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Enhanced carbon tetrachloride degradation by hydroxylamine in ferrous ion activated calcium peroxide

Wenchao Jiang, Ping Tang, Zhen Liu, Huan He, Qian Sui, Shuguang Lyu

《环境科学与工程前沿(英文)》 2020年 第14卷 第2期 doi: 10.1007/s11783-019-1197-1

摘要: Complete CT degradation was achieved by employing HA to CP/Fe(II)/FA process. Quantitative detection of Fe(II) regeneration and HO• production was investigated. Benzoic acid outcompeted FA for the reaction with HO•. CO2•− was the dominant reductive radical for CT removal. Effects of solution matrix on CT removal were conducted. Hydroxyl radicals (HO•) show low reactivity with perchlorinated hydrocarbons, such as carbon tetrachloride (CT), in conventional Fenton reactions, therefore, the generation of reductive radicals has attracted increasing attention. This study investigated the enhancement of CT degradation by the synergistic effects of hydroxylamine (HA) and formic acid (FA) (initial [CT] = 0.13 mmol/L) in a Fe(II) activated calcium peroxide (CP) Fenton process. CT degradation increased from 56.6% to 99.9% with the addition of 0.78 mmol/L HA to the CP/Fe(II)/FA/CT process in a molar ratio of 12/6/12/1. The results also showed that the presence of HA enhanced the regeneration of Fe(II) from Fe(III), and the production of HO• increased one-fold when employing benzoic acid as the HO• probe. Additionally, FA slightly improves the production of HO•. A study of the mechanism confirmed that the carbon dioxide radical (CO2•−), a strong reductant generated by the reaction between FA and HO•, was the dominant radical responsible for CT degradation. Almost complete CT dechlorination was achieved in the process. The presence of humic acid and chloride ion slightly decreased CT removal, while high doses of bicarbonate and high pH inhibited CT degradation. This study helps us to better understand the synergistic roles of FA and HA for HO• and CO2•− generation and the removal of perchlorinated hydrocarbons in modified Fenton systems.

关键词: Calcium peroxide     Hydroxylamine     Modified Fenton     Reactive oxygen species     Perchlorinated hydrocarbon    

Enhanced degradation of trichloroethene by calcium peroxide activated with Fe(III) in the presence of

Xiang ZHANG,Xiaogang GU,Shuguang LU,Zhouwei MIAO,Minhui XU,Xiaori FU,Muhammad DANISH,Mark L. BRUSSEAU,Zhaofu QIU,Qian SUI

《环境科学与工程前沿(英文)》 2016年 第10卷 第3期   页码 502-512 doi: 10.1007/s11783-016-0838-x

摘要: Trichloroethene (TCE) degradation by Fe(III)-activated calcium peroxide (CP) in the presence of citric acid (CA) in aqueous solution was investigated. The results demonstrated that the presence of CA enhanced TCE degradation significantly by increasing the concentration of soluble Fe(III) and promoting H O generation. The generation of HO? and O ? in both the CP/Fe(III) and CP/Fe(III)/CA systems was confirmed with chemical probes. The results of radical scavenging tests showed that TCE degradation was due predominantly to direct oxidation by HO?, while O ? strengthened the generation of HO? by promoting Fe(III) transformation in the CP/Fe(III)/CA system. Acidic pH conditions were favorable for TCE degradation, and the TCE degradation rate decreased with increasing pH. The presence of Cl , HCO , and humic acid (HA) inhibited TCE degradation to different extents for the CP/Fe(III)/CA system. Analysis of Cl production suggested that TCE degradation in the CP/Fe(III)/CA system occurred through a dechlorination process. In summary, this study provided detailed information for the application of CA-enhanced Fe(III)-activated calcium peroxide for treating TCE contaminated groundwater.

关键词: calcium peroxide     trichloroethene (TCE)     citric acid     ferric ion     free radicals     oxidation    

Remediation of 2,4-dichlorophenol-contaminated groundwater using nano-sized CaO in a two-dimensional scale tank

《环境科学与工程前沿(英文)》 2020年 第15卷 第5期 doi: 10.1007/s11783-020-1381-3

摘要:

• Nano CaO2 is evaluated as a remediation agent for 2,4-DCP contaminated groundwater.

