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Effect of alkyl nitrite decomposition on catalytic performance of CO coupling reaction over supported

Zhenhua LI, Weihan WANG, Dongxue YIN, Jing LV, Xinbin MA

《化学科学与工程前沿（英文）》 2012年 第6卷 第4期   页码 410-414 doi: 10.1007/s11705-012-1213-5

摘要： The syntheses of dimethyl oxalate (DMO) and diethyl oxalate (DEO) by CO coupling reaction in gaseous phase were investigated in a fixed bed reactor over Pd-Fe/Al O catalyst. The catalytic performance was characterized by CO conversion, space-time yield (STY) and selectivity of DMO (or DEO). The results showed that over Pd-Fe/Al O catalyst, the STY of DMO was higher than that of DEO under the same reaction conditions. The optimum reaction temperatures for synthesizing DMO and DEO were 403 K and 393 K, respectively, at the molar ratio 1 ∶ 1 of alkyl nitrite to CO. The difference in synthesizing DMO and DEO on the same catalyst was attributed to the decomposition performances of methyl nitrite (MN) and ethyl nitrite (EN), as density functional theory (DFT) calculation showed that EN decomposed more easily than MN.

关键词： palladium     CO coupling     dialkyl oxalate     alkyl nitrite     decomposition    

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Kinetics of UV curable alkyl 3-mercaptopropionate-vinyl silizane

SONG Jiale, CHEN Lixin, WANG Yazhou, CHEN Weiwei, WANG Rumin

《化学科学与工程前沿（英文）》 2008年 第2卷 第4期   页码 390-395 doi: 10.1007/s11705-008-0080-6

摘要： Photopolymerization of vinyl-containing liquid silizane preceramic monomers copolymerized with thiol monomers, based on a step-growth radical polymerization mechanism, is a novel, rapid, inexpensive and simple technique for producing preceramic structures from liquid precursors. The kinetics of alkyl 3-mercptopropionate-vinyl silizane under UV irradiation is investigated by using real-time Fourier transform infrared (FT-IR) and photo-differential scanning calorimetry (photo-DSC). The experimental results show preliminarily that: (1) about 80% conversion of vinyl group has been achieved in the presence of a low concentration photoinitiator under UV irradiation; (2) by increasing the functionalities of the thiol group, the peak rate of copolymerization increases and the final conversion of the vinyl group decreases; (3) the copolymerization is primarily a bimolecular radical termination process; (4) the copolymerization is first-order, i.e., its rate is proportional to the vinyl group concentration and independent of the concentration of thiol group.

关键词： step-growth     irradiation     bimolecular     preceramic     concentration photoinitiator    

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Surface hydrophobicity: effect of alkyl chain length and network homogeneity

Wenqian Chen, Vikram Karde, Thomas N. H. Cheng, Siti S. Ramli, Jerry Y. Y. Heng

《化学科学与工程前沿（英文）》 2021年 第15卷 第1期   页码 90-98 doi: 10.1007/s11705-020-2003-0

摘要： Understanding the nature of hydrophobicity has fundamental importance in environmental applications. Using spherical silica nanoparticles (diameter= 369€±€7 nm) as the model material, the current study investigates the relationship between the alkyl chain network and hydrophobicity. Two alkyl silanes with different chain length (triethoxymethylsilane (C1) vs. trimethoxy(octyl)silane (C8)) were utilised separately for the functionalisation of the nanoparticles. Water contact angle and inverse gas chromatography results show that the alkyl chain length is essential for controlling hydrophobicity, as the octyl-functionalised nanoparticles were highly hydrophobic (water contact angle= 150.6°€±€6.6°), whereas the methyl-functionalised nanoparticles were hydrophilic (i.e., water contact angle= 0°, similar to the pristine nanoparticles). The homogeneity of the octyl-chain network also has a significant effect on hydrophobicity, as the water contact angle was reduced significantly from 148.4°€±€3.5° to 30.5°€±€1.0° with a methyl-/octyl-silane mixture (ratio= 160:40 µL·g nanoparticles).

