catalytic experiments and XPS analysis. RESULTS The degradation efficiency of AOII in the MgFe 2 O 4 /O 3 process exceeds 90% over a wide pH range of 4.6–9.6, slightly affected by the solution pH. The catalytic activity of MgFe 2 O 4 is much higher than that of MgO, Fe 2 O 3 and also their mixture (MgO+Fe 2 O 3 ) with identical molar ratio of Mg 2+ to Fe 3+ , indicating the first role of Mg, i.e. coupling with Fe to present a synergistically catalytic effect. Furthermore, MgFe 2 O 4 possesses a reaction rate constant at least 2.3 times that of NiFe 2 O 4 , MnFe 2 O 4 , and CuFe 2 O 4 . It illustrates the second role of Mg, i.e. causing the high electron density on lattice oxygen in MgFe 2 O 4 indicated by XPS and thus favoring activation of the electrophilic ozone. CONCLUSIONS This study demonstrated the easy recycling and high activity of MgFe 2 O 4 in catalytic ozonation, and revealed the role of Mg in MgFe 2 O 4 . © 2015 Society of Chemical Industry
研究领域:
环境科学
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催化材料
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DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Zhipan Wen,Yalei Zhang,Gang Cheng,Yingru Wang,Rong Chen
In this study, nanosized ordered magnetic mesoporous Fe-Ce bimetal oxides (Nanosized-MMIC) with highly well-ordered inner-connected mesostructure were successfully synthesized through the KIT-6 template method. This Nanosized-MMIC displayed excellent adsorption capacities for As(V), Cr(VI) and AO7, and the corresponding calculated maximum adsorption capacities of material were 111.17, 125.28 and 156.52 mg/g, respectively. As(V) and Cr(VI) removal by Nanosized-MMIC were slightly dependent on the ionic strength but highly solution pH-dependent, the coexistent silicate and phosphate ions competed remarkably with both As(V) and Cr(VI) for the adsorption active site. Mechanisms indicated As(V) and Cr(VI) formed inner-sphere complexes on Nanosized-MMIC interface via the electrostatic interaction and surface complexation, while the total organic carbon (TOC) change demonstrated that AO7 could be removed completely and no organic intermediates formed through the adsorption process. In addition, Nanosized-MMIC also possessed superior adsorption performance in As(V)/Cr(VI)-AO7 binary systems, and the reusable and regeneration properties indicated that the obtained nanomaterials could maintain at a comparatively high level after several recycling. Finally, fixed-bed experiments suggested the Nanosized-MMIC was expected to have a promising excellent nano-adsorbent with high application potential for co-existed toxic heavy metals and organic dyes removal in practical wastewater treatment .
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
WATER AIR AND SOIL POLLUTION
·
2022
·Vol. 233
·期 9
·1-13
·
IF 2.984
Wu Wei,Duan Huike,Chen Jiabin,Xu Jie,Xu Fen,Huang Tianyin,Xu Xiaoyi
In this study, the azo dye acid orange 7 (AO7) was degraded by synergistic activation of persulfate (PMS) with cyclohexanone/chloride ion (Cl − ). The effects of cyclohexanone dosage, PMS concentration, Cl − concentration, initial pH, temperature, and aqueous natural organic matter (NOM) on the AO7 removal were investigated. Under alkaline conditions, the removal rate of AO7 increased with increasing cyclohexanone and Cl − concentrations. The degradation rate of AO7 was unaffected by the water matrix and NOM in the environment. As shown in radical quenching experiments and electron paramagnetic resonance spectroscopy analysis, the main reactive species generated in the reaction system were hypochlorous acid (HCIO) and singlet oxygen ( l O 2 ), which destroyed the azo bond and naphthalene ring structure in AO7. Judging from its ability to degrade AO7, the cyclohexanone/Cl − /PMS system is suitable for treating high-salt wastewater containing organic pollutants.
