PHYSICA SCRIPTA
·
2025
·Vol. 100
·期 6
·065916
·
IF 2.6
Pouria Pourhosseinhendabad,Parisa Z Firouzabadi
Bentonite clay, nano-bentonite, and nano-clays are used in many industries such as medical, water purification, food processing, and drilling mud. But because impurities in low-grade bentonite occur, its efficiency is limited; therefore, purification and modification are carried out to enhance its quality. Cetyltrimethylammonium bromide (CTAB), cationic modifier, dispersants, and milling are used in this study's improved process for synthesizing nano-bentonite and industrial bentonite purification. CTAB was the preferred choice since it possessed the ability to modify further such parameters as surface charge, hydrophobicity, and cation exchange capacity, thus rendering bentonite more effective for its applications. The removal of impurities was mainly facilitated by the dispersants during sedimentation and centrifugation. The best sample, BMP 2 h, has shown a tremendous reduction in the cristobalite and calcite impurities with an increase in the beidellite phase as confirmed by x-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The process reduced particle size from raw bentonite 121.75 μm to 1.07 μm of BMP 2 h, which enabled improved dispersion. The enhanced purity and changed behavior of nano-bentonite reveal its potential for future industrial use in water treatment, catalysis, and drilling mud. This optimized method offers a cost-effective and efficient path to high-quality nano-bentonite, solving the limitations of current purification methods.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2014
·
IF 0.987
Ruihua Huang,Bo Wang,Bingchao Yang,Dongsheng Zheng,Zengqiang Zhang
An adsorbent was prepared from bentonite modified by hexadecyltrimethylammonium bromide (HDTMAB) and N-2-hydroxypropyl trimethyl ammonium chloride chitosan (HTCC). This adsorbent was named as HDTMAB–HTCC bentonite. It would be used for the simultaneous adsorption of phenol and Cr(VI) from aqueous solution. By the method of single-factor experiment, the optimum preparation conditions of HDTMAB–HTCC bentonite were obtained. For bentonite (5 g), 1.0 g HDTMAB and 0.5 g HTCC were adopted as the modifying reagents. The reaction was carried out for 2 h at 80°C. The removals towards phenol and Cr(VI) enhanced with the increase in the amount of adsorbent dosage. The relatively high removals towards phenol and Cr(VI) occurred at a pH value of 1.5 or so. During the simultaneous adsorption process of phenol and Cr(VI), phenol was adsorbed by the partition from the organic phase formed by HDTMAB, while Cr(VI) was mostly adsorbed by the electrostatic interactions between HTCC and Cr(VI). No direct competition was observed due to different adsorption sites.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2017
·
IF 3.101
Tao Wu,Zhifen Wang,Hai Wang,Zhiqiang Zhang,Luc R. Van Loon
The through-diffusion method was employed to investigate the effect of the salt concentration on the diffusion behaviour of Re(VII) and Se(IV) in compacted bentonite . The accessible porosity , ε acc , of Re(VII) increased from 0.25 to 0.38 with an increase of the ionic strength from 0.1 to 1.0 mol/L. The dependency of the accessible porosity ε acc on the salt concentration could be described approximately by a first-order decay exponential function. The interlayer porosity of GMZ bentonite was 21% of the total porosity at a bulk dry density of 1600 kg/m 3 at 12 °C. The D e values of Re(VII) and Se(IV) increased from 2.6 × 10 − 11 to 6.1 × 10 − 11 m 2 /s and from 1.6 × 10 − 11 to 4.7 × 10 − 11 m 2 /s in GMZ bentonite with an increase of the ionic strength from 0.1 to 1.0 mol/L, respectively. In the case of Se(IV), the adsorption showed a different ionic strength dependency in GMZ bentonite and montmorillonite . The ionic strength has no significant effect on the adsorption (K d = 1.8 × 10 − 4 m 3 /kg) on GMZ bentonite, indicating the formation of inner-sphere surface complexes. In the case of synthetic montmorillonite, the K d values increased with increasing ionic strength. This can be explained by the fact that the electric potential of surface sites becomes less negative with increasing ionic strength resulting in an increase in the adsorption of Se(IV) at a pH above the point of zero salt effect (PZSE). The D e values of both Re(VII) and Se(IV) increased with increasing salt concentration. Both anions are totally excluded from the interlayer space and partially from the diffuse double layer. Ionic strength alters the effective diffusion coefficient of anions by controlling the thickness of the diffuse double layer. Anion diffusion data from the literature (effective and apparent diffusion coefficients) were satisfactorily evaluated by Archie's relation.