关键词： hydrophobicity     surface energy     wettability     alkyl chain network     silica nanoparticle    

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Lignin-based polymer with high phenolic hydroxyl group content prepared by the alkyl chain bridging method

《化学科学与工程前沿（英文）》 2023年 第17卷 第8期   页码 1075-1084 doi: 10.1007/s11705-022-2272-x

摘要： Inspired by the importance of the phenolic group to the electron transporting property of hole transport materials, phenolic hydroxyl groups were introduced in lignosulfonate (LS) via the alkyl chain bridging method to prepare phenolated-lignosulfonate (PLS). The results showed that the phenolic group was boosted from 0.81 mmol∙g–1 of LS to 1.19 mmol∙g–1 of PLS. The electrochemical property results showed two oxidation peaks in the cyclic voltammogram (CV) curve of PLS, and the oxidation potential of the PLS-modified electrode decreased by 0.5 eV compared with that of LS. This result indicates that PLS is more easily oxidized than LS. Based on the excellent electron transporting property of PLS, PLS was applied as a dopant in poly(3,4-ethylenedioxythiophene) (PEDOT, called PEDOT:PLSs). PLS showed excellent dispersion properties for PEDOT. Moreover, the transmittance measurement results showed that the transmittance of PEDOT:PLSs exceeded 85% in the range of 300–800 nm. The CV results showed that the energy levels of PEDOT:PLSs could be flexibly adjusted by PLS amounts. The results indicate that the phenolic hydroxyl group of lignin can be easily boosted by the alkyl chain bridging method, and phenolated lignin-based polymers may have promising potential as dopants of PEDOT to produce hole transporting materials for different organic photovoltaic devices.

关键词： lignosulfonate     phenolic group     PEDOT:PLS     hole extract layer     energy level    

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Denitrification and phosphorus uptake by DPAOs using nitrite as an electron acceptor by step-feed strategies

Bin MA, Shuying WANG, Guibing ZHU, Shijian GE, Junmin WANG, Nanqi Ren, Yongzhen PENG

《环境科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 267-272 doi: 10.1007/s11783-012-0439-2

摘要： Denitrifying phosphorus accumulating organisms (DPAOs) using nitrite as an electron acceptor can reduce more energy. However, nitrite has been reported to have an inhibition on denitrifying phosphorus removal. In this study, the step-feed strategy was proposed to achieve low nitrite concentration, which can avoid or relieve nitrite inhibition. The results showed that denitrification rate, phosphorus uptake rate and the ratio of the phosphorus uptaken to nitrite denitrified (anoxic P/N ratio) increased when the nitrite concentration was 15 mg·L after step-feeding nitrite. The maximum denitrification rate and phosphorus uptake rate was 12.73 mg and 18.75 mg , respectively. These rates were higher than that using nitrate (15 mg·L ) as an electron acceptor. The maximum anoxic P/N ratio was 1.55 mg . When the nitrite concentration increased from 15 to 20 mg after addition of nitrite, the anoxic phosphorus uptake was inhibited by 64.85%, and the denitrification by DPAOs was inhibited by 61.25%. Denitrification rate by DPAOs decreased gradually when nitrite (about 20 mg·L ) was added in the step-feed SBR. These results indicated that the step-feed strategy can be used to achieve denitrifying phosphorus removal using nitrite as an electron acceptor, and nitrite concentration should be maintained at low level (<15 mg·L in this study).

关键词： denitrifying phosphate accumulating organisms (DPAOs)     denitrification     phosphorus uptake     nitrite     step-feed     enhanced biological phosphorus removal    

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of activated sludge aggregates using microelectrodes in completely autotrophic nitrogen removal over nitrite

Yongtao LV,Xuan CHEN,Lei WANG,Kai JU,Xiaoqiang CHEN,Rui MIAO,Xudong WANG

《环境科学与工程前沿（英文）》 2016年 第10卷 第2期   页码 390-398 doi: 10.1007/s11783-015-0818-6

摘要： Microsensor measurements and fluorescence in situ hybridization (FISH) analysis were combined to investigate the microbial populations and activities in a laboratory-scale sequencing batch reactor (SBR) for completely autotrophic nitrogen removal over nitrite (CANON). Fed with synthetic wastewater rich in ammonia, the SBR removed 82.5±5.4% of influent nitrogen and a maximum nitrogen-removal rate of 0.52 kgN·m ·d was achieved. The FISH analysis revealed that aerobic ammonium-oxidizing bacteria (AerAOB) and anaerobic ammonium-oxidizing bacteria (AnAOB) dominated the community. To quantify the microbial activities inside the sludge aggregates, microprofiles were measured using pH, dissolved oxygen (DO), , and microelectrodes. In the outer layer of sludge aggregates (0–700 μm), nitrite-oxidizing bacteria (NOB) showed high activity with 4.1 μmol·cm ·h of maximum nitrate production rate under the condition of DO concentration higher than 3.3 mg·L . Maximum AerAOB activity was detected in the middle layer (depths around 1700 μm) where DO concentration was 1.1 mg·L . In the inner layer (2200–3500 μm), where DO concentration was below 0.9 mg·L , AnAOB activity was detected. We thus showed that information obtained from microscopic views can be helpful in optimizing the SBR performance.