关键词: Calcium peroxide     2     4-DCP     Reaction zone     Fenton reaction    

The capture of carbon dioxide by transition metal aluminates, calcium aluminate, calcium zirconate, calcium

Ganesh TILEKAR, Kiran SHINDE, Kishor KALE, Reshma RASKAR, Abaji GAIKWAD

《化学科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 477-491 doi: 10.1007/s11705-011-1107-y

摘要: The capture of CO by transition metal (Mn, Ni, Co and Zn) aluminates, calcium aluminate, calcium zirconate, calcium silicate and lithium zirconate was carried out at pre- and post-combustion temperatures. The prepared metal adsorbents were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), surface area analysis and acidity/alkalinity measurements. The different experimental variables affecting the adsorbents ability to capture CO , such as the mol ratio of metal ions, the pressure of CO , the exposure time and the temperature of the adsorbent were also investigated. Calcium zirconate captured 13.85 wt-% CO at 650°C and 2.5 atm and calcium silicate captured 14.31 wt-% at 650°C. Molecular sieves (13X) and carbon can only capture a negligible amount of CO at high temperatures (300°C–650°C). However, the mixed metal oxides captured reasonable amount of CO at these higher temperatures. In addition, calcium aluminate, calcium zirconate, calcium silicate and lithium zirconate adsorbents captured CO at both pre and post-combustion temperatures. The trend for the amount of captured carbon dioxide over the adsorbents was calcium aluminate

关键词: captured CO2     pre-combustion temperature     characterization     calcium silicate     calcium zirconate    

On corrosion to stainless steel by calcium chloride with different extender

Lv XU, Yuanyang HU, Liwei WANG, Ruzhu WANG,

《能源前沿(英文)》 2010年 第4卷 第2期   页码 181-184 doi: 10.1007/s11708-009-0065-2

摘要: A calcium chloride solution with a different extender, which is made up of either pure calcium chloride, calcium chloride with expanded graphite, or calcium chloride with activated carbon, acts differently on stainless steel. The mass ratio between calcium chloride with expanded graphite or activated carbon is almost 4∶1, which is demonstrated to be the optimum ratio. The experimental research in this paper reveals that, of the three solutions, which are pure calcium chloride, calcium chloride with expanded graphite, and calcium chloride with activated carbon, the strongest oxidation creation and pitting corrosion happened in the solution of calcium chloride with expanded graphite, the weakest oxidation creation happened in the solution of calcium chloride with activated carbon, and pitting corrosion was stronger than oxidation creation in the solution of pure calcium chloride. This paper gives the reasons for these phenomena. Furthermore, based on theory analysis, multiple means and approaches are provided to prevent stainless steel from further corroding.

关键词: stainless steel     corrosion     calcium chloride     expanded graphite     activated carbon     oxidation creation     pitting corrosion    

Reactive extraction for preparation of hydrogen peroxide under pressure

CHENG Yongxi, LI Hongtao, WANG Li, LÜ Shuxiang

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 335-340 doi: 10.1007/s11705-008-0042-z

摘要: The preparation of hydrogen peroxide from anthrahydroquinone by reactive extraction was investigated. The integration process of oxidation of anthrahydroquinone by air and extraction of hydrogen peroxide from the organic phase with water was carried out in a sieve plate column under pressure. The conversion of anthrahydroquinone increased with increasing pressure resulting in an increase of hydrogen peroxide concentration in the aqueous phase. However, no change in extraction efficiency of hydrogen peroxide was observed. A mathematical model for gas-liquid-liquid reactive extraction was established. In the model, the effects of pressure and gas superficial velocity on reaction were considered. With increasing gas superficial velocity, the conversion of anthrahydroquinone increased, and the fraction of hydrogen peroxide extracted reached a plateau with a maximum of 72.94%. However, both the conversion of anthrahydroquinone and the fraction of hydrogen peroxide extracted decreased with increasing organic phase superficial velocity.

Hydrogen peroxide is correlated with browning in peach fruit stored at low temperature

Zhansheng DING, Shiping TIAN, Xianghong MENG, Yong XU,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 363-374 doi: 10.1007/s11705-009-0246-x

摘要: The objective of this present research is to study the biological basis of browning in peach fruit during storage at low temperatures. After being immersed in 0 or 2mmol·L salicylic acid (SA) aqueous solution for 10min, peach fruit (Prunus persica L. cv. Hongtao) were stored at 10°C, 5°C or 0°C with or without shelf life at 25°C. During storage, the progress of browning, lipid per-oxidation, phenol content, activities of polyphenol oxidase (PPO, E.C. 1.14.18.1) and guaiacol peroxidase (POD, EC 1.11.1.7), redox state of ascorbate and glutathione, as well as the content, location and metabolism of hydrogen peroxide (HO) in the fruit were examined. The results indicated that a decrease in HO content was correlated with browning, whereas phenol content and activities of PPO and POD were not correlated with the change in HO content. Moreover, HO content was influenced by different responses of antioxidants at different storage conditions. It was concluded that the main effect of HO on browning was to regulate its appearance and development as a signal molecule, and lower HO content was beneficial to browning.