研究领域:
环境科学
·
地球化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 142
·期 4
·e56404
·
IF 2.7
Song Li,Lingbo Dong,Jinyi Jia,Licong Jiang,Zhenxiang Xin,Wei Liu,Lin Li
A large amount of smoke will be produced during the combustion of ethylene propylene diene monomer(EPDM), which seriously endangers the environment and personal safety. In this study, K-SEP was obtained by modifying sepiolite with KH550, and two bio-based flame retardant and smoke suppression systems AEGS and PEGS were prepared by combining ammonium polyphosphate intumescent flame retardant system (AEG) and piperazine pyrophosphate intumescent flame retardant system (PEG), respectively. The flame retardant and smoke suppression properties of AEGS and PEGS on EPDM matrix composites were investigated. The experimental results show that the LOI values of EPDM/AEGS3 and EPDM/PEGS3 composites with 3 phr K-SEP are 8.1% and 5.5% higher than those of the blank samples without sepiolite. TSP decreased by 26.3% and 14.3% respectively, which proved that sepiolite has important research value in the field of flame retardant and smoke suppression of polymer materials.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Yaohui Sun,Yanhui Li,Bing Chen,Mingzhen Wang,Yang Zhang,Kewei Chen,Qiuju Du,Yuqi Wang,Xinxin Pi
It can be difficult to remove dark methylene blue (MB) from water effectively. The use of sodium alginate and bentonite (Ben) as the matrix produced a displacement reaction that occurred in cobalt chloride, which allowed Ben to be successfully encapsulated in cobalt alginate (CA). Finally, a vacuum freeze-drying method was used to prepare a low-cost composite of CA/Ben aerogel for adsorbing MB in aqueous solutions. In addition to scanning electron microscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy, the composites were also characterized and analyzed. Different adsorption experiments were conducted in order to determine the effects of dosage, pH, adsorption time, and temperature on the adsorption performance of the adsorbent. According to the results of the experiment, the adsorption capacity of CA/Ben aerogel was 258.92 mg·g–1, and the pseudo-first-order kinetic model and Freundlich isotherm model can fully explain the adsorption process of MB on this aerogel. The composite material reported in this paper is easily recycled, and the removal rate reaches 65% after four times of recycling. Moreover, compared with other adsorbents, the composite material of the invention is highly environmentally friendly and has a simple preparation process. A large-scale application of this technology is the removal of dyes from water on a large scale.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2020
·Vol. 10
·期 1
·1-18
·
IF 3.998
Wang Yanting,Gong Shengying,Li Yazhuo,Li Zhang,Fu Jie
In this study, a novel, sustainable and efficient ceramsite substrate of constructed wetlands (CWs) were prepared for tetracycline (TC) removal by employing bentonite (Ben) and red mud (Rm) as the main materials and pine sawdust (Ps) as the additive. The optimal parameters for Ben/Rm/Ps ceramsite preparation were obtained via orthogonal and one-factor experimental designs, and the optimal parameters were presented as follows: mass ratio of Ben: Rm: Ps = 4:1:0.9, preheating temperature = 240 °C, preheating time = 20 min, calcining temperature = 1150 °C, and calcining time = 14 min. The properties of Ben/Rm/Ps-op ceramsite (obtained at the optimal condition) were first analyzed, including XRD and SEM, and demonstrated a microporous structure with some crystal strength components. Neutral condition and higher temperature were indicated conducive to improve the TC removal efficiency, while coexisting ions (Na + or Ca 2+ ) showed adverse effect for TC adsorption by Ben/Rm/Ps-op. In addition, adsorption kinetics and isotherm could be well described by the second-order kinetics and linear isothermal model, respectively, which suggested chemisorption and multilayer adsorption thickness increased infinitely. The theoretical maximum TC adsorption capacity of Ben/Rm/Ps-op at 20 °C reached up to 2.5602 mg/g. In addition, Ben/Rm/Ps-op could effectively remove TC as the CWs substrate under a dynamic flow condition. Further, Ben/Rm/Ps-op exhibited high reusability capability and stability for TC removal, and the adsorption amount still remained for 2.13 mg/g ( C 0 = 80 mg/L) after three consecutive cycles.
