JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING
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2011
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IF 1.107
Zhiqiao He,Angliang Zhang,Yu Li,Shuang Song,Zhiwu Liu,Jianmeng Chen,Xinhua Xu
Ozonation combined with UV irradiation (UV/O3) is an advanced oxidation technique that is very promising for the destruction of organic compounds in aqueous solution. In this study, chlorophene was chosen as a model substrate to investigate the effects of pH, initial substrate concentration, ozone dose, and UV light intensity in degradation experiments. The pseudo–first-order rate constant for total organic carbon (TOC) removal was 2.4 × 10−2, 9.8 × 10−4, and 6.4 × 10−2 min−1 for O3, UV, and UV/O3 treatment, respectively. Clearly, UV-enhanced ozonation leads to a synergetic increase in the overall degradation efficiency. Comparative experiments were performed to investigate the effect of the matrix (distilled water or sewage) on chlorophene removal. The organic compounds in sewage retarded the rate of chlorophene removal by 38%, probably by competitively reacting with the oxidizing agent and screening light. The compound 2-benzoylbenzo-1,4-quinone, benzo-1,4-quinone, hydroquinone and maleic acid were identified as primary intermediates by gas chromatography-mass spectrometry. The concentrations of acetic, formic and oxalic anions were detected by ion chromatography. A possible degradation pathway is proposed on the basis of the reaction products identified.
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
JOM
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2020
·Vol. 72
·期 11
·3887-3894
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IF 2.054
Pang Zhongya,Zou Xingli,Tang Wei,Shi Tianyu,Wang Shujuan,Ji Li,Hsu Hsien-Yi,Xu Qian,Lu Xionggang
Carbide-derived carbon (CDC) as an unconventional porous carbon material has been widely used for various applications. In this work, Ti 3 AlC 2 -derived porous carbon (Ti 3 AlC 2 -CDC) was electrochemically synthesized at 900°C and 3.0 V in molten CaCl 2 -NaCl. The obtained Ti 3 AlC 2 -CDC with abundant slit-like mesopores showed a high specific surface area of 425 m 2 /g. The variation of the morphology from the Ti 3 AlC 2 precursor to Ti 3 AlC 2 -CDC was investigated, with the Ti 3 AlC 2 -CDC demonstrating a typical loose layered morphology and amorphous carbon structure. The intermediate products were also systematically analyzed to investigate the molten salt electrochemical etching process. It was found that Ti 3 AlC 2 can be oxidized by residual O 2− in the molten salt to form tiny Al 2 O 3 particles on the anodic Ti 3 AlC 2 surface during the etching process, then Ti 3 AlC 2 -CDC can be obtained by successively removing these Al 2 O 3 , Al, and Ti from the Ti 3 AlC 2 precursor.
研究领域:
材料科学
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电化学
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纳米材料
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能源材料
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表面工程
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Zhengkang Peng,Xun Gong,Zijian Zhou,Shiwei Dong,Wei Hu,Hanxiao Liu,Jingying Xu
The removal of naphthalene is important but deficient, so that the available V-W/Ti catalysts (1.0 wt% V 2 O 5 /TiO 2 ) were prepared for its efficient abatement in this work. Especially, influences of different existence status of vanadium species on naphthalene elimination were investigated via changing the pH value of precursor solution. With the increase of precursor solution acidity, more highly polymeric vanadium species were formed on the catalyst surface. The redox capability was enhanced markedly as a consequence of the stronger electron transfer between V/W and Ti that induced more surface active oxygen and V 5+ , whereas the catalytic activity was obviously boosted and almost 90 % conversion of naphthalene was achieved at 293 °C. Moreover, the weaker chemisorption between naphthalene and V-W/Ti catalyst allowed the deeper conversion to CO x . GC–MS manifested that naphthalene seemed to be an organic component that was difficult to be totally degraded. Naphthalene oxidation was in the following pathway of naphthalene → 1,4-naphthoquinone → phthalic anhydride → phthalates → benzene → benzoquinone → maleic anhydride → CO x /H 2 O. The opening of aromatic ring in phthalic anhydride and benzene ring in benzene were proven to be the rate-controlling step based on in-situ DRIFTS results. The key of naphthalene oxidation was the complete degradation of various intermediates.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
CHEMOSPHERE
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2020
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IF 5.778