关键词: beneficial     per-oxidation     appearance     decrease     hydrogen peroxide    

Efficient production of hydrogen peroxide in microbial reverse-electrodialysis cells coupled with thermolytic

《环境科学与工程前沿(英文)》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1708-y

摘要:

● Appreciable H2O2 production rate was achieved in MRCs utilizing NH4HCO3 solutions.

关键词: Microbial reverse-electrodialysis cell     Hydrogen peroxide production     Ammonium bicarbonate     Electrolysis cell     Optimization    

Toward better understanding vacuum ultraviolet–iodide induced photolysis via hydrogen peroxide formation

《环境科学与工程前沿(英文)》 2022年 第16卷 第5期 doi: 10.1007/s11783-021-1489-0

摘要:

• UV/VUV/I induces substantial H2O2 and IO3 formation, but UV/I does not.

关键词: Vacuum ultraviolet     Hydrogen peroxide     Iodate     Hydroxyl radical     Redox transition    

Effect of calcium lactate on compressive strength and self-healing of cracks in microbial concrete

Kunamineni VIJAY, Meena MURMU

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 515-525 doi: 10.1007/s11709-018-0494-2

摘要: This paper presents the effect on compressive strength and self-healing capability of bacterial concrete with the addition of calcium lactate. Compared to normal concrete, bacterial concrete possesses higher durability and engineering concrete properties. The production of calcium carbonate in bacterial concrete is limited to the calcium content in cement. Hence calcium lactate is externally added to be an additional source of calcium in the concrete. The influence of this addition on compressive strength, self-healing capability of cracks is highlighted in this study. The bacterium used in the study is and was added to both spore powder form and culture form to the concrete. spore powder of 2 million cfu/g concentration with 0.5% cement was mixed to concrete. Calcium lactates with concentrations of 0.5%, 1.0%, 1.5%, 2.0%, and 2.5% of cement, was added to the concrete mixes to test the effect on properties of concrete. In other samples, cultured with a concentration of 1×10 cells/mL was mixed with concrete, to study the effect of bacteria in the cultured form on the properties of concrete. Cubes of 100 mm×100 mm×100 mm were used for the study. These cubes were tested after a curing period of 7, 14 and 28 d. A maximum of 12% increase in compressive strength was observed with the addition of 0.5% of calcium lactate in concrete. Scanning electron microscope and energy dispersive X-ray spectroscopy examination showed the formation of ettringite in pores; calcium silicate hydrates and calcite which made the concrete denser. A statistical technique was applied to analyze the experimental data of the compressive strengths of cementations materials. Response surface methodology was adopted for optimizing the experimental data. The regression equation was yielded by the application of response surface methodology relating response variables to input parameters. This method aids in predicting the experimental results accurately with an acceptable range of error. Findings of this investigation indicated the influence of added calcium lactate in bio-concrete which is quite impressive for improving the compressive strength and self-healing properties of concrete.

关键词: calcium lactate     bacillus subtilis     compressive strength     self-healing of cracks    

Chemical mapping of cement pastes by using confocal Raman spectroscopy

Fengjuan LIU,Zhihui SUN

《结构与土木工程前沿(英文)》 2016年 第10卷 第2期   页码 168-173 doi: 10.1007/s11709-015-0323-9

摘要: In the present study, chemical mapping on the hydration process of cement paste with water-to-cement ( / ) ratio of 0.60 was implemented by Raman spectroscopy (RS). The RS was applied to study the paste from 12 hours after mixing to 28 days. Cement ingredients and hydration products, including calcium silicates (C S and C S), calcium hydroxide (CH), and ettringite, were quantitatively studied. From the research, it is observed that calcium silicates were consumed gradually with the increased hydration age. Calcium hydroxide increased and tended to cluster in the pore vicinity during hydration. Ettringite was found to form on the surface of the unreacted particles, which was shown as a mixed zone of ettringite and calcium silicates in the maps. It is concluded from the study that chemical mapping was an effective method to assist in visualizing particle dispersion and connection on top of the quantitative analysis.

