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Adsorptive behaviors of humic acid onto freshly prepared hydrous manganese dioxides

LIU Ruiping, LI Guibai, YANG Yanling, HE Wenjie, HAN Hongda

《环境科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 240-245 doi: 10.1007/s11783-007-0041-1

摘要: This study focused on the adsorptive behaviors of humic acid onto freshly prepared hydrous MnO(s) (δMnO), and investigated the feasibility of employing δMnO for humic acid removal from drinking water. Effects of such parameters as molecular mass of humic acid, kinds of divalent cations on adsorptive behaviors and possible mechanisms involved were investigated. This study indicated that humic acid with higher molecular mass exhibited more tendency of adsorbing onto &MnO than that with lower molecular mass. Ca facilitated more humic acid adsorption than Mg; UV-Vis spectra analysis indicated higher capabilities of Ca coordinating with acidic functional groups of humic acid than that of Mg. Additionally, ζ potential characterization indicated that Ca showed higher potential of increasing ζ potential of &MnO than Mg. Ca of 1.0 mmol/L increased ζ potential of δMnO

关键词: Mg     molecular     functional     UV-Vis spectra     prepared hydrous    

Atomic force microscopy study on the microtopography of natural organic matter and newly formed hydrous

GUO Jin, MA Jun, SHI Xuehua

《环境科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 251-256 doi: 10.1007/s11783-007-0043-z

摘要: To understand the water purification mechanism of potassium permanganate as a coagulation-aid during the preoxidation process, the microtopography of its reductive products, the newly formed hydrous manganese dioxide and the aged hydrous manganese dioxide, was investigated. The morphology of natural organic matter (NOM) adsorbed by the newly formed hydrous manganese dioxide was also compared with that of NOM alone. By using the tapping mode atomic force microscopy (AFM), the observation results show that the newly formed hydrous manganese dioxide possess a perforated sheet (with a thickness of 0 1.75 nm) as well as some spherical particle structures compared with the hydrous manganese dioxide with 2 h aging time, which demonstrated that the newly formed hydrous manganese dioxide had a large surface area and adsorption capacity. When 1 mmol/L newly formed hydrous manganese dioxide was added, the microtopography of NOM molecules shifted from a loosely dispersed pancake shape (with adsorption height of 5 8.5 nm) to a densely dispersed and uniform spherical structure. These results provide a valid proof that it is the perfect adsorption capability of the newly formed hydrous manganese dioxide that might result in the coagulation aid effect of potassium permanganate preoxidation.

关键词: spherical     microtopography     potassium permanganate     uniform spherical     morphology    

Influence of coagulation bath on morphology of cellulose membranes prepared by NMMO method

LU Yangcheng, WU Yingxin

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 204-208 doi: 10.1007/s11705-008-0027-y

摘要: To control the morphology of cellulose membranes used for separation, they were prepared by the NMMO method using water, methanol, ethanol and their binary solution as coagulation baths. Morphologies of the surface and cross section of dry membranes were observed. The pore structure parameters of wet membranes were determined. By comparison, the process and mechanism of pore formation in dry membranes were suggested, and the relativity of cellulose crystal size to average pore diameter in wet membranes and their influences were discussed. The results show that the morphology of dry membranes is clearly varied with coagulation baths, while the porosity of wet membranes is almost constant. Porous structures can appear in the compact region of dry membranes due to swelling from water. These pores have a virtual effect on the average pore diameter of wet membranes. By changing the composition of coagulation baths, the microstructure of cellulose membranes in a dry or wet environment can be adjusted separately.