研究领域:
环境科学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NUCLEAR TECHNOLOGY
·
2022
·
IF 1.667
Yanhui Wang,Qiao Jiang,Yexin Yang,Jianfeng Cheng,Chenyang Bao,Yuelong Pan,Yu Liu,Gang Yang,Yangchun Leng,Xianguo Tuo
The alteration of the morphology of bentonite, a key barrier to isolating high-level radioactive waste in deep geological repositories under long-term interaction with groundwater, was studied. Bentonite colloids were prepared from Gaomiaozi bentonite, and its various properties were analyzed by various characterization methods. The effects of various factors on the adsorption of Cs(I) and Co(II) on bentonite colloids were investigated by batch static adsorption experiments. The results showed that the colloids were mainly composed of montmorillonite and were lamellar in shape, with a zeta potential of −enton mV and an average size of approximately 209.10 nm. The adsorption of Cs(I) and Co(II) by the colloids was a rapid process, and 31.78 and 88.24 mg/g, respectively, were adsorbed at equilibrium. Pseudo-second-order kinetic fitting showed that chemisorption plays a dominant role and acid-base interactions affect adsorption by influencing the stability of colloids and the chemical form of simulated nuclides. This work can be helpful for evaluating the safety of waste repositories.
研究领域:
环境科学
·
放射性废物管理
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2019
·Vol. 12
·期 13
·2115
·
IF 2.972
Wenxin Dong,Xiaolin Pu,Yanjun Ren
As an important industrial material, bentonite has been widely applied in water-based drilling fluids to create mud cakes to protect boreholes. However, the common mud cake is porous, and it is difficult to reduce the filtration of a drilling fluid at high temperature. Therefore, this paper endowed bentonite with a thermo response via the insertion of N-isopropylacrylamide (NIPAM) monomers. The interaction between NIPAM monomers and bentonite was investigated via Fourier infrared spectroscopy (FTIR), isothermal adsorption, and X-ray diffraction (XRD) at various temperatures. The results demonstrate that chemical adsorption is involved in the adsorption process of NIPAM monomers on bentonite, and the adsorption of NIPAM monomers accords with the D–R model. With increasing temperature, more adsorption water was squeezed out of the composite when the temperature of the composite exceeded 70 °C. Based on the composite of NIPAM and bentonite, a mud cake was prepared using low-viscosity polyanionic cellulose (Lv-PAC) and initiator potassium peroxydisulfate (KPS). The change in the plugging of the mud cake was investigated via environmental scanning electron microscopy (ESEM), contact angle testing, filtration experiments, and linear expansion of the shale at various temperatures. In the plugging of the mud cake, a self-recovery behavior was observed with increasing temperature, and resistance was observed at 110 °C. The rheology of the drilling fluid was stable in the alterative temperature zone (70–110 °C). Based on the high resistance of the basic drilling fluid, a high-density drilling fluid (ρ = 2.0 g/cm3) was prepared with weighting materials with the objective of drilling high-temperature formations. By using a high-density drilling fluid, the hydration expansion of shale was reduced by half at 110 °C in comparison with common bentonite drilling fluid. In addition, the rheology of the high-density drilling fluid tended to be stable, and a self-recovery behavior was observed.Keywords:bentonite;N-isopropylacrylamide;drilling fluid;self-recovery
研究领域:
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Minwen Jiang,Na Niu,Ligang Chen
A super-adsorbent bentonite-doped lignin hydrogel spheres (LHS-BT) were synthesized in 2 min via a simple template method to remove cationic dyes in wastewater. In this process, acrylic acid (AA) and 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) are grafted onto lignosulfonate through free radical reaction to construct polymer cross-linking network and enhance the adsorption capacity of lignin. Moreover, polyethersulfone was designed as a template to protect the internal crosslinking and maintain the spherical shape. Then, the template shell was ingeniously removed through heat shrinkage. The shell separation and drying process was completed in one step, reducing the post-processing process. A series of characterization methods were used to evaluate the structural characteristics of LHS-BT. The influences of dye concentration, initial pH value, temperature and contact time on adsorption procedure were systematically studied. The adsorption kinetics and equilibrium adsorption isotherms are in accordance with the pseudo-second-order kinetic model and Langmuir isotherm model, respectively. Adsorption experiments showed that LHS-BT have ultra-high adsorption capacity (2541.76 mg/g for malachite green, 1284.46 mg/g for methylene blue and 1047.72 mg/g for rhodamine B) and faster adsorption rate within 85 min. Additionally, LHS-BT exhibited excellent recyclability without significant efficiency loss for at least five cycles. The mechanism of dyes molecular capture onto LHS-BT might be principally ascribed to electrostatic attraction, π-π interaction and hydrogen bonding. Thus, LHS-BT exhibits great potential for used in efficient, environmental, and economical wastewater remediation. Lastly, it is proved that LHS-BT is suitable for adsorption column to quickly purify wastewater containing dyes.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2017
