Environmental Progress & Sustainable Energy
·
2012
·Vol. 32
·期 3
·564-568
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IF 1.649
Wei-guo Pan,Rui-tang Guo,Xiao-bo Zhang,Jian-xing Ren,Qiang Jin,Hong-jian Xu
The absorption process of NO into KMnO 4 /(NH 4 ) 2 CO 3 solutions was studied in a stirred tank reactor. The experimental results showed that the reaction process was a fast pseudo-m reaction. The reaction between NO and aqueous solutions of KMnO 4 /(NH 4 ) 2 CO 3 was found to be first-order with respect to NO and with respect to KMnO 4 . The frequency factor and the average activation energy of this reaction were 2.3 × 10 9 m 3 /(mol s) and 36.77 kJ/mol, respectively. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 564–568, 2013
研究领域:
环境科学
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化学工程
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CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2020
·Vol. 99
·期 3
·778-788
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IF 1.687
Chenhua Shu,Feng Zhu,Xianhong Zhu,Faying Lai
In order to improve sulphur removal efficiency, deep eutectic solvent (DES) is first introduced into the fuel oil desulphurization process with sodium borohydride (NaBH 4 ). Thereby, a novel method for fuel oil desulphurization by extraction coupled with reduction is proposed, where DES is used as stabilizer and extractant and NaBH 4 is used as reducing agent. The nickel borides produced from NaBH 4 and nickel salts were characterized using a particle size analyzer, surface area analyzer, and transmission electron microscopy. The results show that the nickel borides produced in DES have smaller particle sizes and a higher BET surface area than that in methanol/tetrahydrofuran (MeOH/THF). Sulphur removal efficiency using DES as medium was higher than that using MeOH/THF as medium. The effect of process parameters on the sulphur removal efficiency was investigated by orthogonal experiments. The results showed that the sulphur removal efficiency of dibenzothiophene can reach more than 96%. The desulphurization of dibenzothiophene should proceed over the cleavage of C−S bond to biphenyl and desulphurization reaction followed the pseudo-first-order reaction. The structures of the DESs remained unchanged after regeneration. In summary, the novel desulphurization method is feasible and promising.
研究领域:
化学工程
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环境科学
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燃料处理
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International Journal of Greenhouse Gas Control
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2018
·
IF 4.078
Yanru Chen,Wusan Jiang,Xiao Luo,Yangqiang Huang,Bo Jin,Hongxia Gao,Wensheng Li,Zhiwu Liang
In this work, the stopped-flow technique is used to determine the kinetics data in terms of pseudo first-order rate constants ( k 0 ) for the homogenous reaction of CO 2 into aqueous solutions of 3-dimethylaminopropylamine (DMAPA) and 3-diethylaminopropylamine (DEAPA) as amine concentrations ranged from 0.05 kmol/m 3 to 0.15 kmol/m 3 and temperature ranged from 293 K to 313 K. It is found that k 0 increased with increasing temperature and with increasing amine concentration. The mechanism of the pseudo first-order chemical reaction hypothesis is applied to interpret the experimental data. The Arrhenius expressions as k 2 = 8.69 × 10 9 × exp ( − 4226.2 / T ) for DMAPA and k 2 = 7.21 × 10 12 × exp ( − 6162.9 / T ) for DEAPA are obtained. The results show that the experimental CO 2 absorption rates exhibited good agreement with predicted CO 2 absorption rates with an average relative deviation (ARD) of 2.34% and 7.53%, respectively. Finally, the interaction of tertiary amine groups with primary amine groups and the effect of molecular structure on the interaction are discussed by comparing the CO 2 absorption and desorption performances in five different systems (MEA, DEEA, MEA + DEEA, DMAPA, DEAPA). It is found that the intermolecular interaction of amino groups is stronger than that of intramolecular interaction.