关键词: comparison     NMMO     constant     diameter     process    

Smart contract applications in the built environment: How prepared are Nigerian construction stakeholders

《工程管理前沿(英文)》 doi: 10.1007/s42524-023-0275-z

摘要: Studies have demonstrated that advanced technology, such as smart contract applications, can enhance both pre- and post-contract administration within the built environment sector. Smart contract technology, exemplifying blockchain technologies, has the potential to improve transparency, trust, and the security of data transactions within this sector. However, there is a dearth of academic literature concerning smart contract applications within the construction industries of developing countries, with a specific focus on Nigeria. Consequently, this study seeks to explore the relevance of smart contract technology and address the challenges impeding its adoption, offering strategies to mitigate the obstacles faced by smart contract applications. To investigate the stakeholders, this research conducted 14 virtual interview sessions to achieve data saturation. The interviewees encompassed project management practitioners, senior management personnel from construction companies, experts in construction dispute resolution, professionals in construction software, and representatives from government construction agencies. The data obtained from these interviews underwent thorough analysis employing a thematic approach. The study duly recognizes the significance of smart contract applications within the sector. Among the 12 identified barriers, issues such as identity theft and data leakage, communication and synchronization challenges, high computational expenses, lack of driving impetus, excessive electricity consumption, intricate implementation processes, absence of a universally applicable legal framework, and the lack of a localized legal framework were recurrent impediments affecting the adoption of smart contract applications within the sector. The study also delves into comprehensive measures to mitigate these barriers. In conclusion, this study critically evaluates the relevance of smart contract applications within the built environment, with a specific focus on promoting their usage. It may serve as a pioneering effort, especially within the context of Nigeria.

关键词: built environment industry     digitalization     Nigeria     smart contract     technological revolution    

Reactive adsorption desulfurization over a Ni/ZnO adsorbent prepared by homogeneous precipitation

Aihua KONG, Yanyu WEI, Yonghong LI

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 170-176 doi: 10.1007/s11705-013-1322-9

摘要: A high-performance Ni/ZnO adsorbent was prepared by homogeneous precipitation using urea hydrolysis and characterized by N adsorption-desorption, X-ray diffraction (XRD), and scanning electron microscope (SEM). The adsorbent was applied to the deep desulfurization of gasoline and showed a high breakthrough sulfur capacity and a remarkably high volume hourly space velocity. The effects of coexisting olefins in gasoline as well as adsorptive conditions on the adsorptive performance were examined. It was found that olefins in gasoline had a slightly inhibiting effect on the desulfurization performance of the adsorbent. The optimum conditions were 673 K, 1.0 Mpa with a volume hourly space velocity of 60 h . Under the optimum conditions, ultralow sulfur gasoline could be produced and the breakthrough sulfur capacity of the adsorbent was 360 mg-s/g-sorb for the model gasoline.

关键词: nickel     reactive adsorption     desulfurization     thiophene    

weight and concentration of carboxymethyl cellulose on morphology of hydroxyapatite nanoparticles as prepared

Ruiqiang LIU,Rattan LAL

《环境科学与工程前沿(英文)》 2015年 第9卷 第5期   页码 804-812 doi: 10.1007/s11783-015-0785-y

摘要: Nano-sized apatite particles (nAP) synthesized with carboxymethyl cellulose (CMC) have shown great application potentials in in situ heavy metal remediation. However, differences in CMC’s properties effects on the size of nAP produced are not well understood. In this paper, two types of CMC, with respective molecular weights (MW) of ~120000 and ~240000 Dalton or respective polymerization degrees of 500 (CMC-500) and 1050 (CMC-1050), were studied in a concentration range of 0.05%–0.5% (w/w) for nAP synthesis. Morphology of the particles was characterized with transmission electron microscopy (TEM). Results showed that 0.05% CMC-500 solution gave an average particle size of 148.7±134.9 nm, 0.25% CMC-500 solution produced particles of 21.8±20.4 nm, and, 0.5% CMC-500 solution contained particles of 15.8±7.7 nm. In comparison, 0.05% CMC-1050 solution produced nanoparticles of 6.8±3.2 nm, 0.25% CMC-1050 produced smaller nAP of 4.3±3.2 nm, and 0.5% CMC-1050 synthesized the smallest nanoparticles in this study, with an average diameter of 3.0±2.1 nm. Chemical composition of the products was identified with X-ray diffraction (XRD) as pure hydroxyapatite. Interactions between nAP and CMC were discussed with help of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic data. This study showed that CMC at higher concentration as well as higher MW facilitated to produce finer nanoparticles, showing that nAP size could be manipulated by selecting appropriate CMC MW and/or applying appropriate CMC concentration.