研究领域:
环境科学
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化学
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DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2024
·Vol. 50
·期 6
·2743-2761
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IF 2.8
Lin Yingzi,Chen Jing,Chen Junjie,Chen Lei,Yang Hong,Sun ShengBo,Sun Ningning,Weng Qixuan,Tian Shiqi
To address the disadvantage of poor degradation effect of Fe 2+ /peroxydisulfate (PDS) system, a co-catalyst was introduced in this study to construct a molybdenum (Mo)/Fe 2+ /PDS system for the degradation of Acid Orange 7 (AO7), and the degradation rate could reach 95.67%. The effects of different parameters (initial pH, Fe 2+ concentration, etc.) on the degradation effect of AO7 in this system were investigated, and the optimal degradation conditions were obtained by combining cost analysis. Cycling experiments showed that Mo had good stability. The co-catalytic mechanism of Mo powder was determined using X-Ray Diffraction, Scanning Electron Microscope, and X-ray Photoelectron Spectroscopy. The effects of different inorganic anions on AO7 were discussed: Cl − and NO 3 − had little effect on degradation, while SO 4 2− and HCO 3 − both inhibited the removal of AO7 from the system to different degrees, with HCO 3 − showing a greater inhibition than SO 4 2− . The main active radicals were identified as sulfate radical (SO 4 ·− ) and hydroxyl radical (·OH). In addition, intermediates were identified, and the attack sites were determined by combining the highest occupied molecular orbital/lowest unoccupied molecular orbital energy levels and the Fukui index to hypothesize the degradation pathways. Toxicity indicators such as the mutagenicity of AO7 and intermediates were evaluated, and the overall trend of toxicity was decreasing. This study is expected to provide an efficient treatment process for dye wastewater.
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
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Kangmeng Zhu,Xisong Wang,Dong Chen,Wei Ren,Heng Lin,Hui Zhang
Wood-based biochar, as a metal-free heterogeneous activator of peroxydisulfate (PDS), was successfully prepared by pyrolysis of polar sawdust for efficient removal of Acid Orange 7 (AO7). The results demonstrate PDS could be effectively activated by wood-based biochar, and AO7 was rapidly eliminated in a wide range of pH value (3.0–10.0) with AO7 removal achieved ≥ 99.3% after 14 min reaction. The dominant reactive species in the biochar/PDS system were verified via radical quenching tests and electron paramagnetic resonance (EPR) technique. It is speculated that sulfate radicals (SO 4 •− ) and hydroxyl radicals ( • OH) were formed on the surface of biochar. Based on the results of X-ray photoelectron spectroscopy (XPS), π-electron density and oxygen-containing functional groups (especially C–OH) on biochar surface were active centers for the catalytic reaction. Recycle experiments of biochar for 4 runs were carried out and the regeneration method of the catalyst was also studied.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Minghua Nie,Wenjing Zhang,Caixia Yan,Wenli Xu,Leliang Wu,Yuping Ye,Yun Hu,Wenbo Dong
In this study, a favorable CO 3 2− /PMS system for efficient degradation of organic contaminants (acid orange 7 (AO7), acetaminophen, para -aminobenzoic acid, phenol, methylene orange, methylene blue) in water was firstly reported. Under optimal conditions, the decolorization ration of AO7 was 100% within 40 min. Data fitting showed that the AO7 decolorization could be described by the pseudo-first-order kinetics, and the rates constant values ranging from 0.0006 to 0.2297 min −1 depending on the operating parameters (initial PMS, CO 3 2− , AO7 concentrations). Radical scavenging studies revealed that superoxide anion radical (O 2 − ) and singlet oxygen ( 1 O 2 ) rather than sulfate (SO 4 − ) nor hydroxyl (HO ) were the dominant oxidants might be responsible for AO7 degradation. The presence of NO 3 − , HPO 4 2− and low concentration of Cl − , NO 2 − , HCO 3 − , H 2 PO 4 − , HA had no significantly effect on the decolorization of AO7. Adding a higher Cl − concentration displayed favorable effects on the removal efficiencies of AO7, but adding a higher NO 2 − , HCO 3 − , H 2 PO 4 − and HA concentration apparently inhibited this process. The decolorization of AO7 was lower in wastewater in comparison to other natural waters and ultrapure water, which was probably due to the presence of higher concentration of colloids in wastewater. Nevertheless, up to 94.8%, 97.0% and 85.1% of AO7 were degraded from the filtrate, permeate, and retentate phases of wastewater within 60 min, respectively. Consequently, CO 3 2− /PMS would be promising for removal methodology for AO7 in wastewater containing considerable colloids. Finally, three intermediates were identified and degradation pathways of AO7 were proposed.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2021