关键词: chemical mapping     Raman spectroscopy     calcium silicates     calcium hydroxide     ettringite    

Appraising the potential of calcium sulfoaluminate cement-based grouts in simulated permafrost environments

《结构与土木工程前沿(英文)》 2023年 第17卷 第5期   页码 722-731 doi: 10.1007/s11709-023-0950-5

摘要: The aim of this study is to appraise the potential of calcium sulfoaluminate (CSA) cement-based grouts in simulated permafrost environments. The hydration and performance of CSA cement-based grouts cured in cold environments (10, 0, and −10 °C) are investigated using a combination of tests, including temperature recording, X-ray diffraction (XRD) tests, thermogravimetric analysis (TGA), and unconfined compressive strength (UCS) tests. The recorded temperature shows a rapid increase in temperature at the early stage in all the samples. Meanwhile, results of the TGA and XRD tests show the generation of a significant quantity of hydration products, which indicates the rapid hydration of CSA cement-based grouts at the early stage at low temperatures. Consequently, the CSA cement-based grouts exhibit remarkably high early strength. The UCS values of the samples cured for 2 h at −10, 0, and 10 °C are 6.5, 12.0, and 12.3 MPa, respectively. The UCS of the grouts cured at −10, 0, and 10 °C increases continuously with age and ultimately reached 14.9, 19.0, and 30.6 MPa at 28 d, respectively. The findings show that the strength of grouts fabricated using CSA cement can develop rapidly in cold environments, thus rendering them promising for permafrost applications.

关键词: permafrost     low temperatures     calcium sulfoaluminate cement-based grouts     hydration reaction     compressive strength    

Evaluation of the technoeconomic feasibility of electrochemical hydrogen peroxide production for decentralized

Yang Li, Yixin Zhang, Guangshen Xia, Juhong Zhan, Gang Yu, Yujue Wang

《环境科学与工程前沿(英文)》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1293-2

摘要: Abstract • Gas diffusion electrode (GDE) is a suitable setup for practical water treatment. • Electrochemical H2O2 production is an economically competitive technology. • High current efficiency of H2O2 production was obtained with GDE at 5–400 mA/cm2. • GDE maintained high stability for H2O2 production for ~1000 h. • Electro-generation of H2O2 enhances ibuprofen removal in an E-peroxone process. This study evaluated the feasibility of electrochemical hydrogen peroxide (H2O2) production with gas diffusion electrode (GDE) for decentralized water treatment. Carbon black-polytetrafluoroethylene GDEs were prepared and tested in a continuous flow electrochemical cell for H2O2 production from oxygen reduction. Results showed that because of the effective oxygen transfer in GDEs, the electrode maintained high apparent current efficiencies (ACEs,>80%) for H2O2 production over a wide current density range of 5–400 mA/cm2, and H2O2 production rates as high as ~202 mg/h/cm2 could be obtained. Long-term stability test showed that the GDE maintained high ACEs (>85%) and low energy consumption (<10 kWh/kg H2O2) for H2O2 production for 42 d (~1000 h). However, the ACEs then decreased to ~70% in the following 4 days because water flooding of GDE pores considerably impeded oxygen transport at the late stage of the trial. Based on an electrode lifetime of 46 days, the overall cost for H2O2 production was estimated to be ~0.88 $/kg H2O2, including an electricity cost of 0.61 $/kg and an electrode capital cost of 0.27 $/kg. With a 9 cm2 GDE and 40 mA/cm2 current density, ~2–4 mg/L of H2O2 could be produced on site for the electro-peroxone treatment of a 1.2 m3/d groundwater flow, which considerably enhanced ibuprofen abatement compared with ozonation alone (~43%–59% vs. 7%). These findings suggest that electrochemical H2O2 production with GDEs holds great promise for the development of compact treatment technologies for decentralized water treatment at a household and community level.

关键词: Advanced oxidation process     Electro-peroxone     Gas diffusion electrode     Hydrogen peroxide     Oxygen reduction    

Effect of potassium carbonate on catalytic synthesis of calcium carbide at moderate temperature

Dejun SHI, Ke QIAO, Zifeng YAN

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 372-375 doi: 10.1007/s11705-010-0570-1

摘要: Calcium carbide was successfully synthesized by carbothermal reduction of lime with coke at 1973 K for 1.5 h. The effect of potassium carbonate as additive on the composition and morphology of the product was investigated using X-ray diffraction and scanning electron microscope. Addition of potassium carbonate increased the yield of calcium carbide. The sample in the presence of potassium carbonate generated acetylene gas of 168.3 L/kg, which was 10% higher than that in the absence of potassium carbonate. This result confirmed the catalytic effect of potassium carbonate on the synthesis of calcium carbide. A possible mechanism of the above effects was that the additive, which was melted at the reduction temperature, dissolved CaO and so promoted the contact between CaO and carbon, which was essential for the solid-solid reaction to form calcium carbide.