研究领域:
化学工程
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环境科学
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
·
IF 3.141
Rui Zhang,Wusan Jiang,Zhiwu Liang,Xiao Luo,Qi Yang
The CO2 reaction rate in aqueous 2-methylpiperazine (2MPZ) solution was investigated in terms of the pseudo-first-order rate constant (k0) by using a stopped-flow apparatus with amine concentration ranges of 0.05–0.125 mol/L and the measuring temperature ranges of 293.15–313.15 K. The results show that the CO2 reaction rate in the 2MPZ solution increased as the temperature and the amine concentration increases. The results also demonstrate that the 2MPZ has a faster reaction rate in terms of k0 than 3-dimethylaminopropylamine, 3-diethylaminopropylamine, and monoethanolamine (MEA) but slower than that of PZ at the same amine concentration. The equilibrium solubility as an important absorption parameter for CO2 capture also were measured at 298.15, 313.15, and 333.15 K with CO2 partial pressures of 5–100 kPa, respectively, in 2 M 2MPZ solution. The results show that the CO2 equilibrium solubility of 2MPZ increased as the CO2 partial pressure increased but decreased as the temperature increased. The heat of CO2 absorption in 2 M 2MPZ solution was estimated by using the Gibbs–Helmholtz equation, and the value (−70.9 kJ/mol) is similar to that of PZ but lower than that of MEA. Besides the conclusions stated above, the results of the 13C NMR quantitative investigation suggest that 2MPZ can produce less carbamate and more bicarbonate than PZ at the same CO2 loading.
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化学工程
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环境科学
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MICROCHEMICAL JOURNAL
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2021
·
IF 4.821
Qinggong Ren,Congcong Kong,Zhihui Chen,Jiading Zhou,Weimin Li,Dongyang Li,Zhijian Cui,Yinghao Xue,Yuhan Lu
An advanced oxidation method combining ultrasonic (US) and electrochemical (EC) for degrading malachite green wastewater in batches was discovered. The performance of the system can be judged by quantitatively measuring the degradation rate of malachite green under different electrode materials, electrolytes, voltages and powers. The results show that the highest degradation of malachite green was obtained, reaching up to 94.92%, when the voltage was 20 V, ultrasonic power was 300 W and electrolyte solution was 15.0 g/L Na 2 SO 4 under the condition that the ruthenium-iridium plated titanium electrode was used as the anode and graphite as the cathode. The ultrasonic electrochemical process conforms to the characteristics of pseudo-first-order reaction kinetics. Compared with other methods, ultrasonic electrochemical method is more cost-effective and environmentally friendly. Finally, the possible degradation process of malachite green is inferred, including oxidation and N-demethylation.
研究领域:
环境科学
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废水处理
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Current Nanoscience
·
2019
·Vol. 15
·期 2
·188-196
·
IF 1.586
Xu Chengpeng,Ye Shengying,Cui Xiaolei,Zhang Quan,Liang Yan
Background: Improper storage and raw materials make peanut oil susceptible to Aflatoxin B1 (AFB1). The semiconductor TiO2 photocatalysis technology is an effective technology which is widely used in sewage treatment, environmental protection and so on. Moreover, the photocatalytic efficiency
can be improved by doping I. Method: The experiment is divided into two parts. In the first part, supported TiO2 thin film (STF) was prepared on the quartz glass tube (QGT) by the sol-gel and calcination method and the supported iodine doped supported TiO2 thin film (I-STF) was synthesized
using potassium iodate solution. In the second part, the photocatalytic degradation of AFB1 was performed in a self-made photocatalytic reactor. The AFB1 was detected by ELISA kit. Results: The photocatalytic degradation of AFB1 has been proven to follow pseudo first-order reaction kinetics
well (R2 > 0.95). The maximum degradation rate of 81.96%, which was reached at the optimum iodine concentration of 0.1mol/L, was 11.38% higher than that with undoped STF. Conclusion: The doping of iodine reduces the band-gap of TiO2, thereby increasing the photocatalytic response range.
The proportion of Ti4+ in I-STF has decreased, which means that Ti4+ are replaced by I. The I-STF prepared at iodine concentration of 0.1mol/L has good photocatalytic properties.
研究领域:
食品安全
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环境科学
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材料科学
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化学工程
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高影响因子
Reaction Kinetics Mechanisms and Catalysis
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2024
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IF 1.7
Liu Zhi,Xie Shiwei,Xiao Tian,Fang Chengyi,Liu Xixiang,Liu Yan
In this study, Ti-Sn-Sb/γ-Al 2 O 3 particle electrodes were prepared by sol–gel method and a three-dimensional electrocatalytic system was constructed to treat methylene blue (MB) dye wastewater. The experimental results demonstrate that the degradation of methylene blue conforms to the pseudo-first order reaction kinetics and had a low activation energy (E a = 36.97 kJ/mol). Through quenching experiments, linear voltammetry tests, and radical trapping experiments utilizing benzoic acid as a probe, we have determined that the oxidation of MB by the particle electrode is primarily induced through direct surface electron transfer (86 ~ 88%) and surface-bound radicals (12 ~ 14%). Graphical abstract Methylene blue undergoes degradation through the synergistic interplay of direct electron transfer (86% ~ 88%) and surface-bound radicals ·OH ads (12% ~ 14%) on the particle electrode’s surface.