·
IF 4.464
Aiyuan Li,Jiaqi Weng,Xinmei Yan,Hao Li,Haibo Shi,Xuedong Wu
This study compares the electrochemical oxidation of acid orange 74 (AO 74), a typical metal complex azo dye, on four anode materials (Ru, IrO 2 , PbO 2 , and boron doped diamond (BDD)). The results show that the BDD electrode was quite efficient in the anodic oxidation of AO 74 with a 100% removal of AO 74 and an 84.3% removal of COD. Analyzing the active species at different electrodes, we reported that oxidation on an inert electrode primarily depends on direct oxidation and indirect oxidation of active radicals ( OH and O 2 − for the BDD anode and OH for the PbO 2 anode), whereas active electrodes (Ru and IrO 2 ) primarily depend on direct oxidation. The UV–vis spectrum demonstrated that Cr 3+ could be oxidized only on the BDD anode, proving that the BDD electrode has the highest oxidation potential. Similar organic intermediates species were observed on different electrodes by GC–MS. Furthermore, the different organic products are attributed to the difference in the oxidation ability of the electrodes. From the UV–vis spectrum and GC–MS analysis, we speculate that AO 74 was first degraded to aromatic compounds and pyrazole because of the cleavage of the azo-bond. Then it formed amides and organic acid because of the cleavage of the benzene ring, and finally CO 2 and H 2 O were formed.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
高影响因子
International Journal of Environmental Research and Public Health
·
2017
·Vol. 15
·期 1
·35
·
IF 2.101
Shixiong Sheng,Bo Liu,Xiangyu Hou,Bing Wu,Fang Yao,Xinchun Ding,Lin Huang
This study investigated the biodegradation performance and characteristics of Sudan I and Acid Orange 7 (AO7) to improve the biological dye removal efficiency in wastewater and optimize the treatment process. The dyes with different water-solubility and similar molecular structure were biologically treated under aerobic condition in parallel continuous-flow mixed stirred reactors. The biophase analysis using microscopic examination suggested that the removal process of the two azo dyes is different. Removal of Sudan I was through biosorption, since it easily assembled and adsorbed on the surface of zoogloea due to its insolubility, while AO7 was biodegraded incompletely and bioconverted, the AO7 molecule was decomposed to benzene series and inorganic ions, since it could reach the interior area of zoogloea due to the low oxidation-reduction potential conditions and corresponding anaerobic microorganisms. The transformation of NH3-N, SO42−together with the presence of tryptophan-like components confirm that AO7 can be decomposed to non-toxic products in an aerobic bioreactor. This study provides a theoretical basis for the use of biosorption or biodegradation mechanisms for the treatment of different azo dyes in wastewater.Keywords:azo dye;aerobic biodegradation;Acid Orange 7;Sudan I;solubility
研究领域:
环境科学
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生物学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 2
·1172-1181
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IF 3.361
Bo Zhou,Yuling Tang,Liming Zhao,Lijun Guo,Jianfei Zhou
The removal of anionic dyes from wastewater has attracted global concern. In this work, a novel Fe3O4–poly(methacryloxyethyltrimethyl ammonium chloride) (Fe3O4–pDMC) adsorbent for the efficient removal of anionic dyes from wastewater was successfully synthesized by grafting methacryloxyethyltrimethyl ammonium chloride (DMC) on the surfaces of Fe3O4. Various characterization analyses confirmed that the obtained Fe3O4–pDMC possessed numerous functional groups on its surfaces and retained good magnetic separation properties. Fe3O4–pDMC showed ultrafast removal for acid orange 7 (AO7, 58.6%, 1 min) and direct blue 15 (DB15, 98.1%, 1 min), and the maximum adsorption capacity was high (266.8 and 336.5 mg g−1 for AO7 and DB15, respectively). In addition, the adsorption process was in accordance with pseudo-second-order kinetics and the Langmuir isotherm. The mechanism underlying the adsorption of Fe3O4–pDMC on anionic dyes was mainly dependent on electrostatic interaction. This study illustrated that Fe3O4–pDMC has great potential applications as an environmentally friendly, desirable adsorbent for the efficient removal of anionic dyes from wastewater.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
ENVIRONMENTAL ENGINEERING SCIENCE
·
2021
·Vol. 38
·期 12
