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
COLLOID AND POLYMER SCIENCE
·
2017
·Vol. 295
·期 7
·1165-1175
·
IF 1.723
Meng Fanqiu,Wang Luyan,Pei Meishan,Guo Wenjuan,Liu Guoran
The polyaniline-bentonite composite (Bent−APTES−PANI), as a novel adsorbent for anionic dyes, was successfully synthesized by the oxidative polymerization method using ammonium persulfate as an oxidant. The prepared samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), zeta potential, scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). Our results indicated that the polyaniline was successfully grafted on the surface of bentonite. The positive charge on the surface of the adsorbent was generated by using amino-activated bentonite (Bent−APTES) grafted with the polyaniline doped with citric acid. The adsorbent was applied to remove metanil yellow (MY) from aqueous solution. The adsorption process is hardly influenced by pH, because there are many amino groups (−NR 3
+ ) on the surface of the adsorbent. And the maximum adsorption capacity of Bent−APTES−PANI is 444.44 mg g −1 , which is better than other materials. Furthermore, the adsorption kinetics study of MY onto Bent−APTES−PANI obeyed pseudo-second-order model and the adsorption isotherm data were fitted well by Langmuir isotherm. The results of this study suggest Bent−APTES−PANI is a promising material for anionic dye removal.
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
Sustainability
·
2022
·Vol. 14
·期 3
·1318
·
IF 3.889
Haijie He,Erpei Xu,Zhanhong Qiu,Tao Wu,Shifang Wang,Yuhua Lu,Guannian Chen
Bentonite was modified with cetyltrimethylammonium bromide (CTAB). The organically modified bentonite (OMB) was used to remove phenol from aqueous solution, the microstructural changes were characterized by X-ray diffraction (XRD) and scanning electronic microscopy (SEM), and phenol adsorption kinetic was obtained using batch adsorption test results. The results indicated that the rate of adsorption of phenol onto the OMB was positively correlated with the initial concentration, and the maximum adsorption capacity was found to be 10.1 mg/g at the initial concentration of 150 mg/L at 25 °C and pH 10. The investigations of adsorption kinetics models showed that the adsorption kinetic was better reflected by the pseudo-second-order kinetic model. Furthermore, the properties of the OMB samples with different adsorption times were obtained by SEM and XRD. The statistic analysis revealed that the pore diameter of the OMB samples decreased with the increasing adsorption time and gradually reached equilibrium.Keywords:organically modified bentonite;adsorption;kinetics
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
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Dongliang Yang,Feipeng Cheng,Le Chang,Dengfeng Wu
Developing efficient and low-cost adsorbent for removing heavy metal ions from aqueous solution is of great significance for environmental protection. Herein, low quality natural bentonite was purified and sodium-modified to adsorb Pb 2+ from the aqueous phase. The effects of initial pH value of the solution, type and amount of the adsorbent, contact time and initial Pb 2+ concentration on the adsorption performance of sodium bentonite were systematically studied. The adsorption efficiency of sodium bentonite was significantly better than that of purified bentonite and natural bentonite toward Pb 2+ . Under the optimum adsorption conditions of pH = 5, adsorbent dosage of 0.2 g, initial Pb 2+ concentration of 400 mg/L, and adsorption time of 120 min, sodium bentonite can remove more than 99.94% of Pb 2+ . Adsorption behavior fitted well with Freundlich isotherm and pseudo-second-order kinetics adsorption equations. Adsorption process was endothermic and feasible. The adsorption pathways of Pb 2+ on sodium bentonite are mainly including ion exchange, surface hydroxyl functional group capture, electrostatic attraction and chemical precipitation by CO 3 2- in the pore channel to form PbCO 3 . This research is anticipated to give technical support for prompting the wider application of bentonite as an adsorbent material.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 12
·4058
·
IF 3.748
Haijie He,Kuan Chai,Tao Wu,Zhanhong Qiu,Shifang Wang,Jie Hong