关键词： microelectrodes     CANON     aerobic ammonium-oxidizing bacteria     anaerobic ammonium-oxidizing bacteria     nitrite-oxidizing bacteria    

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Effects of nitrite on phosphate uptake in anaerobic-oxic process

LI Jie, XIONG Biyong, ZHANG Shude, YANG Hong, ZHANG Jie

《环境科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 39-42 doi: 10.1007/s11783-007-0007-3

摘要： An anaerobic-oxic (A/O) biological phosphorus removal reactor was operated to study the effect of nitrite on phosphate uptake. The phosphorus uptake profile was determined under different operating conditions. The results indicated that in addition to oxygen and nitrate (DPB, nitrate denitrifying phosphorus removal), to some extent, nitrite could also serve as an electron acceptor to achieve nitrite denitrifying phosphorus removal (DPB). The quantity and rate of phosphorus uptake of DPB, however, were evidently lower than that of DPB The experiment results revealed that nitrite would bring toxic action to phosphate-accumulating organisms (PAOs) when NO-N"e93.7 mg/L. The nitrite existing in the anoxic reactor made no difference to the quantity and rate of denitrifying phosphorus removal, but it could reduce the consumption of nitrate. Moreover, the data showed that the aerobic phosphate uptake of DPB was lower than that of anaerobic phosphorus-released sludge in a traditional A/O process. However, there was not much difference between these two kinds of sludge in terms of the total phosphorus uptake quantity and the effluent quality.

关键词： effluent     PAOs     experiment     phosphate-accumulating     phosphorus removal    

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method for efficient control of hydrogen sulfide and methane in gravity sewers: Combination of NaOH and Nitrite

《环境科学与工程前沿（英文）》 2022年 第16卷 第6期 doi: 10.1007/s11783-021-1509-0

摘要：

• The combination of NaOH and nitrite was used to control harmful gas in sewers.

关键词： Sewer corrosion     Sulfide control     Combination treatment     NaOH     Nitrite    

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A simple, azulene-based colorimetric probe for the detection of nitrite in water

Lloyd C. Murfin, Carlos M. López-Alled, Adam C. Sedgwick, Jannis Wenk, Tony D. James, Simon E. Lewis

《化学科学与工程前沿（英文）》 2020年 第14卷 第1期   页码 90-96 doi: 10.1007/s11705-019-1790-7

摘要： We describe the synthesis and evaluation of an azulene-based chemodosimeter for nitrite. The probe was found to undergo two distinct color changes upon introduction aqueous nitrite ion. A near-instant formation of a grey color provides a qualitative indication of the presence of nitrite, followed by the formation of a deep-yellow/orange color, the endpoint from which quantitative data can be derived. The azulene probe exhibits 1:1 stoichiometry of reaction with nitrite in water, and is selective for nitrite over other anions. The azulene probe was applied to determine nitrite content in cured meat, and compared with the British Standard testing procedure (Griess test). The value obtained from the azulene-based probe agreed closely with the standard test. Our procedure only requires the preparation of one standard solution, instead of the three required for the standard Griess test.

关键词： azulene     nitrite     diazoquinone    

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Experimental study of nitrite accumulation in pre-denitrification biological nitrogen removal process

WU Xuelei, CHEN Lunqiang, PENG Yongzhen, WANG Pu, WANG Yayi

《环境科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 236-240 doi: 10.1007/s11783-008-0008-x

摘要： The effect of dissolved oxygen (DO) concentration on nitrite accumulation was investigated in a pilot-scale pre-denitrification process at room temperature for 100 days. In the first 10 days, due to the instability of the system, the DO concentration fluctuated between 1.0 and 2.0 mg/L. In the next 14 days, the DO concentration was kept at 0.5 mg/L and nitrite accumulation occurred, with the average nitrite accumulation rate at 91%. From the 25th day, the DO concentration was increased to 2.0 mg/L to destroy the nitrite accumulation, but nitrite accumulation rate was still as high as 90%. From the 38th day the nitrite accumulation rate decreased to 15%–30% linearly. From the 50th day, DO concentration was decreased to 0.5 mg/L to resume nitrite accumulation. Until the 83rd day the nitrite accumulation rate began to increase to 80%. Dissolved oxygen was the main cause of nitrite accumulation, taking into account other factors such as pH, free ammonia concentration, temperature, and sludge retention time. Because of the different affinity for oxygen between nitrite oxidizing bacteria and ammonia oxidizing bacteria when DO concentration was kept at 0.5 mg/L, nitrite accumulation occurred.
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Performance of completely autotrophic nitrogen removal over nitrite process under different aeration