关键词: nanotechnology     nanoparticles     apatite     carboxymethyl cellulose (CMC)     particle size    

Erratum to: One-step ball milling-prepared nano Fe

Xingguo Guo, Qiuying Wang, Ting Xu, Kajia Wei, Mengxi Yin, Peng Liang, Xia Huang, Xiaoyuan Zhang

《环境科学与工程前沿(英文)》 2020年 第14卷 第4期 doi: 10.1007/s11783-020-1258-5

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    

Formic acid dehydrogenation reaction on high-performance PdAu alloy nanoparticles prepared by the eco-friendly

《能源前沿(英文)》   页码 751-762 doi: 10.1007/s11708-023-0895-3

摘要: Dehydrogenation of formic acid (FA) is considered to be an effective solution for efficient storage and transport of hydrogen. For decades, highly effective catalysts for this purpose have been widely investigated, but numerous challenges remain. Herein, the PdxAu1−x (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1) alloys over the whole composition range were successfully prepared and used to catalyze FA hydrogen production efficiently near room temperature. Small PdAu nanoparticles (5–10 nm) were well-dispersed and supported on the activated carbon to form PdAu solid solution alloys via the eco-friendly slow synthesis methodology. The physicochemical properties of the PdAu alloys were comprehensively studied by utilizing various measurement methods, such as X-ray diffraction (XRD), N2 adsorption–desorption, high angle annular dark field-scanning transmission electron microscope (HAADF-STEM), X-ray photoelectrons spectroscopy (XPS). Notably, owing to the strong metal-support interaction (SMSI) and electron transfer between active metal Au and Pd, the Pd0.5Au0.5 obtained exhibits a turnover frequency (TOF) value of up to 1648 h−1 (313 K, nPd+Au/nFA = 0.01, nHCOOH/nHCOONa = 1:3) with a high activity, selectivity, and reusability in the FA dehydrogenation.

关键词: FA dehydrogenation     face-centred cubic structures     PdAu solid solution alloy nanoparticles     slow synthesis methodology     SMSI effect    

Effect of PEG additives on properties and morphologies of polyetherimide membranes prepared by phase

Jian CHEN, Jiding LI, Xia ZHAN, Xiaolong HAN, Cuixian CHEN,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 300-306 doi: 10.1007/s11705-009-0280-8

摘要: This study investigated the effect of poly(ethylene glycol) (PEG) additive as a pore-former on the structure formation of membranes and their permeation properties connected with the changes in thermodynamic and kinetic properties in the phase inversion process. The membranes were prepared by using polyetherimide/-methyl-2-pyrrolidone/PEG (PEI/NMP/PEG) casting solution and water coagulant. The resulting membranes, prepared by changing the ratio of PEG to PEI, were characterized by scanning electron microscope (SEM) observations, measurements of water flux and -globin rejection. The thermodynamic and kinetic properties of the membrane-forming system were studied through viscosity. The pore radius distribution curves were especially obtained by differential scanning calorimetry (DSC). Furthermore, the membranes were characterized for pure water flux and rejection of solute and by SEM observation. The filtration results agreed well with the SEM observations. As expected, PEG with a fixed molecular weight (PEG 600) acted as a pore forming agent, and membrane porosity increased as the PEG content of the casting solution increased.

关键词: permeation     ethylene     filtration     PEI/NMP/PEG     membrane    

Characterization and catalytic properties of mesoporous CuO/SBA-16 prepared by different impregnation

DONG Yongli, YUAN Fulong, ZHU Yujun, ZHAO Lina, CAI Zhicheng

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 150-154 doi: 10.1007/s11705-008-0036-x

摘要: CuO/SBA-16 catalysts were prepared by two different routes – the conventional impregnation method and the modified impregnation method with pH adjustment. These catalysts were characterized by X-ray diffraction (XRD), atomic absorption spectrometry (AAS), N physisorption and hydrogen temperature programmed reduction (H-TPR) measurements which reveal that the cubic cage-like () pore structure of the parent SBA-16 molecule sieves was well maintained throughout the synthesis. After introduction of Cu, a different CuO dispersion exists on these catalysts. The CuO/SBA-16 prepared by modified impregnation method has a single highly dispersed CuO which is considered as a highly efficient species for hydroxylation of phenol with HO. CuO/SBA-16 prepared by the conventional impregnation method shows the presence of bulk CuO species which is undesirable for this reaction.

