ACS Omega
·
2024
·
IF 3.7
Xianqi Hu,Zhuang Ma
In this study, we introduce a novel series of gemini surfactants with amide groups (HDAB, HDAHD, and HDAPX) and use these surfactants to decorate sodium vermiculite (Na-Vt) for the adsorption of Ibuprofen (IBP) from wastewater. Exceptional IBP uptake on organo-vermiculites (organo-Vts) is obtained, with maximum adsorption capacities reaching 249.87, 342.21, and 460.15 mg/g for HDAB-Vt, HDAHD-Vt, and HDAPX-Vt (C0 = 500 mg/L, modifier dosage = 0.2 CEC), respectively. The adsorption of IBP is well fitted by pseudo-second-order, intraparticle diffusion, and Freundlich isotherm models, verifying chemical adsorption processes with multilayer arrangement of IBP in organo-Vts. Thermodynamically, the removal of IBP on HDAHD-Vt is exothermic, while the endothermic nature aptly describes the adsorption process of HDAB-Vt and HDAPX-Vt. Moreover, organo-Vts can be stably regenerated in three cycles. Outstanding adsorption performance of organo-Vts is attributed to synergistic effects of the partition process and functional interaction, which are influenced by the steric hindrance and chain configuration of the modifier. A combined evaluation of adsorption tests and fitting calculations is employed to reveal the adsorption mechanism: (i) the incorporation of amides into the alkyl chain significantly enhances the utilization of the interlayer space in organo-Vts. (ii) Smaller steric hindrance and higher rigidity of the modifier spacer contribute to improved adsorption performance. The findings in this study rekindle interest in Vt-based adsorbents, which demonstrate comparable potential to other emerging adsorbents that are yet to be fully explored.
研究领域:
环境科学
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材料科学
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化学工程
·
水处理
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DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
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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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
JOURNAL OF APPLIED POLYMER SCIENCE
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2012
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IF 1.289
Panfang Lu,Min Zhang,Yong Liu,Jiuling Li,Ming Xin
The thermoplastic starch–vermiculite (VER) composite films were prepared by solution-casting technique in this study. First, the VER was used as the filler reinforcement for thermoplastic starch to enhance its properties. The modification of VER and the structure of films were investigated and characterized by X-ray diffraction and scanning electron microscope technology. Moreover, the Fourier transform infrared spectra confirmed that the VER particles formed strong hydrogen bond interactions with starch matrix. According to TGA, differential scanning calorimetry study, and water absorption testing, the starch–VER composite films exhibited better improvement properties than did the starch matrix. It provides information on the use of VER to reinforce the properties of starch-based materials. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
研究领域:
材料科学
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生物材料
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高分子化学
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DOI
高影响因子
APPLIED CLAY SCIENCE
·
2018
·
IF 3.641
Liya Chen,Pingxiao Wu,Meiqing Chen,Xiaolin Lai,Zubair Ahmed,Nengwu Zhu,Zhi Dang,Yingzhi Bi,Tongyun Liu
The chitosan/vermiculite biocomposite (CTS-VMT) was synthesized successfully with epichlorohydrin (ECH) cross-linking agent and used to remove cadmium and lead from the aqueous solution. CTS-VMT was characterized by FTIR , SEM, BET, TG-DTG, zeta potential and XPS . The effects of critical parameters including solution pH, contact time, initial heavy-metal concentration and adsorbent regeneration were investigated. Besides, adsorption mechanisms were also researched. The results indicated that chitosan molecule cannot intercalate into the interlayer space but cross link on the external surface of VMT. The maximum adsorption capacities for Cd(II) and Pb(II) were 58.48 mg g − 1 and 166.67 mg g − 1 at pH 4, respectively. The adsorption process fitted well the pseudo-second-order model and the adsorption isotherms could be correctly simulated by the Langmuir isotherm model. The zeta potential analyses put forward that electrostatic attraction existed in the adsorption process between the metal cations and CTS-VMT. However, the principal mechanism for adsorption on CTS-VMT was chelation according to the kinetic study and XPS analyses. Moreover, the desorption experiments revealed the prepared adsorbent tended to be regenerated by using HCl and the removal rations for four cycles were all > 90%. Therefore, the synthesized CTS-VMT in this study has the potential to be utilized as an eco-friendly adsorbent for removing Cd(II) and Pb(II).