·
IF 4.233
Liying Jiang,Qichao Ye,Jianmeng Chen,Zhong Chen,Youli Gu
In this study, bentonite–Fe 3 O 4 –MnO 2 composite was synthesized by combining bentonite with Fe 3 O 4 and MnO 2 through co-precipitation. Vibrating-sample magnetometry , scanning electron microscopy with energy-dispersive X-ray spectrometry , transmission electron microscopy , Brunauer–Emmett–Teller measurements, and X-ray powder diffraction techniques were used to characterize the composite. The composite consists of Fe 3 O 4 nanoparticles orderly assembled on the surface of bentonite and an outer layer of MnO 2 sheets. The composite’s particles possess a saturation magnetization of 13.4–30.5 emu/g and a high specific surface area (203.89 m 2 /g). The adsorption behaviors of the composite in Cd(II) removal were evaluated by batch equilibrium experiments. Kinetic and isothermal data fit well the pseudo-second-order and the Freundlich models, respectively. Adsorption reached equilibrium within 30 min, and the Freundlich capacity of the composite was 35.35 mg/g. The adsorption capacity of Cd(II) increased with increasing pH and was dependent on the ionic strength . Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed the combination of surface hydroxyl groups of the composite and Cd(II) in the solution. The prepared composite can be easily recycled and reused by taking advantage of its magnetic properties . The results show that the designed composite is a promising absorbent for the treatment of Cd-contaminated water.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Mingxiang Qv,Jianfeng Bao,Wei Wang,Dian Dai,Qirui Wu,Shuangxi Li,Liandong Zhu
Soil contamination with petroleum significantly threatens the ecological equilibrium and human health. In this context, aerobic co-composting of waste heavy oil with agricultural wastes was performed in the present study to remediate petroleum pollutants through four treatments: CK (control), T1 (petroleum pollutant), T2 (petroleum pollutant with bentonite), and T3 (petroleum pollutant with humic acid-modified bentonite). Comprehensive analyses were conducted to determine the physicochemical parameters, enzymatic activities, removal of petroleum pollutants, microbial community structure, and water-extractable organic matter in different composting systems. Structural equation modeling was employed to identify the key factors influencing the removal of petroleum pollutants. According to the results, petroleum pollutant removal percentages of 44.94%, 79.09%, and 79.67% could be achieved with T1, T2, and T3, respectively. In addition, the activities of polyphenol oxidase (51.21 U/g) and catalase (367.91 U/g), which are the enzymes related to petroleum hydrocarbon degradation, were the highest in T3. Moreover, bentonite addition to the treatment increased the nitrate nitrogen storage in the compost from 10.95 mg/kg in T1 to 18.63 and 17.41 mg/kg in T2 and T3, respectively. Humic acid-modified bentonite could enhance the degree of compost humification , thereby leading to a higher-quality compost product. Collectively, these findings established bentonite addition as an efficient approach to enhance the compost remediation of petroleum pollutants.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
CLAYS AND CLAY MINERALS
·
2024
·
IF 2
Rao-ping Liao,Yong-gui Chen,Chuang Yu,Wei-min Ye,Dong-bei Wu,Cong Liu,Qiong Wang
Compacted bentonite, used as an engineering barrier for permanent containment of high-level radioactive waste, is susceptible to mineral evolution resulting in compromise of the expected barrier performance due to alkaline–thermal chemical interaction in the near-field. To elucidate the mineral-evolution mechanisms within bentonite and the transformation of the nuclide adsorption properties during that period, experimental evolution of bentonite was conducted in a NaOH solution with a pH of 14 at temperatures ranging from 60 to 120°C. The results showed that temperature significantly affects the stability of minerals in bentonite under alkali conditions. The dissolution rate of fine-grained cristobalite in bentonite exceeds that of smectite, with the phase-transition products of smectite being temperature-dependent. As the temperature rises, smectite experiences a three-stage transformation: initially, at 60°C, the lattice structure thins due to the collapse of the octahedral sheets; at 80°C, the lattice disintegrates and reorganizes into a loose framework akin to albite; and by 100°C, it further reorganizes into a denser framework resembling analcime. The adsorption properties of bentonite exhibit a peak inflection point at 80°C, where the dissolution of the smectite lattice eliminates interlayer pores and exposes numerous polar or negatively charged sites which results in a decrease in specific surface area and an increase in cation exchange capacity and adsorption capacity of Eu3+. This research provides insights into the intricate evolution of bentonite minerals and the associated changes in radionuclide adsorption capacity, contributing to a better understanding of the stability of bentonite barriers and the effective long-term containment of nuclear waste.
研究领域:
地质学
·
环境科学
·
核废料管理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）