关键词: different     CuO/SBA-16     temperature     physisorption     introduction    

Biogenic palladium prepared by activated sludge microbes for the hexavalent chromium catalytic reduction

Luman Zhou, Chengyang Wu, Yuwei Xie, Siqing Xia

《环境科学与工程前沿(英文)》 2020年 第14卷 第2期 doi: 10.1007/s11783-019-1206-4

摘要: • Pd nanoparticles could be reduced and supported by activated sludge microbes. • The effect of biomass on Pd adsorption by microbes is greater than Pd reduction. • More biomass reduces Pd particle size, which is more dispersed on the cell surface. • When the biomass/Pd add to 6, the catalytic reduction rate of Cr(VI) reaches stable. Palladium, a kind of platinum group metal, owns catalytic capacity for a variety of hydrogenations. In this study, Pd nanoparticles (PdNPs) were generated through enzymatic recovery by microbes of activated sludge at various biomass/Pd, and further used for the Cr(VI) reduction. The results show that biomass had a strong adsorption capacity for Pd(II), which was 17.25 mg Pd/g sludge. The XRD and TEM-EDX results confirmed the existence of PdNPs associated with microbes (bio-Pd). The increase of biomass had little effect on the reduction rate of Pd(II), but it could cause decreasing particle size and shifting location of Pd(0) with the better dispersion degree on the cell surface. In the Cr(VI) reduction experiments, Cr(VI) was first adsorbed on bio-Pd with hydrogen and then reduced using active hydrogen as electron donor. Biomass improved the catalytic activity of PdNPs. When the biomass/Pd (w/w) ratio increased to six or higher, Cr(VI) reduction achieved maximum rate that 50 mg/L of Cr(VI) could be rapidly reduced in one minute.

关键词: Palladium nanoparticles     Activated sludge     Hexavalent chromium    

Solution properties and self-association of multi-blocks like copolymer P(AM/AA) prepared by template

ZHANG Yuxi, WU Feipeng, LI Miaozhen, WANG Erjian

《化学科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 68-71 doi: 10.1007/s11705-007-0014-8

摘要: The association and properties of multi-block like copolymers (TP) of acrylamide (AM) and acrylic acid (AA) prepared by template copolymerization in aqueous solution were studied. The results showed that the copolymers of this type exhibited a significant structure effect compared with that of similar random copolymers (CP) obtained by copolymerization in the absence of template. Decreasing the value of pH or adding Ca ion to the copolymer solution will make phase separation occur. The TEM images demonstrated that the phase separation caused by Ca ion was due to the formation of extensively intermolecular cross-linking. With the increase of the pH value of copolymer solution, the changes of the solution viscosity was similar with that of homopolyacrylic acid, which originally increased and then decreased. But the increase range of template copolymer was higher than that of homopolyacrylic acid. TEM images indicated that at the maximal viscosity the copolymer obtained in the presence of template formed coiled aggregates.

关键词: aqueous solution     homopolyacrylic     copolymer solution     significant structure     presence    

Novel polyethyleneimine/TMC-based nanofiltration membrane prepared on a polydopamine coated substrate

Zhe Yang, Xiaoyu Huang, Jianqiang Wang, Chuyang Y. Tang

《化学科学与工程前沿(英文)》 2018年 第12卷 第2期   页码 273-282 doi: 10.1007/s11705-017-1695-2

摘要: Most commercial NF membranes are negatively charged at the pH range of a typical feed solution. In order to enhance the removal of cations (such as Mg or Ca ), we utilized polyethyleneimine (PEI) and trimesoyl chloride (TMC) to perform interfacial polymerization reaction on a polydopamine coated hydrolyzed polyacrylonitrile substrate to obtain a positively charged nanofiltration membrane. Effects of polydopamine coating time, PEI concentration, TMC reaction time and concentration on the membrane physicochemical properties and separation performance were systematically investigated using scanning electron microscopy, streaming potential and water contact angle measurements. The optimal NF membrane showed high rejection for divalent ions (93.6±2.6% for MgSO , 92.4±1.3% for MgCl , and 90.4±2.1% for Na SO ), accompanied with NaCl rejection of 27.8±2.5% with a permeation flux of 17.2±2.8 L·m ·h at an applied pressure of 8 bar (salt concentrations were all 1000 mg·L ). The synthesized membranes showed promising potentials for the applications of water softening.