GUO Jinsong, YANG Guohong, FANG Fang, QIN Yu

《环境科学与工程前沿（英文）》 2008年 第2卷 第4期   页码 439-445 doi: 10.1007/s11783-008-0046-4

摘要： In this study, three sequential batch biofilm reactors (SBBRs) were operated for 155 days to evaluate the performance of completely autotrophic nitrogen removal over nitrite (CANON) process under different aeration modes and dissolved oxygen (DO). Synthetic wastewater with 160-mg NH-N/L was fed into the reactors. In the continuously-aerated reactor, the efficiency of the ammonium nitrogen conversion and total nitrogen (TN) removal reached 80% and 70%, respectively, with DO between 0.8–1.0 mg/L. Whereas in the intermittently-aerated reactor, at the aeration/non-aeration ratio of 1.0, ammonium was always under the detection limit and 86% of TN was removed with DO between 2.0–2.5 mg/L during the aeration time. Results show that CANON could be achieved in both continuous and intermittent aeration pattern. However, to achieve the same nitrogen removal efficiency, the DO needed in the intermittently-aerated sequential batch biofilm reactor (SBBR) during the aeration period was higher than that in the continuously-aerated SBBR. In addition, the DO in the CANON system should be adjusted to the aeration mode, and low DO was not a prerequisite to CANON process.

关键词： Synthetic wastewater     process     Whereas     biofilm     detection    

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The impact of ultrasonic treatment on activity of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria

Siqi Li, Min Zheng, Shuang Wu, Yu Xue, Yanchen Liu, Chengwen Wang, Xia Huang

《环境科学与工程前沿（英文）》 2019年 第13卷 第6期 doi: 10.1007/s11783-019-1166-8

摘要： • Conditions for ultrasonic treatment to achieve partial nitritation are optimized. • Ultrasound reduces metabolic activity and releases intracellular metabolites. • Mechanical shearing is essential to inhibit nitrite oxidation. The ultrasonic treatment of sludge has been considered as an effective method to facilitate the partial nitritation of municipal sewage. This study aims to reveal the effects of ultrasound on ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). The impact factors including ultrasonic irradiation time and intensity, sludge concentration, thermal effect and released free radicals were studied. The maximized difference between the changes in AOB and NOB activities were obtained with 10 g mixed liquor suspended solids (MLSS)/L, using 0.9 kJ/mL ultrasonic energy density and 12 h interval time. The increased ultrasonic intensity destroyed the floc structure of activated sludge, increased the microbial death, and decreased the cellular ATP level. Further, the mechanism exploration indicated that the mechanical shearing could be a critical factor in achieving the nitritation with inhibitory effect on nitrite oxidation.

关键词： Ultrasonic treatment     Optimal control     Nitrifying bacteria     Mechanism analysis    

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Unveiling the interaction mechanisms of key functional microorganisms in the partial denitrification-anammox process induced by COD

《环境科学与工程前沿（英文）》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1703-3

摘要：

● The availability of PD-anammox was investigated with higher NO3––N concentration.

关键词： PD-anammox process     Nitrite accumulation     COD     Microbial interaction    

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Gas phase ethylene polymerization over SiO

Liuzhong LI, Aiyou HAO, Ruihua CHENG, Boping LIU

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 89-95 doi: 10.1007/s11705-010-0558-x

摘要： Although an important industrial catalyst for producing high density polyethylene, the SiO -supported organosilyl chromate UCC S-2 catalyst has not been fully investigated compared with the SiO -supported oxo chromium Phillips catalyst. In this work, gas phase ethylene polymerization by S-2 catalysts (Cat-1, Cat-2, and Cat-3) was carried out in a high-speed stirred-autoclave reactor. The effects of temperature, time, and pressure on kinetics, activity, and product properties were studied. All kinetics were typical built-up types with slow decay. Compared to the simple physical mixtures of Cat-1 and Cat-2, Cat-3 showed higher activity and its product had a broader molecular weight distribution, indicating new active species induced during blending of Cat-1 and Cat-2 in -hexane. The innovation by a simple catalyst technology created a new application to meet market demands.