Organic dye rhodamine B is one of the common organic pollutants in the water and soil environment. This study investigated the feasibility of removing rhodamine B from an aqueous solution through adsorption by kaolin, kaolin-sodium bentonite, and kaolin-organic bentonite. Batch adsorption test results showed that the maximum adsorption quantities of kaolin, kaolin-sodium bentonite, and kaolin-organic bentonite were 7.76 mg/g, 11.26 mg/g, and 12.68 mg/g, respectively, implying that the addition of bentonite to kaolin can effectively improve its adsorption capacity for rhodamine B. Moreover, the Langmuir isotherm model is suitable to describe the adsorption of rhodamine B by kaolin and kaolin-sodium bentonite, while it is preferable to use the Freundlich isotherm model in the case of kaolin-organic bentonite. The adsorption kinetic characteristics of rhodamine B, by these three adsorbents, are suitable to be described with a pseudo-second order kinetic model. Furthermore, the characteristics of the above three adsorbents were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The above results indicated that kaolin and organic bentonite can be used to design efficient adsorbents for organic pollutants similar to rhodamine B.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Huilin Zhang,Xiaoyu Liang,Chao Yang,Chunge Niu,Jide Wang,Xintai Su
Nano γ-Fe 2 O 3 modified bentonite magnetic composites (γ-Fe 2 O 3 /Bent) were synthesized via an annealing approach of the ferric oleate and bentonite compounds. The γ-Fe 2 O 3 nanoparticles with narrow size distribution and an average diameter of 32 nm were equably dispersed on the surface and between layers of the bentonite nanosheets , which mainly owed to the complete mixture of ferric oleate and hydrophobic modified bentonite. The γ-Fe 2 O 3 /Bent composites exhibited typical ferromagnetic characteristics with the saturation magnetization of 22.31 emu/g and coercivity of 209 Oe. Adsorption performance measurement indicated that the γ-Fe 2 O 3 /Bent composites are a kind of excellent adsorbent with fast adsorption rate, high adsorption capacity, 99.99% removal rate and easily magnetic separation process for the removal of cationic dye methylene blue (MB). Adsorption kinetics and isotherms were studied to describe the adsorption process , and the electrostatic adsorption mechanism was confirmed by zeta potential measurement.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
DESALINATION
·
2026
·
IF 9.9
Jianyun Liu,Junsheng Wu,Yue Zhu,Boshuang Zhang,Jianmao Yang
GO is electrostatically assembled on Fe-pillared bentonite at mild conditions. • The optimized GO/PB electrode delivers a desalination capacity of 41.11 mg g −1 in 10 mM NaCl. • A balanced GO loading improves conductivity without blocking ion-accessible pores. • The electrode retains 91.12% capacity after 100 CDI cycles. • Real groundwater desalination achieves >85% removal for major ions. Bentonite is an abundant layered clay mineral with intrinsic negative charge and ion-exchange capability, but its direct use as a capacitive deionization (CDI) electrode is restricted by poor electrical conductivity. In this work, graphene oxide-encapsulated Fe-pillared bentonite (GO/PB) composites were prepared through a mild electrostatic self-assembly strategy. Fe pillaring enlarged the interlayer space and exposed ion-accessible surfaces, while cationic surfactant-assisted assembly enabled negatively charged GO sheets to uniformly anchor onto the pillared bentonite surface. The resulting composite integrated the structural stability and cation-affinity of pillared bentonite with a uniformly assembled GO-PB interface, providing more efficient charge transfer and desalination than the physically mixed counterpart. The optimized GO/PB-0.2 with 14.6% GO delivered a salt adsorption capacity of 41.11 mg g −1 in 10 mmol L −1 NaCl and achieved 59.77 mg g −1 in 50 mmol L −1 NaCl. The capacity still maintained 91.12% after 100 continuous cycles, with no obvious change in the crystalline structure. Desalination tests using actual groundwater further showed simultaneous removal of multiple ions with removal efficiencies above 85%. This work demonstrates that charge-directed interfacial assembly provides an effective strategy for improving the electrical accessibility and utilization of pillared-clay ion-storage domains, offering a mild route for developing low-cost and stable CDI electrodes for brackish-water treatment. Download: Download high-res image (146KB) Download: Download full-size image