Nan Yang,Yanping Liu,Jia Zhu,Zhongqiang Wang,Jinwei Li
In order to improve the catalytic activity and recycling performance of heterogeneous Fenton catalyst, a heterogeneous Fenton catalyst Fe/TiO 2 based on TiO 2 supported visible light response was prepared by a simple method using TiO 2 synthesized by sol-gel method as carrier and ferric nitrate as Fe source. It was characterized by SEM , EDX , XRD, UV–vis instruments. The influencing factors of catalytic degradation of atrazine by visible light heterogeneous Fenton of Fe/TiO 2 were studied and the reaction kinetics were fitted. The mineralization degree of atrazine was reflected by the removal rate of TOC. The intermediate products by the degradation of the catalytic system was analyzed and the reaction mechanism of Fe/TiO 2 –H 2 O 2 visible light system was discussed. The XRD results showed that Fe was highly dispersed on the surface of TiO 2 in the form of α-Fe 2 O 3 . The Fe/TiO 2 catalyst with heterogeneous Fenton and visible light photocatalytic activity was successfully optimized, forbidden bandwidth of Fe/TiO 2 after Fe supported was narrower, the scope of light absorption red-shifted, the electron-hole pairs were more generated, and there was a significant synergistic effect between the carrier TiO 2 and the supported Fe, which exhibited good oxidation capacity for degradation of 10 mg L −1 atrazine in pH of 3, the concentration of H 2 O 2 was 1.6 mM, and the catalyst was added at 1 g L −1 , achieving over 95% removal efficiency within 30 min, and, in the range of pH 3–7, the degradation rate of the reaction for 30 min can be maintained above 75%, which greatly broadened the range of pH application and had good recycling performance. The degradation process conformed to the quasi-first-order kinetic model . Through LC-MS analyzed, 12 intermediate products were formed during the degradation of atrazine, the final products were all cyanuric acid, and then the triazine ring was mineralized into inorganic substances such as CO 2 , H 2 O and NO 3 − by oxidation of ·OH, and the possible degradation pathways were inferred.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
CHEMOSPHERE
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2018
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IF 4.427
Yihan Zhang,Jing Shi,Zhengwen Xu,Yue Chen,Duanmei Song
Schorl could perform as an extremely promising catalyst for decomposing tetracycline hydrochloride (TC) due to its high degradation efficiency, low cost, chemical stability, easy recovery and repeatable utilization. Comparisons of TC degradation indifferent systems showed that schorl/H 2 O 2 system exhibited the optimum pollutant elimination and TOC removal efficiencies. Kinetics and possible mechanisms of TC degradation were clarified. The OH generated on the schorl surface and O 2 − /HO 2 were the main reactive species responsible for TC oxidation. Six possible intermediates were identified, and possible transform mechanisms and pathways were explored. Active radicals were inclined to attack the C C double bond, dimethylamino and phenolic moieties of TC molecular. The principal intermediate products were generated through N-demethylation, oxidation and rearrangement.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2020
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IF 4.966
Wei Wang,Junmei Tian,Zhijia Zhu,Chenmiao Zhu,Baojiang Liu,Chunyan Hu
A facile, efficient, precise and reliable method based on liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established to separate and determine two typical quinolone antibiotics (ofloxacin and lomefloxacin) and two typical sulfonamide antibiotics (sulfadimeisoxazole and sulfadimidine). The photocatalytic degradation effects, identification of intermediate products and decomposition pathways of these four antibiotics degraded by Bi 2 MoO 6 /Bi 2 WO 6 /MWCNTs composite catalyst were analyzed using the developed HPLC-MS/MS method. It was found that all four antibiotics can be synchronously decomposed with the ultrahigh removal rates of above 95 %. Three main degradation reactions of quinolones were detected: the decarboxylation of quinolones, the ring opening reaction of piperazine and the defluorination of C–F. The main decomposition reactions of sulfonamides included the sulfonamide bond (S N) breaking at the active sites, the oxidation of the amino acids on the benzene rings , and the substitution and oxidation ring opening reaction of pyrimidine. This study not only developed a detailed isolation and identification method for the degradation pathways and mechanisms of mixed pharmaceutical pollutants, but also provides a superb photocatalyst for the removal of multiplex pharmaceutical pollutants.