研究领域:
环境科学
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电化学
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废水处理
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Journal of Environmental Chemical Engineering
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2023
·
IF 7.7
Kang Hoon Lee,June Young Kim,Imtiaz Afzal Khan,Jae Won Lee,Jong-Oh Kim
This study aimed to optimize the ultraviolet (UV)/hydrogen peroxide (H 2 O 2 ) process for degrading chemicals of emerging concern (CECs), such as caffeine (CAF), atenolol (ATL), acetaminophen (ACT), and chlortetracycline (CTC). The CECs used in this study were chosen because they are used in various industries, affect water bodies, and are difficult to degrade using conventional oxidation and biological processes. The individual degradation results revealed that the CAF degradation rate increased from 23 ± 2%–80 ± 4% as the UV/H 2 O 2 dose increased from 1 to 10 mg·L −1 . Similarly, the ATL, ACT, and CTC degradation rates increased from 59.23 ± 2%, 34.21 ± 1.9%, and, 41.36 ± 2.3%–91.24 ± 3%, 68.12 ± 3%, and 91.93 ± 3.1%, respectively. The complex feed water analysis results revealed that CTC had a higher degradation rate than the other targeted contaminants owing to its higher degradation potential. The rate of reaction results revealed that the degradation of these CECs followed the pseudo-first-order reaction, with R 2 > 0.95 in all cases. liquid chromatography with tandem mass spectrometry (LC–MS/MS) was used to identify the degradation products , and the results revealed the presence of low-molecular-weight organic products due to oxidation. The organic products were formed because of the hydroxylation and demethylation of intermediates and photoproducts, which caused a ring opening and generated several low-molecular-weight carboxylic acids before complete mineralization. These results illustrate that the UV/H 2 O 2 process had some significant effects on the complex mixture. However, CTC exhibited a relatively high degradation rate, which is believed to have inhibited the degradation of other chemicals.
研究领域:
环境科学
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水处理工程
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JOURNAL OF HAZARDOUS MATERIALS
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2019
·
IF 7.65
Lei Xu,Xiao Ma,Junfeng Niu,Jie Chen,Chengzhi Zhou
The kinetics and mechanisms of naproxen (NPX) degradation with the concentration of 20–200 μg/L were investigated by using reactive flow-through membrane anode. The electrochemical degradation of NPX followed pseudo-first-order reaction kinetics. The kinetic rate constant ( k ) of 0.649 min –1 and energy consumption ( E EO ) of 0.744 Wh/L were found under optimal conditions with the initial NPX concentration of 50 μg/L. Higher current density benefited •OH production and NPX degradation. Faster rotational speed of pump and lower pH were in favor of electrochemical degradation of NPX, in which k and E EO were 3.9 and 0.27 times when rotational speed was increased from 100 to 600 rpm, and 4.9 and 0.21 times when pH was decreased from 11.0 to 3.0, respectively. The degradation efficiency and energy consumption were both maintained at a narrow range when the initial concentration of NPX was changed from 20 to 200 μg/L, and even under the addition of humic acid (1.0–10.0 mg/L). The major degradation pathways of NPX were demethylation and decarboxylation, followed with the further ring cleavage reactions. The flow-through membrane electrode is proved to be effective for the elimination of trace NPX from aqueous solution.