关键词: nanofiltration     polyethyleneimine     trimesoyl chloride     polydopamine     positively charged rejection layer    

Synthesis of methanol and ethanol over CuZnAl slurry catalyst prepared by complete liquid-phase technology

Wei HUANG, Linmei YU, Wenhui LI, Zhili MA

《化学科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 472-475 doi: 10.1007/s11705-010-0525-6

摘要: A new method, named the complete liquid-phase technology, has been applied to prepare catalysts for methanol synthesis. Its main innovative thought lies in preparing slurry catalysts directly from raw solution. Activity tests indicate that the CuZnAl slurry catalyst prepared by the new method can efficiently catalyze conversion of syngas to ethanol in a slurry reactor, while CO conversion reaches 35.9% and ethanol selectivity is more than 20%, with a total alcohol selectivity of more than 87%. No deactivation was found during the 192 h reaction .

关键词: methanol     slurry     ethanol     complete liquid-phase technology     CuZnAl catalyst    

标题 作者 时间 类型 操作

Adsorptive behaviors of humic acid onto freshly prepared hydrous manganese dioxides

LIU Ruiping, LI Guibai, YANG Yanling, HE Wenjie, HAN Hongda

期刊论文

Atomic force microscopy study on the microtopography of natural organic matter and newly formed hydrous

GUO Jin, MA Jun, SHI Xuehua

期刊论文

Influence of coagulation bath on morphology of cellulose membranes prepared by NMMO method

LU Yangcheng, WU Yingxin

期刊论文

Smart contract applications in the built environment: How prepared are Nigerian construction stakeholders

期刊论文

Reactive adsorption desulfurization over a Ni/ZnO adsorbent prepared by homogeneous precipitation

Aihua KONG, Yanyu WEI, Yonghong LI

期刊论文

weight and concentration of carboxymethyl cellulose on morphology of hydroxyapatite nanoparticles as prepared

Ruiqiang LIU,Rattan LAL

期刊论文

Erratum to: One-step ball milling-prepared nano Fe

Xingguo Guo, Qiuying Wang, Ting Xu, Kajia Wei, Mengxi Yin, Peng Liang, Xia Huang, Xiaoyuan Zhang

期刊论文

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

期刊论文

Formic acid dehydrogenation reaction on high-performance PdAu alloy nanoparticles prepared by the eco-friendly

期刊论文

Effect of PEG additives on properties and morphologies of polyetherimide membranes prepared by phase

Jian CHEN, Jiding LI, Xia ZHAN, Xiaolong HAN, Cuixian CHEN,

期刊论文

Characterization and catalytic properties of mesoporous CuO/SBA-16 prepared by different impregnation

DONG Yongli, YUAN Fulong, ZHU Yujun, ZHAO Lina, CAI Zhicheng

期刊论文

Biogenic palladium prepared by activated sludge microbes for the hexavalent chromium catalytic reduction

Luman Zhou, Chengyang Wu, Yuwei Xie, Siqing Xia

期刊论文

Solution properties and self-association of multi-blocks like copolymer P(AM/AA) prepared by template

ZHANG Yuxi, WU Feipeng, LI Miaozhen, WANG Erjian

期刊论文

Novel polyethyleneimine/TMC-based nanofiltration membrane prepared on a polydopamine coated substrate

Zhe Yang, Xiaoyu Huang, Jianqiang Wang, Chuyang Y. Tang

期刊论文

Synthesis of methanol and ethanol over CuZnAl slurry catalyst prepared by complete liquid-phase technology

Wei HUANG, Linmei YU, Wenhui LI, Zhili MA

期刊论文