JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2024
·
IF 8
Yuxuan Yang,Zhaoping Zhong,Baosheng Jin,Bo Zhang,Haoran Du,Qian Li,Xiang Zheng,Renzhi Qi,Pengkun Ren
Increasing amounts of solid waste and sludge have created many environmental management problems. Pyrolysis can effectively reduce the volume of solid waste and sludge, but there is still the problem of heavy metal contamination, which limits the application of pyrolysis in environmental management. The intercalated-exfoliated modified vermiculite (IEMV) by intercalators of sodium dodecylbenzene sulfonate , hexadecyltrimethylammonium bromide and octadecyltrimethylammonium bromide were used to control the release of Cd, Cr, Cu, Zn and Pb during pyrolysis process of sludge or solid waste. The retention of heavy metals in sludge was generally better than that in solid waste. The IEMV by octadecyltrimethylammonium bromide as the intercalator calcined 800 °C (STAB-800) was the best additive for heavy metal retention, and the retention of Cr, Cu and Zn was significantly better than that of Pb and Cd. Cr, Cu, Zn and Pb were at low risk, while Cd had considerable risk under certain circumstances. New models were proposed to comprehensively evaluate the results of the risk and forms of heavy metals, and the increasing temperature was beneficial in reducing the hazards of heavy metals by the addition of STAB-800. The reaction mechanism of heavy metals with vermiculite was revealed by simulation of reaction sites, Fukui Function and Frontier Molecular Orbital. Thermal activation-intercalated-exfoliated modified vermiculite (T-IEMV) is more reactive and had more active sites for heavy metals. Mg atoms and outermost O atoms are the main atoms for T-IEMV to react with heavy metals. The Cr, Cu and Zn have better adsorption capacity by T-IEMV than Pb and Cd. This study provides a new insight into managing solid waste and sludge and controlling heavy metal environmental pollution .
研究领域:
环境科学
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污染控制
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2014
·
IF 3.552
Hang Long,Pingxiao Wu,Lin Yang,Zhujian Huang,Nengwu Zhu,Zhixian Hu
Ethylamine modified vermiculite (Ethyl-VER) with high specific surface area and excellent pore structure was prepared to remove cesium from aqueous solution. The physic-chemical properties of the pristine and modified vermiculite were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), specific surface area (BET) and scanning electron microscopy/energy disperse spectroscopy (SEM/EDS). The corroding effect of ethylamine increased the specific surface area of vermiculite from 4.35 to 15.59 m 2 g −1 , and the average pore diameter decreased from 6.8 to 5.34 nm. Batch adsorption experiments were conducted as a function of pH, initial Cs + concentration, contact time, coexisting cations (K + , Na + , Ca 2+ ) and low-molecular-weight organic acids (acetic acid, oxalic acid, citric acid) to illustrate the adsorption behavior. The study found that the adsorption capacity of cesium in aqueous solution was improved from 56.92 to 78.17 mg g −1 after modification. The formation of micropores and mesopores and the increased surface area played a critical role in the enhancement of cesium adsorption. Kinetic experiments indicated that the adsorption process can be simulated well with a pseudo-second-order model. The presence of cations or low-molecular-weight organic acids inhibited cesium adsorption in different degrees. On the basis of our results, Ethyl-VER with good surface characteristics and high adsorption capacity is a suitable adsorbent for cesium removal from aqueous solution.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
WASTE MANAGEMENT
·
2024
·
IF 7.1
Yuxuan Yang,Zhaoping Zhong,Baosheng Jin,Bo Zhang,Haoran Du,Qian Li,Xiang Zheng,Renzhi Qi,Pengkun Ren,Zhaoying Li