研究领域:
环境科学
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分析化学
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药理学
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DOI
高影响因子
Journal of Cleaner Production
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2020
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IF 7.246
Juan Lv,Yan Wang,Mengya Fu,Changyuan Ou,Fan Xiao
Tetramethylammonium Hydroxide (TMAH) is widely used as a developer in the thin-film transistor liquid crystal display (TFT-LCD) industry, which is a corrosive alkaline and neuronal toxic compound. In this study, the performances of combined hydrolysis acidification-aerobic and anaerobic batch reactors for synthetic TMAH wastewater treatment were evaluated. It also investigated the real TMAH wastewater treatment in the anaerobic batch reactor. The batch tests focused on the removal efficiencies and intermediate products of TMAH biodegradation during different processes. Furthermore, microbial community structures were identified. The long-term monitoring of 380 days results demonstrated that TMAH degraded can be stably achieved by hydrolysis acidification-aerobic and anaerobic processes , and the total organic carbon removal efficiencies were both higher than 91%. The pretreatment by hydrolysis acidification process could avoid the inhibition of high concentration TMAH on subsequent aerobic treatment . Main intermediate products during the hydrolysis acidification-aerobic and anaerobic treatments included trimethylamine, dimethylamine, monomethylamine, which can be degraded easily by biotreatment . Consequently, nearly 70% organic nitrogen in the influent TMAH transferred to ammonium or nitrate, while the mineralization of intermediates caused methane and carbon dioxide generation. The study also proposed TMAH degradation pathways by different processes based on the intermediate’s identification. Analysis of 16s rRNA gene sequencing revealed that mixed microbe contributed in TMAH degradation. At the phylum level, proteobacteria and bacteroidetes were abundant in all the reactors. Besides, patescibateria , cloacimonetes and acidobacteria were dominant in anaerobic reactors as well. This study suggests that traditional combined or single activated sludge processes could be used for TMAH-containing wastewater treatment. Especially, anaerobic process may be favored over other processes.
研究领域:
环境科学
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生物学
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DOI
高影响因子
CHEMOSPHERE
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2022
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IF 8.943
Hang Liu,Yuan Meng,Jie Li,Xiaohui Wang,Tingting Zhang
The pseudo-persistence of pharmaceutical and personal care products (PPCPs)in the aqueous environment may pose potential risks to human health and ecosystems. The UV disinfection in wastewater treatment plants is one of the essential processes before PPCPs enter the water environment, so it is crucial to elucidate the photolytic behavior and mechanism of PPCPs under UV radiation . In this work, carbamazepine (CBZ) and caffeine (CAF) were selected as typical pollutants to investigate the effect of water matrixes, humic acid , inorganic ions , and pH on the UV radiation performance. Hydroxyl radical (•OH) and singlet oxygen ( 1 O 2 ) were identified by quenching experiments and electron paramagnetic resonance (EPR) spectra as playing a dominant role in the degradation process. UPLC-TOF/MS was conducted to identify 13 and 14 possible intermediates of CBZ and CAF, respectively. Moreover, combining density functional theory (DFT) calculations (Frontier Molecular Orbital and Fukui index), hydroxylation , oxidation , and ring cleavage were proposed as the main degradation pathways of the contaminants, which occurred first at the C(7C), N(17 N) and O(18O) sites of CBZ and at the C(9C) site of CAF. The bio-acute toxicity experiment and the Ecological Structure-Activity Relationships (ECOSAR) program were performed to analyze and predict the toxicity of the intermediates of CBZ and CAF under UV radiation, respectively. The results showed that the acute toxicity of both solutions increased after UV radiation and followed with the combined toxicity. This work has great scientific value and practical environmental significance for evaluating the UV disinfection process and managing PPCPs in the aqueous environment.