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Yinggang Jia,Ronghao Man,Liannan Shang,Jian Chen
Developing an environmentally friendly adsorbent with high adsorption capacity and economic advantages is crucial for the treatment of cadmium (Cd)-contaminated wastewater. In this study, Bentonite (Bt), which is widely distributed in nature, was used to prepare a new type of chitosan (CS)-grafted polymerized aluminum-pillared bentonite (i.e., Al@Bt): CS@Al@Bt. This new material effectively addresses the issues of chitosan’s poor mechanical strength , limited load capacity, and the weak adsorption properties of raw bentonite for Cd. The effects of synthesis conditions on Cd adsorption by modified bentonite were investigated through batch experiments. The adsorption mechanism was revealed by characterization tests such as X-ray diffraction (XRD), N 2 adsorption-desorption experiments, Scanning and Transmission electron microscopy (SEM-TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results showed that compared to raw Bt, when the ratio of Al in polymerized aluminum to the cation exchange capacity (CEC) of Bt was increased to 5 (i.e., Al/CEC=5), the specific surface area (SSA) of Bt increased from 78.46 m²/g to 195.99 m²/g. Additionally, the interlayer spacing and total pore volume increased by 1.22 and 1.13 times, respectively. After grafting chitosan onto Al@Bt, CS@Al@Bt reached adsorption equilibrium rapidly within 15 min, achieving a removal rate of up to 99.82% (initial concentration of Cd(II) was 20 mg/L, and the solid-liquid ratio was 1 g/L). Additionally, CS@Al@Bt showed good adsorption performance over a wide pH range. The rich pore structure of CS@Al@Bt and the complexation between amino (-NH 2 ) and hydroxyl (-OH) groups with Cd(II) were the main mechanisms for the removal of Cd(II) from the solution. The application showed that CS@Al@Bt effectively reduced Cd-containing mining wastewater from class V to class II quality, underscoring its significant potential for treating Cd(II)-contaminated wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Environmental Earth Sciences
·
2025
·Vol. 84
·期 20
·1-15
·
IF 2.8
Che Chi,Bi Yu-Zhang,Sun Xin-Po,Feng Zhen,Ma Tian-Xing,Jiang Zhe-Yuan,Fu Xian-Lei
Zinc (Zn) is a prevalent contaminant, with the highest concentration and exceedance rate among heavy metals in groundwater surrounding tailing ponds in China. Bentonite is the primary material used for soil-bentonite vertical cutoff walls, which are essential for preventing the migration of contaminated groundwater. This study investigates the swell and hydraulic performances of guar gum (GG), polyacrylamide (PAM), and carboxymethyl cellulose (CMC) amended bentonite in Zn-contaminated groundwater, aiming to identify the optimal polymer amendment. Modified fluid loss (MFL) tests were conducted to compare the hydraulic conductivity ( k ) of unamended and amended bentonite slurries in deionized water (DW) and Zn(NO 3 ) 2 solutions at various concentrations. The free swell index (FSI) of the bentonites was measured through free swell tests. Additionally, the effect of polymer dosage on FSI and k was examined, and the results were compared with those of unamended and polymer-amended bentonites reported in previous studies. The results revealed that the FSI of the amended bentonites was higher, while their k was lower compared to unamended bentonite across all concentrations of Zn(NO 3 ) 2 solutions. Notably, CMC-amended bentonite (CB) exhibited the lowest k , which was 1 to 2 orders of magnitude lower than that of unamended bentonite. The swell and hydraulic performances of CB improved with increasing dosage under various concentrations of Zn(NO 3 ) 2 solutions. Furthermore, a clear linear negative correlation was observed between k and FSI for CB at lower dosages. These findings are of great practical significance for constructing cutoff walls in contaminant containment project for Zn-contaminated sites.