Pyrolysis is effective in reducing the volume of solid waste and sludge, and produces less pollutants than incineration and landfill, but the process still suffers from heavy metal pollution. Four types of intercalated-exfoliated modified vermiculite (UIV, DIV, TIV and 3IV) were prepared using urea, dimethylsulfoxide, tributyl phosphate and 3-aminopropyltriethoxysilane as intercalators for the control of Cd, Cr, Cu, Pb and Zn in municipal sewage sludge (MSL), paper mill sludge (PML), municipal domestic waste (MWA) and aged refuse (AFE). The larger the interlayer spacing of the vermiculite, the more favorable the retention of heavy metals. 3IV was the most effective additive, with an average retention of more than 75 % of all heavy metals at 450 ℃ for the four raw materials. Cr, Cu, Pb and Zn were all at low potential ecological risk (Pr), while Cd was moderate or considerable Pr, and the addition of 3IV reduced the Pr. Distribution of intercalators between vermiculite interlayers was haphazard, and interlayer spacing results were close to those of the experiment (except for tributyl phosphate). The reactive electrons mainly flowed from the Highest Occupied Molecular Orbital (HOMO) of vermiculite flakes to the Lower Unoccupied Molecular Orbital (LUMO) of heavy metal chlorides. In contrast, the reactive electrons mostly flowed from the HOMO of heavy metal oxides to the LUMO of vermiculite flakes. Heavy metal oxides were more readily adsorbed on vermiculite flakes than heavy metal chlorides, and the adsorption capacity of Cr and Zn was stronger than that of Cd, Pb and Cu.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
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IF 3.99
Shanshan Yang,Zhiyan Huang,Chunquan Li,Wen Li,Lin Yang,Pingxiao Wu
Tetracycline-cadmium combined contaminants have drawn increasing attentions due to their high environmental risk. In this study, vermiculite was modified by dodecyl dimethyl betaine (BS-12) to obtain a kind of organo-vermiculite (BS-VER). After modification, BS-12 was grafted on the surface of vermiculite successfully. Due to the negatively charged head group of BS-12 and improved hydrophobicity of BS-VER, the affinities of BS-VER towards cadmium (Cd 2+ ) and tetracycline (TC) were enhanced. In the single system, the maximum adsorption capacities of Cd 2+ and TC on BS-VER increased from 14.98 to 19.72 mg g −1 and from 16.03–20.95 mg g −1 , respectively. In the binary system, Cd-TC complex was formed and considered to be new adsorption site for Cd 2+ adsorption, resulting in slight enhanced adsorption capacity of BS-VER towards Cd 2+ and TC. Ion exchange, electrostatic attraction, hydrophobic interaction and chelation reaction were the main mechanisms. BS-VER exhibited good advantages in the simultaneous removal of heavy metals and organic contaminants.
研究领域:
环境科学
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污染控制
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产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
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2022
·Vol. 29
·期 5
·1299-1308
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IF 2.523
Gao Jianyang,Zheng Xiaolong,Meng Zilin,Feng Li
The application of layered double hydroxides (LDHs) in remediation was challenged by easy stack and aggregation. To enhance the performance of antibiotics removal capacities, LDHs was supported by vermiculite (VER) through in-situ method (VER–LDH). The structural characterization revealed that LDHs grew on VER surface and formed a three-dimensional structure. Kinetics studies showed that the removal of antibiotics well fitted pseudo-second-order model and intraparticle diffusion model, revealing that adsorption sites are the main factor for adsorption process. Site energy distribution of VER, LDHs and VER–LDH for antibiotics adsorption was estimated based on the equilibrium adsorption data. The energy distribution were determined and indicated that the heterogeneity of the adsorption site. The average site energy of composite material showed a higher value, manifesting a stronger interaction strength between the adsorbent and antibiotics. The excellent removal performance provided a promising strategy in sewage water remediation.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMOSPHERE
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2022
·
IF 8.943
Tao Shen,Tong Han,Qing Zhao,Fan Ding,Shanshan Mao,Manglai Gao