研究领域:
环境科学
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毒理学
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DOI
高影响因子
CATALYSIS TODAY
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2018
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IF 4.667
Miao Lai,Jie Zhao,Qingcai Chen,Shuaijun Feng,Yujie Bai,Yingxuan Li,Chuanyi Wang
In the photocatalytic volatile organic compounds (VOCs) degradation, the accumulation of intermediate products on the surface of catalysts could cause a decrease in activity through retarding reactant (e.g. O 2 ) supply to surface active sites. Herein, Bi decorated TiO 2 photocatalysts (Bi/TiO 2 ) for photocatalytic toluene degradation were prepared and systematically studied. It is found that metallic Bi modification improves the ability of photocatalysts to capture O 2 . As a result, the activities of the Bi/TiO 2 photocatalysts are obviously higher than that of the TiO 2 for photocatalytic toluene degradation, and the productions of photogenerated reactive oxygen species ( O 2 − and H 2 O 2 ) over the Bi/TiO 2 photocatalysts are almost equal to that over the TiO 2 despite the fact that the separation efficiency of photoinduced charge carriers is decreased after the addition of Bi. Adsorbed benzaldehyde is the main surface intermediate on the surface of the Bi/TiO 2 photocatalysts, whereas plenty of more readily oxidized aliphatic carboxylate species was monitored on the surface of the TiO 2 , which can be attributed to insufficient O 2 supply to the TiO 2 surface. This further indicates the positive role of the promoted O 2 supply by Bi in the photocatalytic toluene degradation. The present work offers a new window for addressing the catalyst deactivation in the photocatalytic VOCs degradation.
研究领域:
环境催化
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大气污染控制
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材料化学
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表面科学
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光化学
✓ 已验证
DOI
高影响因子
Applications in Energy and Combustion Science
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2022
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IF 0
Bingzhi Liu,Long Zhu,Qingbo Zhu,Hao Lou,Qiang Xu,Zhandong Wang
Ozone-assisted combustion is an advanced combustion technology that is considered a promising means for the active control of combustion. Ozone addition can enhance combustion processes and extend the experimental parameters to extreme conditions. In this work, ozone-assisted low temperature oxidation of methanol and ethanol in a jet-stirred reactor (JSR) was carried out at atmospheric pressure, with a fuel initial mole fraction of 0.005, an equivalence ratio of 0.28, and in the temperature range of 330–800 K. Significant conversions of methanol and ethanol were observed in the low temperature region when ozone was added. Numerous intermediate species were analyzed and quantified by synchrotron vacuum ultraviolet photoionization mass spectrometry and gas chromatography, which are crucially important for unraveling the low temperature oxidation reaction network. The kinetic model of NUIGMech1.1 is tentatively updated to better explain the measured results, although the improvements of the C 1 –C 2 core mechanisms are difficult. Ozone addition enhances the action of the reaction channel of related radicals. Model analysis shows that the kinetics of Ö/ȮH/HȮ 2 atoms/radicals are crucial for the overall reaction progress, as well as the reaction of HȮ 2 radicals with ozone, which mainly contributes to the formation of ȮH radicals during the initial reaction stage. Inconsistency between measurements and model predictions highlights the considerable uncertainty in the C 1 -C 2 alcohols subchemistry at lower temperatures. The experimental results obtained in this work and model development will motivate further study of the low temperature oxidation chemistry of methanol and ethanol.
研究领域:
化学工程
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燃烧化学
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反应动力学
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能源化学
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大气压反应器
✓ 已验证
DOI
危险品化学品经营许可证（带存储）