关键词： UCC S-2 catalyst     Al-alkyl co-catalyst     gas-phase ethylene polymerization     high density polyethylene    

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Catalytic reduction for water treatment

Maocong Hu, Yin Liu, Zhenhua Yao, Liping Ma, Xianqin Wang

《环境科学与工程前沿（英文）》 2018年 第12卷 第1期 doi: 10.1007/s11783-017-0972-0

摘要： Treating water contaminants via heterogeneously catalyzed reduction reaction is a subject of growing interest due to its good activity and superior selectivity compared to conventional technology, yielding products that are non-toxic or substantially less toxic. This article reviews the application of catalytic reduction as a progressive approach to treat different types of contaminants in water, which covers hydrodehalogenation for wastewater treatment and hydrogenation of nitrate/nitrite for groundwater remediation. For hydrodehalogenation, an overview of the existing treatment technologies is provided with an assessment of the advantages of catalytic reduction over the conventional methodologies. Catalyst design for feasible catalytic reactions is considered with a critical analysis of the pertinent literature. For hydrogenation, hydrogenation of nitrate/nitrite contaminants in water is mainly focused. Several important nitrate reduction catalysts are discussed relating to their preparation method and catalytic performance. In addition, novel approach of catalytic reduction using in situ synthesized H evolved from water splitting reaction is illustrated. Finally, the challenges and perspective for the extensive application of catalytic reduction technology in water treatment are discussed. This review provides key information to our community to apply catalytic reduction approach for water treatment.

关键词： Halogenated compounds     Nitrate/nitrite contaminants     Hydrodechloriantion     Hydrogenation     Wastewater treatment     Groundwater remediation    

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标题 作者 时间 类型 操作

Effect of alkyl nitrite decomposition on catalytic performance of CO coupling reaction over supported

Zhenhua LI, Weihan WANG, Dongxue YIN, Jing LV, Xinbin MA

期刊论文

Kinetics of UV curable alkyl 3-mercaptopropionate-vinyl silizane

SONG Jiale, CHEN Lixin, WANG Yazhou, CHEN Weiwei, WANG Rumin

期刊论文

Surface hydrophobicity: effect of alkyl chain length and network homogeneity

Wenqian Chen, Vikram Karde, Thomas N. H. Cheng, Siti S. Ramli, Jerry Y. Y. Heng

期刊论文

Lignin-based polymer with high phenolic hydroxyl group content prepared by the alkyl chain bridging method

期刊论文

Denitrification and phosphorus uptake by DPAOs using nitrite as an electron acceptor by step-feed strategies

Bin MA, Shuying WANG, Guibing ZHU, Shijian GE, Junmin WANG, Nanqi Ren, Yongzhen PENG

期刊论文

of activated sludge aggregates using microelectrodes in completely autotrophic nitrogen removal over nitrite

Yongtao LV,Xuan CHEN,Lei WANG,Kai JU,Xiaoqiang CHEN,Rui MIAO,Xudong WANG

期刊论文

Effects of nitrite on phosphate uptake in anaerobic-oxic process

LI Jie, XIONG Biyong, ZHANG Shude, YANG Hong, ZHANG Jie

期刊论文

method for efficient control of hydrogen sulfide and methane in gravity sewers: Combination of NaOH and Nitrite

期刊论文

A simple, azulene-based colorimetric probe for the detection of nitrite in water

Lloyd C. Murfin, Carlos M. López-Alled, Adam C. Sedgwick, Jannis Wenk, Tony D. James, Simon E. Lewis

期刊论文

Experimental study of nitrite accumulation in pre-denitrification biological nitrogen removal process

WU Xuelei, CHEN Lunqiang, PENG Yongzhen, WANG Pu, WANG Yayi

期刊论文

Performance of completely autotrophic nitrogen removal over nitrite process under different aeration

GUO Jinsong, YANG Guohong, FANG Fang, QIN Yu

期刊论文

The impact of ultrasonic treatment on activity of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria

Siqi Li, Min Zheng, Shuang Wu, Yu Xue, Yanchen Liu, Chengwen Wang, Xia Huang

期刊论文

Unveiling the interaction mechanisms of key functional microorganisms in the partial denitrification-anammox process induced by COD

期刊论文

Gas phase ethylene polymerization over SiO

Liuzhong LI, Aiyou HAO, Ruihua CHENG, Boping LIU

期刊论文

Catalytic reduction for water treatment

Maocong Hu, Yin Liu, Zhenhua Yao, Liping Ma, Xianqin Wang

期刊论文