Journal of Environmental Sciences
·
2016
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IF 2.208
Wenyu Wang,Shuang Zhao,Qinyan Yue,Baoyu Gao,Wen Song,Lijuan Feng
The objective of this study was to investigate the effect of different Al species and chitosan (CS) dosages on coagulation performance, floc characteristics (floc sizes, strength and regrowth ability and fractal dimension) and membrane resistance in a coagulation–ultrafiltration hybrid process. Results showed that different Al species combined with humic acid in diverse ways. Al a had better removal efficiency, as determined by UV 254 and dissolved organic carbon , which could be further improved by the addition of CS. In addition, the optimal dosage of different Al species was determined to be 4.0 mg/L with the CS concentration of 1.0 mg/L, by orthogonal coagulation experiments. Combining Al a /Al b /Al c with CS resulted in larger flocs, higher recovery, and higher fractal dimension values corresponding to denser flocs; in particular, the floc size at the steady state stage was four times larger than that obtained with Al species coagulants alone. The results of ultrafiltration experiments indicated that the external fouling percentage was significantly higher than that of internal fouling, at around 85% and 15%, respectively. In addition, the total membrane resistance was significantly decreased due to CS addition.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Wenyu Wang,Ruihua Li,Fan Bu,Yue Gao,Baoyu Gao,Qinyan Yue,Min Yang,Yi Li
The pH conditions affected the binding sites and complexation ability of Al species and humic acid (HA), resulting in the difference of coagulation and membrane fouling mechanism. It is important to explore the dynamic process of coagulation for the mechanisms of Al species and HA. In this study, three Al species (Al a /Al b /Al c ) were used in coagulation process to compare the pollution degree of ultrafiltration (UF). Then, the removal efficiency of Al a for DOC was better than that of Al b and Al c , that is, the removal performance of suspended and dissolved organic matter was better for Al a . Through the analysis of coagulation dynamic process and membrane resistances, the flocs formed were smaller size and grow slowly to the equilibrium stage at pH 4, which was easy to cause membrane fouling by concentration polarization. With the pH increasing to a neutral condition, the flocs had a large size and loose structure, and then the porous cake layer was easy to be removed by physical cleaning, leading to the membrane fouling mainly due to pore plugging. Under alkaline conditions, flocs with small size and dense structure were mainly formed by sweeping, which resulted in the cake layer as the main cause of membrane fouling. This study is helpful to optimize the process of HA removal by coagulation-UF, and provides technical support for the coagulation and membrane mechanism of Al species and HA under different pH conditions.
研究领域:
环境科学
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水处理工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
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IF 4.058
Lijuan Feng,Wenyu Wang,Ruiqi Feng,Shuang Zhao,Hongyu Dong,Shenglei Sun,Baoyu Gao,Qinyan Yue
Three species of aluminum coagulants mainly consist of mononuclear Al species (Al a ), medium polymeric species (Al b ) and colloidal species (Al c ) were prepared, separated and purified by organic solvent precipitation method. The effect of different Al species on coagulation performance and membrane fouling were investigated through the coagulation–ultrafiltration hybrid process. The influence of flocs characteristics were also studied to build the relation model between Al species coagulation and membrane fouling mechanisms. The results showed different Al species combined with humic acid (HA) in diverse ways feature distinct floc properties and membrane fouling. Al a coagulant had better UV 254 and dissolved organic carbon (DOC) removal efficiency. Furthermore, Al a and Al c were beneficial to form larger flocs with lower strength and looser structure, whereas Al b was prone to form small flocs with higher strength and compact structure. Ultrafiltration experiments indicated that Al b is the most effective Al species to alleviate membrane fouling.