To pursue the adsorptivity of versatile vermiculite (Na-Vt)-based adsorbent targeted at emerging pharmaceuticals (mefenamic acid and ibuprofen, corresponding to MEA and IBP, respectively), a quinoline-based gemini surfactant (DHQU) with multi-functional groups is applied as modifier on Na-Vt. Enhanced hydrophobicity , enlarged interlayer space and decreased surface area of DHQU-Vt are obtained, whose modifier availability (the mole ratio of modifier intercalated to added) reaches up to 84.18% as characterized by FT-IR, XRD , TG-DTG, EA and BET analysis. Efficient adsorption of MEA/IBP (123.71/240.69 mg/g) is achieved under an extremely low DHQU dosage (0.2 CEC lower than the usual saturated dosage of organo-Vts), with all the processes fitting satisfactorily with pseudo-second order and Freundlich isotherm models accompanied by an exothermic nature. Acid pickling testifies a stable and reliable reusability process of DHQU-Vt even after 3 cycles. Multiple interactions (i.e., partition process, XH-π interaction, π-π interaction, π-π stacking and electrostatic interaction) are revealed and compared from not only characterization results, but also simulation of frontier orbital analysis, the adsorption configuration and bonding analysis: (i) The greater molecular flexibility of the adsorbate, the greater intra particle diffusion effect. (ii) π-π stacking between isolated aromatic rings is stronger than that between parallelly connected aromatic rings. (iii) The strength of multiple active sites provided by quinoline (CH-π, NH-π and π-π interactions) are comparable but weaker than electrostatic interaction/intra particle diffusion.
研究领域:
环境科学
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材料科学
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药学
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DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 5
·1407-1416
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IF 3.186
Hong Liang,Yang Jing,Li Yongzheng,Gao Xin,Song Wuling,Zhang Hongxi
Lignocellulosic biofuels are the most promising sustainable fuels for supplementing shrinking fossil resources. In this work, acid-modified vermiculite (AVM)-supported Pd–Ni bimetallic catalyst (Pd–Ni/AVM) was investigated for the hydrodeoxygenation of bio-oil and its model compounds to assess its reactivity. Pd–Ni/AVM was found to efficiently hydrodeoxygenate the investigated model compound (phenol). The phenol conversion reached 94% at 0.5% of Ni loading and temperatures beyond 513 K. Using these parameters, the phenolic hydroxyl group was removed, and the C = C bonds were saturated. This catalyst was also efficient in the hydrodeoxygenation of bio-oil. H 2 -TPR experiments elucidated the synergistic effects between the active component and the carrier, which were considered the main reason for the catalytic activity. Strong influences of the Ni loading and temperature on the hydrogenation of phenol were also observed when the Pd loading was fixed at 1 wt%. Graphic Abstract
研究领域:
能源化学
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催化材料科学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
Yang Xiang,Manglai Gao,Fan Ding,Tao Shen
Imidazolium-based gemini surfactants were attracted extensive attention in recent years with varied benefits such as good biodegradability , low irritant and little toxicity. In this paper, a series of imidazolium-based gemini surfactants with a four-methylene spacer and long hydrophobic chains ([C n -4-C n im]Br 2 , n = 12, 14, 16) were fabricated for modification of vermiculite. The primary characterization of organo-vermiculites (OVts) like Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TG-DTG), scanning electron microscope (SEM), wettability and Elemental Analysis were carried out. The resultant OVts were used to remove dimethyl phthalate (DMP) from aqueous solution, particularly C 14 -4-C 14 im-Vt showed the most promising adsorbability (274.4 mg g −1 ) which is efficient comparing with other adsorbents. The adsorption processes turned out to follow the pseudo-second-order and Langmuir isotherm. Furthermore, the wettabilities of OVts followed the order: C 14 -4-C 14 im-Vt > C 12 -4-C 12 im-Vt > C 16 -4-C 16 im-Vt, which appeared in a positive correlation with the adsorption capacities. Draw a conclusion the sorption occurred primarily via hydrophobic interaction and π–π interaction between OVts and DMP. C 14 -4-C 14 im-Vt could be favorably reproduced by ethanol at least for five cycles. It provides some new thoughts for the possibility of design and synthesis of OVts as high-efficiency adsorbents.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）