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
SEPARATION SCIENCE AND TECHNOLOGY
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2022
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IF 2.799
Yaxun Sun,Xin Li,Tingting Wang,Yaxiong Ji,Yihang Yue,Yong Li,Shifeng Wang
In this study, a multi-hydroxyl-containing gemini surfactant 1,4-bis(hexadecyldimethylammonio)-2,3-dihydroxylbutane dibromide (BHHB) is firstly introduced to modify vermiculite (Na-Vt) for 2-naphthol adsorption. Successful functionalization is verified from the enhanced hydrophobicity, increased organic carbon content, enlarged interlayer spacing and decreased surface area of BHHB-Vt over Na-Vt, constructing favorable structural microenvironments for 2-naphthol retention. Effective adsorptivity and excellent reusability are obtained from the comparison of BHHB-Vt (198.16 mg/g) over Na-Vt (43.26 mg/g C0 = 300 mg/L, V = 30 mL, m = 0.03 g, t = 3 h). Partition process, hydrogen bond, OH-π interaction and electrostatic attraction are responsible for the adsorption, where OH-π interaction is stronger than hydrogen bond. The agreement of pseudo-second order and Langmuir models indicate a chemical adsorption feature on homogeneous surface. Notably, hydrogen groups connected at different carbon atoms exhibit less steric hindrance and wider molecule orbitals, providing stronger interactions between the adsorbent and targeted organic pollutant.
研究领域:
环境科学
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材料化学
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产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2024
·
IF 5.3
Tiancheng Gu,Junjie Xu,Fengdan Zhu,Zhengmao Ding,Yunjun Luo
Sustainable, clean, seawater-river interface osmotic energy shows great potential in replacing traditional fossil fuel sources. Two-dimensional (2D) nanofluidic channels, known for their high throughput, high integration density, and excellent scalability, render practical applications feasible for osmotic energy harvesting. However, 2D nanofluidic channels face challenges such as high internal resistance and high costs, which keep the ultimate goal of large-scale osmotic energy harvesting distant. Herein, a novel method to regulate ion transport resistance by constructing different hydrophilic asymmetric nanofluidic channels using bilayer membrane of vermiculite and MXene is proposed. Vermiculite nanosheets are prepared via polymer-assisted exfoliation method utilizing polyethyl-phosphate glycol ester. After simple stirring and maturation process, the exfoliation concentration can reach 20 phr within 8 h, which is 20 times higher than the previously reported maximum. The internal resistance of the bilayer membrane decreased from 24.1 kΩ to 15.0 kΩ as the direction of ions transport changes. Oxygen plasma assistance enabled the bilayer membrane to reach a maximum power density of 4.66 W m −2 . The high-efficiency preparation method of vermiculite nanosheets and the emphasis on membrane surface properties offer new insights into practical osmotic energy harvesting.
研究领域:
材料科学
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能源工程
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产品关联
DOI
高影响因子
MOLECULES
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2022
·Vol. 27
·期 10
·3149
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IF 4.927
Xingtao Chen,Dongshen Tong,Zhi Fang,Zhenpeng Gao,Weihua Yu
Vermiculite is a natural mineral. In this study, vermiculite and acid-activated vermiculite was used as a solid acid catalyst for the hydrolysis of cellulose in water. The catalysts were characterized by XRD, FT-IR, and BET. The effects of time, temperature, mass ratio and water amount on the reaction were investigated in the batch reactor. The results showed that the highest total reducing sugars (TRS) yield of 40.1% could be obtained on the vermiculite activated by 35 (wt)% H2SO4with the mass ratio of catalyst to cellulose of 0.18 and water to cellulose of 16 at 478 K for 3.5 h. The acid-activated vermiculite was a stable catalyst through calcination at 628 K and the yield of TRS decreased to 36.2% after three times reuse. The results showed that the crystal structure of vermiculite was destroyed and the surface -OH groups increased after the acid treatment. However, the synergistic effect of a strongly electrostatic polarization and Brönsted acid was responsible for the efficient conversion of cellulose. The mechanism of cellulose hydrolysis on the acid-activated vermiculite was suggested. This work provides a promising strategy to design an efficient solid catalyst for the cellulose hydrolysis, and expands the use of vermiculite in a new field.