·1149-1157
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IF 1.907
Zhimeng Zhang,Yuqin Wang,Feng Jiang,Qingjing Liu,Di Lang
Fenton reaction is extensively used in wastewater treatment to produce •OH, which can be used to remove organic pollutants excellently. However, the greatest issue of the process is the low efficiency of Fe2+/Fe3+ conversion cycle and hydrogen peroxide (H2O2) decomposition rate (<30%). In this study, molybdenum disulfide (MoS2) was used as a co-catalyst in Fenton system to accelerate the oxidation of acid orange 7 (AO7) dye. The enhanced removal efficiency was attributed to that the unsaturated S atoms on the surface of MoS2 could capture the protons in solutions and turn into H2S, exposing the active sites with reducibility and accelerating the conversion of Fe2+/Fe3+. A high degradation rate of 98% was obtained in 30 min under the optimal conditions of AO7 concentration 100 mg/L, MoS2 6 g/L, FeSO4·7H2O 50 mg/L, H2O2 concentration 1.5 mmol/L, and pH 3.5. Furthermore, the degradation pathway and mechanism of AO7 were thoroughly discussed. The toxicity of the intermediates during the degradation progress slightly increased initially, which then decreased to nontoxicity. MoS2 can keep stable, which can maintain high AO7 removal efficiency even after being reused for seven times. Moreover, the obtained results provide a theoretical basis and guidance for the application of inorganic co-catalyst in practical wastewater remediation applications.
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
RSC Advances
·
2018
·Vol. 8
·期 8
·3934-3940
·
IF 2.936
Chunyong Zhang,Wei Chen,Jiahui Xian,Degang Fu
In this work, a novel definitive screening design (DSD) was initially used to investigate the in situ chemical oxidation of acid orange-II (AO II) dye using a homogeneous cobalt-catalyzed peroxymonosulfate (Co2+/PMS) system. Experiments were performed in a batch reactor using a synthetic AO II solution containing cobalt ions, humic acid (HA) and five electrolyte salts (NaCl, NaNO3, NaHCO3, Na2SO4 and NaH2PO4). The effects of nine operating variables on AO II degradation: NaCl concentration (0–20 mM), NaH2PO4 concentration (0–20 mM), NaHCO3 concentration (0–20 mM), NaNO3 concentration (0–20 mM), Na2SO4 concentration (0–20 mM), HA concentration (0–40 mg L−1), PMS concentration (2–10 mM), AO II concentration (0–100 mg dm−3) and Co2+ concentration (0–1.36 mM), were investigated. Analysis of a DSD model revealed that only four variables were statistically significant. Besides, our results indicated that there were no significant interactive effects between the five anions employed. Thereafter, a central composite rotatable design (CCRD) was adopted to further optimize these significant variables. A CCRD model describing AO II conversion as a function of PMS concentration, NaCl concentration and Co2+ concentration was then constructed and used to explore the final optimal operating conditions. As a consequence, the combination of DSD and CCRD allowed reducing the number of experiments from over 600 to only 39. Lastly, a plausible reaction sequence concerning the oxidation of AO II in the Co2+/PMS/Cl− system was also proposed. The route of AO II oxidation involved hydroxylation and chlorination, signifying the roles of both sulfate radicals and active chlorine species.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Jing Li,Kangmeng Zhu,Ruimeng Li,Xiaohui Fan,Heng Lin,Hui Zhang
Granular activated carbon (GAC) was used as catalyst for the activation of peroxydisulfate (PDS) to decolorize and degrade Acid Orange 7 (AO7) in water. EPR spectra and radical quencher experiments were employed to identify the active species for AO7 oxidation in the PDS/GAC system. Linear sweep voltammetry (LSV) and chronoamperometry test were carried out to identify the contribution of nonradical mechanism for AO7 decay. The investigation of crucial operational parameters on the decolorization indicated 100 mg/L AO7 can be almost totally decolorized in a broad range of pH. Common inorganic anions adversely affect the AO7 decolorization process and the inhibition was in the order of: HCO 3 − > H 2 PO 4 − > SO 4 2− > Cl − > NO 3 − . UV–vis spectra showed the destruction of the aromatic moiety of AO7 molecule during the oxidation reaction of the PDS/GAC system. The transformation of nitrogen related to the azo bond in AO7 molecule in this system was observed by monitoring the released N-containing inorganic ions. Recycle experiments showed GAC cannot be reused directly but its catalytic ability can be restored by using electrochemical method .
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
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