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Hong Zhang,Bo Wang,Xu Zeng,Xin Zhang,Bo Ren,Xiaodong Yang
In view of the increasingly severe environmental hazards posed by traditional plastic packaging materials, this study develops a biodegradable chitosan (CS) film to address deficiencies in water solubility and mechanical properties, thereby promoting its wide application in the field of food packaging. A novel antioxidant, antibacterial, and biodegradable food packaging film was synthesized using natural bentonite (Bt) and gallic acid (GA) - mediated silver nanoparticles (AgNPs). This is the first study to integrate Bt, GA, and in-situ-synthesized AgNPs into chitosan films for synergistic antioxidant/antibacterial enhancement. Specifically, chitosan was modified with gallic acid, which significantly improved the water solubility of chitosan. Subsequently, GA reduces Ag + in situ to form AgNPs using the modified chitosan. SEM analysis indicated that the diameter of the synthesized AgNPs ranged from 30 to 100 nm. By means of the solution casting method, the modified chitosan was compounded with AgNPs and Bt. CSGA/Bt/AgNPs film exhibited excellent water vapor and ultraviolet (UV) barrier properties. In terms of mechanical properties, the strength of the pure CS film was 17.28 MPa, while that of the CSGA/Bt/AgNPs film reached 18.56 MPa, indicating a good interaction among CS, GA, Bt, and AgNPs. Experimental results demonstrated that the film had significant antibacterial activity against S. aureus and E. coli , demonstrating great application potential in the field of food packaging.
研究领域:
食品科学
·
纳米技术
·
高分子科学
·
材料工程
·
环境科学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2024
·
IF 4.4
Haixiang Shi,Yiyuan Xu,Tongming Su,Xuan Luo,Xinling Xie,Zuzeng Qin,Hongbing Ji
The surface acidity and structure of catalysts play crucial roles in cinnamaldehyde (CAL) selective hydrogenation to manufacture cinnamyl alcohol (COL). Herein, a Co–Fe-supported acidified bentonite catalyst (Co–Fe/ACBT) was prepared via sulfuric acid treatment of bentonite (BT) and the traditional impregnation method. The combination study, including FT-IR spectra of adsorbed pyridine and ammonia temperature-programmed desorption (NH3-TPD), showed that Co–Fe/ACBT has vast acidic sites mainly originating from surface unsaturated metal sites of ACBT, which prefer to adsorb polar >CO but not nonpolar >CC<. X-ray photoelectron spectroscopy (XPS) verified that the effect of electron transfer was significantly enhanced when the active metal was loaded on ACBT, leading to an increase in the electron cloud density of the Co species, which promoted the activation of >CO. Due to the modified electronic properties of Co species and abundant acidic sites, Co–Fe/ACBT exhibited a 90.5% conversion and 86.8% hydrogenation selectivity from CAL to COL, which are notably greater than those of the Co–Fe-supported bentonite catalyst (32.0% CAL conversion and 66.4% COL selectivity).
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
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Qi Wang,Baker Rhimi,Hui Wang,Chuanyi Wang
To solve the aggregation problem of TiO 2 nanomaterials and improve the catalytic efficiency, F-doped TiO 2 /exfoliated bentonite (TF/EB) composite was prepared by dispersing F-doped TiO 2 (TF) nanoparticles on an exfoliated bentonite (EB) using a facile sol–gel method. The exfoliated bentonite was prepared by liquid-exfoliation method from the natural bentonite (B). The prepared samples were applied for toluene degradation in gas phase under UV and visible light irradiation. The as-prepared TF/EB composite exhibited higher toluene degradation efficiency than that of pure TiO 2 , F-doped TiO 2 and TF/B composite. Results indicated that the calcination temperature and the initial F/Ti atom ratio of reaction precursors greatly affected the photocatalytic activity towards toluene degradation. The best photocatalytic performance was obtained by the sample calcinated at 400 °C with an initial F/Ti atom ratio of 5%. The improved photocatalytic performance is ascribed to a series of benefits introduced by F-doping and exfoliation process. The presence of F - ions increases the percentage of exposed reactive {0 0 1} facets on TiO 2 . Moreover, F - ions incorporated into the TiO 2 lattice generate oxygen vacancies and Ti 3+ defects, which influence the transfer and migration of the photoinduced charge carriers and induce a visible-light photocatalytic activity . Furthermore, the electrostatic interaction of negatively charged exfoliated bentonite surface leads to a more efficient separation of charge carriers.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 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）