研究领域:
环境工程
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Wenyu Wang,Qinyan Yue,Kangying Guo,Fan Bu,Xue Shen,Baoyu Gao
The membrane fouling is a challenge for the application of ultrafiltration , one of which the cake layer is the main influencing factor. However, the pros and cons of cake layer generated in the coagulation-ultrafiltration (C-UF) process needs to be explored. This study was carried out to investigate that the effect of a cake layer on the membrane fouling behavior with three Al species coagulants for different effluents. The results indicated that the fouling mechanisms of cake layer under different effluents conditions were diverse due to the particle characteristics. The Al hydrolysis that accompanied by the interaction between Al species coagulants and the –OH/-COOH functional groups of humic acid were conducted, and the effluents of Al a presented lighter membrane fouling. Meanwhile, the components mainly trapped by the membrane were soluble microbial products, protein, polypeptides and amino acid-like materials during C-UF process, because of the decrease in the proportion of fluorescence response. For the less/compact cake layer (system 2), the average of the external and internal membrane resistances were about 25 × 10 10 m −1 and 21 × 10 10 m −1 , respectively, which caused severe membrane fouling. It was concluded that the poriferous/loose cake layer could effectively alleviate membrane fouling by re-adsorbing some organic matters.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2019
·
IF 3.556
Xuejun Xiong,Hui Xu,Beiping Zhang,Xiaohui Wu,Hongyan Sun,Dongsheng Wang,Zhengyang Wang
Membrane filtration combined with pre-coagulation has advantages in advanced wastewater treatment . As a model of a microbial polysaccharide , research on the effect of sodium alginate (SA) on alum hydrolysis has been rare; therefore, it is necessary to gain insight into the interface interaction between SA molecules and Al species, and the role SA plays during floc formation. In this study, the interaction mechanism between SA and Al species has been investigated, by evaluating the effect of SA on floc characteristics and membrane fouling during coagulation–ultrafiltration with different Al species coagulants (AlCl 3 and preformed Al 13 ). Al 2p X-ray photoelectron spectroscopy (XPS) confirmed that the complexation of ligands and Al species strongly affects the reaction pathways for Al hydrolysis and the final nature of the flocs, as Al 13 can be decomposed into octahedral precipitates when SA is added. The presence of SA can affect floc properties, which have important impacts on the characteristics of the cake layer and membrane fouling. Due to the bridging ability of SA, the floc strength increased by about 50% using Al a , which was much better than preformed Al 13 , with a percentage increase of only about 6%. Moreover, the recovery factor of HA-flocs was decreased from 96% to 43% with SA addition of 0.5 mg/L. It was concluded that SA can affect the characteristics of the cake layer and membrane fouling through participating in the formation of primary flocs and altering the Al hydrolysis pathway.
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Qian Zheng,Ziwei Wang,Zhouyang Tian,Lin Cai,Chengfeng Jiang,Lili Deng,Dazhong Yang,Zhenhua Wei
This study introduces a novel and green solid-phase activization technology, which could significantly enhance the chemical reactivity of Si and Al species within kaolinite for zeolite synthesis. Based on this technology, a cost-free kaolinite-rich soil is successfully transformed into A-type zeolite (LTA), a famous and highly productive commercial zeolite. Specifically, solid-phase activization only comprises a green solid-phase ageing step at room temperature and a straightforward heating step at 100°C, showing a progressive activization characteristic. Firstly, the aluminosilicates are fully encapsulated and eroded by the deliquescent NaOH colloids during solid-phase ageing process, occurring preliminary depolymerization. Then upon heating operation, the depolymerization strength of aluminosilicates would be dramatically enhanced, transforming most original Q 3 Si and Al VI species within the soil into Q 0 , Q 1 Si, and Al IV species that are highly desired for zeolite synthesis. Finally, through conventional hydrothermal reaction, the activizated soils could be seamlessly converted into LTA. Compared to the current activization technologies, solid-phase activization exerts superior advantages in terms of activization efficacy, NaOH consumption, energy expenditure, and equipment requirements. Overall, this work shows a novel activization approach for greener aluminosilicate depolymerization and cost-effective LTA synthesis. More remarkably, it significantly broadens the diversity and source options of Si and Al raw materials for zeolite preparation, profoundly enhancing the application potential of silica-alumina minerals within soil and fostering a vast horizon for industries reliant on activizated Si and Al species.