关键词: calcium carbide     synthesis     catalysis    

Effects of metal ions on the morphology of calcium sulfate hemihydrate whiskers by hydrothermal method

Tianjie Liu, Hao Fan, Yanxia Xu, Xingfu Song, Jianguo Yu

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 545-553 doi: 10.1007/s11705-017-1665-8

摘要: The effects of Na , Mg , Al and Fe ion concentrations on the crystal morphology of calcium sulfate hemihydrate whiskers formed via a hydrothermal method have been studied. In the presence of Al concentrations higher than 1×10 mol/L the whiskers were significantly shorter and thicker and the presence of Mg and Fe resulted in shorter whiskers. The presence of Na did not affect the morphology of the whiskers. Through elemental analysis, it was determined that Mg and Al were selectively adsorbed on the surfaces of the crystals, whereas Fe underwent a hydrolysis reaction to form a brown precipitate which decreased the ion concentration in the solution. These results indicate that in raw materials used for the industrial preparation of calcium sulfate whiskers, Al and Fe should be removed and the Mg concentration should be less than 8 × 10 mol/L in order to obtain pure whiskers with high aspect ratios.

关键词: metal ions     morphology     calcium sulfate hemihydrate whiskers     hydrothermal method     selective adsorption    

标题 作者 时间 类型 操作

Enhanced carbon tetrachloride degradation by hydroxylamine in ferrous ion activated calcium peroxide

Wenchao Jiang, Ping Tang, Zhen Liu, Huan He, Qian Sui, Shuguang Lyu

期刊论文

Enhanced degradation of trichloroethene by calcium peroxide activated with Fe(III) in the presence of

Xiang ZHANG,Xiaogang GU,Shuguang LU,Zhouwei MIAO,Minhui XU,Xiaori FU,Muhammad DANISH,Mark L. BRUSSEAU,Zhaofu QIU,Qian SUI

期刊论文

Remediation of 2,4-dichlorophenol-contaminated groundwater using nano-sized CaO in a two-dimensional scale tank

期刊论文

The capture of carbon dioxide by transition metal aluminates, calcium aluminate, calcium zirconate, calcium

Ganesh TILEKAR, Kiran SHINDE, Kishor KALE, Reshma RASKAR, Abaji GAIKWAD

期刊论文

On corrosion to stainless steel by calcium chloride with different extender

Lv XU, Yuanyang HU, Liwei WANG, Ruzhu WANG,

期刊论文

Reactive extraction for preparation of hydrogen peroxide under pressure

CHENG Yongxi, LI Hongtao, WANG Li, LÜ Shuxiang

期刊论文

Hydrogen peroxide is correlated with browning in peach fruit stored at low temperature

Zhansheng DING, Shiping TIAN, Xianghong MENG, Yong XU,

期刊论文

Efficient production of hydrogen peroxide in microbial reverse-electrodialysis cells coupled with thermolytic

期刊论文

Toward better understanding vacuum ultraviolet–iodide induced photolysis via hydrogen peroxide formation

期刊论文

Effect of calcium lactate on compressive strength and self-healing of cracks in microbial concrete

Kunamineni VIJAY, Meena MURMU

期刊论文

Chemical mapping of cement pastes by using confocal Raman spectroscopy

Fengjuan LIU,Zhihui SUN

期刊论文

Appraising the potential of calcium sulfoaluminate cement-based grouts in simulated permafrost environments

期刊论文

Evaluation of the technoeconomic feasibility of electrochemical hydrogen peroxide production for decentralized

Yang Li, Yixin Zhang, Guangshen Xia, Juhong Zhan, Gang Yu, Yujue Wang

期刊论文

Effect of potassium carbonate on catalytic synthesis of calcium carbide at moderate temperature

Dejun SHI, Ke QIAO, Zifeng YAN

期刊论文

Effects of metal ions on the morphology of calcium sulfate hemihydrate whiskers by hydrothermal method

Tianjie Liu, Hao Fan, Yanxia Xu, Xingfu Song, Jianguo Yu

期刊论文