研究领域:
化学工程
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可再生资源
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2015
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IF 2.711
Lytuong Tran,Pingxiao Wu,Yajie Zhu,Shuai Liu,Nengwu Zhu
A novel approach to prepare adsorbents for Hg(II) uptake from aqueous media based on the grafting of dimercaprol (BAL), containing thiol and hydroxyl groups, onto the natural montmorillonite and vermiculite was investigated concerning the evaluation of the adsorption capacity. The kinetic study showed that the adsorption process abided by pseudo-second-order model. The adsorption behavior of Hg(II) onto the obtained samples fitted well with Langmuir isotherm model, exhibiting an enhanced maximum adsorption capacity of 8.57 and 3.21 mg g −1 for BAL-Vm and BAL-Mt, respectively. The feasibility of Hg(II) uptake onto the the samples was studied thermodynamically and the calculated coefficients such as Δ H , Δ S and Δ G indicated a physical and spontaneous process. The pH values and coexisting cations had a great influence on Hg(II) removal, confirming the optimal pH value of 4.0–5.0 and the negative correlation between the ionic strength and the adsorption capacity of Hg(II). In general, BAL-Vm possessed a higher efficiency of Hg(II) uptake than BAL-Mt, contrary to that of the pristine clays. The pristine and functionalized materials were investigated by XRD, FTIR, BET, SEM and zeta potential analysis to gain in-depth insight into the structure and surface morphology. The results showed that BAL was successful grafted on montmorillonite and vermiculite surface, providing plentiful adsorption sites as chelating ligands. The mechanisms of Hg(II) adsorption on these samples could be further explained as ion exchange and electrostatic attraction for Vm and Mt, and formation of complexes for BAL-Vm and BAL-Mt.
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
APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Haibin Yang,Junzhen Guo,Liang Chu,Zhi Huang,Zhaohui Liu,Liyan Wang,Zhaokun Wang,Mu Yang,Ge Wang
Utilizing natural, abundant, and eco-friendly materials to facilitate the industrial application of nano-sized MOF particles is of utmost importance, since these nanoparticles possess high activity but difficult to recovery. Herein, benefiting from the negatively charged vermiculite , dispersed nano-sized Fe-MOF particles were successfully in-situ grown on the surface of vermiculite nanosheets (VNs) via a simple solvothermal method. The construction of the composites improved the exposure of organic dye to active sites, resulting in a remarkable performance of Fe-MOF@VNs-4 towards photo-Fenton degradation of RhB , with a k value of 0.096 min −1 and an activity of 0.581 mmol g −1 h −1 , significantly higher than that of pure VNs and Fe-MOF, surpassing most reported MOF composite catalysts. The excellent adsorption ability of Fe-MOF@VNs, along with the presence of divalent iron in vermiculite, greatly enhanced catalytic performance. Mechanistic investigations revealed that VNs facilitate the separation of photoinduced carriers excited from Fe-MOF, indicating a synergy effect between Fe-MOF and VNs. Overall, this work provides a simple and effective strategy to design large-scale and commercially available catalysts for water treatment , and also offers a promising alternative for the industrial application of nano-sized MOF particles.
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
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
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Chun Wang,Bai-Hang Zhao,Bao-Yu Zhang,Yi-Hao Zhu,Ye Li
The presence of antibiotics in wastewater threatens the human living environment. Activated peroxymonosulfate (PMS) method is often used for catalytic degradation of antibiotics. However, how to reduce catalyst cost and ensure efficient degradation of antibiotics at the same time is a sticky issue for the activated PMS method. Two-dimensional vermiculite flakes (2D-VMT) is cost-effective and can be used as catalyst carriers for PMS activation. Hence, we exfoliated 2D-VMT from natural vermiculite and prepared NiCo 2 O 4 loaded 2D-VMT (NiCo 2 O 4 /2D-VMT) catalyst. Levofloxacin (LVX), as a normal antibiotic , was used to evaluate the catalytic capacity of NiCo 2 O 4 /2D-VMT in PMS systems. Also, LVX degradation mechanism through NiCo 2 O 4 /2D-VMT activated PMS were explored here. XRD , EDS, TEM, and HRTEM analysis all demonstrated NiCo 2 O 4 nanoparticles were successfully anchored on 2D-VMT. NiCo 2 O 4 /2D-VMT had a high specific surface area and abundant active sites. The NiCo 2 O 4 /2D-VMT/PMS system, with a 15% mass ratio of NiCo 2 O 4 to 2D-VMT (15%-CN/2D-VMT), achieved LVX removal efficiency of 87% and LVX removal rate of 0.034 min −1 . 1 O 2 and SO 4 · - were the major ROS for LVX degradation. The reversible redox cycle between Co(III)/Co(II) and Ni(III)/Ni(II) played a crucial role in activating PMS to generate ROS for LVX degradation process. Also, based on intermediates identification by LC-MS, possible degradation pathways of LVX were proposed and their ecotoxicological evolution was assessed by using the ECOSAR software. 15%-CN/2D-VMT may be a worth recommended loaded catalyst for antibiotics removal in environmental remediation, owing to its high reusability and excellent renewability.
研究领域:
环境科学
·
催化材料
·
污染治理
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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）