研究领域:
材料科学
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化学工程
·
矿物学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Luo Wu,Rui Zhang,Yaning Zhang,Haiyan Liu,Zhichang Liu,Chunming Xu,Xianghai Meng
Aluminum species in AlCl3–arene and AlCl3–CuCl–arene solutions (including benzene, toluene, o-xylene, m-xylene, p-xylene, and mesitylene) were investigated using 27Al NMR and infrared (IR) spectroscopy. The AlCl3·arene and Al2Cl6·arene complexes were demonstrated experimentally. AlCl3 could not coordinate with benzene and toluene at a low temperature (40 °C) but could form complexes at a high temperature (80 °C). AlCl3 could coordinate with xylene and mesitylene to form Al2Cl6·arene complexes at both low and high temperatures (40 and 80 °C). As for AlCl3–CuCl–arene solutions with a molar ratio of 1:1:2, two signals were observed in 27Al NMR spectra. The signal at around 101 ppm was assigned to CuAlCl4·2arene complexes, and the other signal at around 96 ppm belonged to AlCl3·arene complexes. The characteristic peaks of AlCl3–CuCl–arene solutions in IR spectra moved toward the low field due to the strong π-back-bonding. The CuAlCl4·2arene complexes would convert to CuAl2Cl7·2arene complexes with a further increase in AlCl3 content when the molar ratio of AlCl3/CuCl exceeded 1. The synthesis mechanism of AlCl3–CuCl–arene solutions was analyzed by in situ Fourier transform IR (FTIR) spectroscopy. Three reaction pathways originating from different aluminum species were proposed.
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2021
·
IF 3.498
Tao Li,Zhichao Tao,Ling Zhang,Yong Yang
To achieve facile cost-effective synthesis of acidity-enhanced amorphous silica-alumina (ASA), a water-based sol-gel process is developed. Effectively, this method not only enhances acid sites density, but also lowers the cost by using aluminum nitrate nonahydrate instead of expensive organic aluminum precursor. The resulting material has a uniform mesopore distribution (~3.8 nm) and a large surface area (455 m 2 /g), with very few micropores. And the Brønsted-site density (200 °C) is 1.5 times higher than that of commercialized ASA Siral 70, which is ascribed to the abundant four- and five-coordinated aluminum species. The effectiveness of this as-synthesized ASA has been demonstrated for n -hexadecane hydroisomerization, affording a multi-branched isomer yield of 43.1%. In addition, good performance can be expected in other bulky-molecule-involved cracking and alkylation processes.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Wenyu Wang,Qinyan Yue,Ruihua Li,Fan Bu,Xue Shen,Baoyu Gao
This study investigated membrane fouling in a coagulation/ultrafiltration (C-UF) process by comparing the floc properties and humic acid (HA) removal efficiency of three hydrous Al(III) species (Al a , Al b , and Al c ). The results indicated that the coagulation and membrane mechanisms were different for all three Al species because of the differences in floc properties. The HA removal efficiency increased with increasing Al dosage until an equilibrium was reached at the optimal dosage of 6 mg L −1 . In addition, membrane fouling gradually decreased as the Al dosages increased. Regardless of coagulant type, the OH and COOH functional groups of HA reacted with the Al species. Both external and internal membrane fouling were strongly dependent on the porosity of the cake layer and on the size distribution of the floc particulates, respectively. The pore area of the cake layer formed by the Al a -coagulated effluent was large because of the strong charge neutralization. Moreover, Al a generated large and loose flocs with a porous cake layer that mitigated external fouling. However, the internal fouling with the Al c coagulant was significant because the concentration of residual aggregates in the membrane pores was high.