研究领域:
环境工程
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水处理
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电化学
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制药废物管理
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Fei Yan,Xiaohan Guo,Qingying Ye,Ping Li,Juanjuan Qi,Lidong Wang
Due to its excellent solubility for many chemicals, DMSO is widely used as solvents in industries. The biodegradation of DMSO is pretty slow and gives out noxious and volatile compounds like dimethylsulfide, methyl mercaptan, and hydrogen sulfide. Therefore, a green and efficient DMSO removal process is needed. In this work, supported molybdenum oxide catalysts were prepared and were characterized with powder XRD, SEM, TEM, Raman, DR-UV–vis spectroscopy and XPS. These catalysts are efficiently active for the catalytic oxidation of DMSO in wastewater using green oxidant, H 2 O 2 . The degradation product of DMSO is DMSO 2 which is an environmentally friendly and biodegradable compound and can be further removed by biological processes without forming hazardous sulfides. Fumed SiO 2 is the best support for MoO 3 and the catalytic activity increases with the increase of the MoO 3 loading. DMSO (179 mmol/L) is completely removed after a 2-hour reaction at 50 °C. EPR analyses and control experiments with radical scavengers confirm that the oxidative degradation of DMSO is not a radical reaction. Thus, a non-radical oxidation mechanism is proposed for the degradation of DMSO. The kinetic study on the 30 wt% MoO 3 /SiO 2 catalyst confirms that the catalytic oxidation reaction of DMSO is a pseudo-first-order reaction with an apparent activation energy of 68.5 kJ/mol. When the initial concentration of DMSO is further increased to 264 or 344 mmol/L, the MoO 3 /SiO 2 catalyst can still remove it within 2 h. In conclusion, this catalyst is a promising candidate for treating industrial wastewater containing DMSO.
研究领域:
环境科学
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催化
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化学工程
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废物管理
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高影响因子
CHEMOSPHERE
·
2017
·
IF 4.208
Xiaohua Ren,Huanhuan Guo,Jinkui Feng,Pengchao Si,Lin Zhang,Lijie Ci
3D porous N-doped reduced graphene oxide (N-rGO) aerogels were synthesized by a hydrothermal reduction of graphene oxide (GO) with urea and following freeze-drying process. N-rGO aerogels have a high BET surface of 499.70 m 2 /g and a high N doping content (5.93–7.46 at%) including three kinds of N (graphitic, pyridinic and pyrrolic). Their high catalytic performance for phenol oxidation in aqueous solution was investigated by catalytic activation of persulfate (PS). We have demonstrated that N-rGO aerogels are promising metal-free catalysts for phenol removal. Kinetics studies indicate that phenol degradation follows first-order reaction kinetics with the reaction rate constant of 0.16799 min −1 for N-rGO-A(1:30). Interestingly, the comparison of direct catalytic oxidation with adsorption-catalytic oxidation experiments indicates that adsorption plays an important role in the catalytic oxidation of phenol by decreasing the phenol degradation time. Spin density and adsorption modeling demonstrates that graphitic N in N-rGO plays the most important role for the catalytic performance by inducing high positive charge densities to adjacent carbon atoms and facilitating phenol adsorption on these carbon sites. Furthermore, the activation mechanism of persulfate (PS) on N-rGO was first investigated by DFT method and PS can be activated to generate strongly oxidative radical (SO 4 · - ) by transferring electrons to N-rGO.
研究领域:
环境科学
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催化
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材料科学
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化学工程
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PubMed
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-11
·
IF 14.7
Xiao Qian,Li Wanbin,Xie Shujie,Wang Li,Tang Chuyang Y.
Chlorinated organic pollutants widely exist in aquatic environments and threaten human health. Catalytic approaches are proposed for their elimination, but sluggish degradation, incomplete dechlorination, and catalyst recovery remain extremely challenging. Here we show efficient dechlorination using ferrous oxide/graphene oxide catalytic membranes with strong nanoconfinement effects. Catalytic membranes are constructed by graphene oxide nanosheets with integrated ultrafine and monodisperse sub-5 nm nanoparticles through simple in-situ growth and filtration assembly. Density function theory simulation reveals that nanoconfinement effects remarkably reduce energy barriers of rate-limiting steps for iron (III)-sulfite complex dissociation to sulfite radicals and dichloroacetic acid degradation to monochloroacetic acid. Combining with nanoconfinement effects of enhancing reactants accessibility to catalysts and increasing catalyst-to-reactant ratios, the membrane achieves ultrafast and complete dechlorination of 180 µg L −1 dichloroacetic acid to chloride, with nearly 100% reduction efficiency within a record-breaking 3.9 ms, accompanied by six to seven orders of magnitude greater first-order rate constant of 51,000 min −1 than current catalysis. Meanwhile, the membranes exhibit quadrupled permeance of 48.6 L m −2 h −1 bar −1 as GO ones, because nanoparticles adjust membrane structure, chemical composition, and interlayer space. Moreover, the membranes show excellent stability over 20 cycles and universality for chlorinated organic pollutants at environmental concentrations.
研究领域:
环境科学
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催化
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纳米技术
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水处理
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PubMed
高影响因子
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