研究领域:
环境科学
·
水处理工程
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DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2020
·
IF 4.748
Da Zou,Lijun Jin,Mei Zhong,Haoquan Hu,Fengyun Ma
A serials of modified kaolinites were prepared by calcination and further acid treatment and characterized by in-situ XRD, N 2 adsorption, NH 3 -TPD, Py-IR and 27 Al MAS-NMR. And their catalytic performance in pyrolysis of methanol/benzyl phenyl ether (MeOH-BPE), a model compound of low-rank coal, were investigated at 400 °C in a fixed-bed reactor to explore the correlation between the structure of modified samples and their catalytic performances. The results show that calcination temperature above 500 °C causes the collapse of kaolinite structure. Further acid leaching facilitates the formation of micropores and mesopores. The calcination of kaolinite leads to the transformation of six-coordinate Al atoms (Al VI ) into four and five coordinate species (Al IV and Al V ), while the subsequent acid treatment increases the contents of Al IV and Al VI and removes Al V . Total acid sites exhibit a first increase and then decrease tendency with the raising calcination temperature. In the presence of the modified kaolinites, BPE conversion significantly enhances and reaches the highest value of 91.41% over K-A-700 prepared by calcination at 700 °C of kaolinite and further acid leaching. Besides, the maximum content of phenol and toluene is also achieved due to the highest acid sites and Al IV content of K-A-700, which favors the generation of ·H, thus resulting in an obvious inhibition of bibenzyl formation but a significant increase of 2-benzylphenol. In-situ pyrolysis by time-of-flight mass spectrometry suggests that the cleavage of C al -O bond of BPE to form phenol radicals and benzyl radicals is the primary way, while insufficient ·H results in the formation of dominant product of 2-benzylphenol.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Zhenyu Wu,Zengxi Li,Chunshan Li
The bare amorphous Al 2 O 3 -AlPO 4 and Cs/Al 2 O 3 -AlPO 4 catalysts were developed for the aldol condensation of methyl acetate with formaldehyde to methyl acrylate. The structure and property of catalyst were characterized by XRD, XPS, BET, Pyridine-IR, FT-IR, 27 Al-MASNMR, NH 3 -/CO 2 -TPD and SEM. The correlation between structural features and acid-base properties was established, and the loading effect of the cesium species was investigated. Due to cooperative catalytic effects between the penta-coordinated Al and Al 2 O 3 , the weak-II acid and medium acid site densities and the product selectivity were improved. While the basic site densities of these catalysts were almost in proportion to the conversion of methyl acetate. The loaded Cs could form new basic sites and change the distribution of acid sites which further enhance the catalytic performance. As a result, the 10Cs/8AlP was proved to be an optimal catalyst with the yield and selectivity of 21.2% and 85% for methyl acrylate respectively. During the reaction, a deactivation behavior was observed on 10Cs/8AlP catalyst due to the carbon deposition, however, it could be regenerated by thermal treatment in the air atmosphere at 400 °C.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 15
·4837-4850
·
IF 6.177
Haoyi Lin,Jiaxing Zhang,Qingxu Duan,Kaixuan Yang,Weiping Liao,Shixue Qi,Hongying Lü,Zhiguo Zhu
Plentiful heteroatom-containing zeolites as versatile redox catalysts have been successfully post-synthesized via the top-down methodology, where the starting aluminosilicate zeolites are normally expected to be highly dealuminated to maximize the amounts of silanol nests and occasionally to evade the detrimental effect of framework Al ions on the catalytic performance. Herein, our proposed dealumination-controlled strategy for the synthesis of hierarchical Ti–Y zeolite breaks through this concept. Framework-substituted Ti and tri-coordinated Al species were afforded from the interaction of Ti ions with dealumination-derived silanol nests and from the process of acid treatment, respectively. Structure–function relationships revealed that Lewis acid sites were the catalytically active centres of Ti–Y zeolite in oxidative desulfurization with hydrogen peroxide as the oxidant, which came from the cooperative effect of dual active sites containing framework-substituted Ti and tri-coordinated Al species. The amounts of Lewis acid sites demonstrated a volcanic-type trend as the acid-treatment time increases. The reusability, regeneration ability, deactivation mechanism were also systematically investigated in oxidative desulfurization. Thus the Ti–Y zeolite catalyst was also effective for Baeyer–Villiger oxidation of 2-adamantanone. This work discloses the effectiveness of preparing an efficient Ti–Y zeolite catalyst with cooperative dual active sites via a dealumination-controlled strategy, which bears potential application for constructing other heteroatom-containing FAU-type zeolites with Lewis acid property.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）