CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Xiao Cheng,Xin Zhong,Chao Li,Shu Zhang,Xun Hu
Bentonite is a commonly used adsorbent material, but micropores in bentonite are generally deficient when compared with typical activated carbon (AC) from biomass. Herein, a facile method was proposed by impregnating bio-oil into bentonite (mixed at different mass ratios) followed by activation with K 2 C 2 O 4 at 800 °C to create additional micropores. The results showed that activation of bentonite (BT) with K 2 C 2 O 4 was difficult, forming AC-BT with S BET of 184.6 m 2 g −1 and little micropores (21.4 %). The activation of the mixture of bentonite and bio-oil with mass ratio of 1: 3 or 1: 1 generated AC-BT 1 /Bio 3 and AC-BT 1 /Bio 1 with much higher S BET (448.1 and 541.2 m 2 g −1 ) and enhanced proportion of micropores (60.2 % and 61.8 %). Further increasing mass ratio of bentonite and bio-oil to 6: 1 and 9: 1 formed the AC-BT 6 /Bio 1 (452.6 m 2 g −1 ) and AC-BT 9 /Bio 1 (339.3 m 2 g −1 ) of lower S BET and reduced proportion of micropores (42.3 % and 33.5 %). The carbon skeleton derived from bio-oil was essential for maintaining the micropores generated. The in-situ IR characterization of the activation process demonstrated importance of aliphatic organics from bio-oil in creating the micropore structures that was the key for efficient adsorption of phenol or tetracycline. Additionally, the bio-oil played the roles as a binder to form clusters-like structures in resulting ACs.
研究领域:
材料科学
·
环境工程
·
吸附技术
·
化学工程
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DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Fangfei Cai,Funing Ma,Xiaoying Zhang,Paul Reimus,Linlin Qi,Yu Wang,Di Lu,Hung Vo Thanh,Zhenxue Dai
The disposal of high-level radioactive waste in deep geological repositories is a critical environmental issue . The presence of bentonite colloids generated in the engineering barrier can significantly impact the transport of radionuclides , but their effect on radionuclide sorption in granite remains poorly understood. This study aimed to investigate the sorption characteristics of strontium (Sr) on granite as well as on the coexistence system of granite and colloids under various hydrogeochemical conditions, through batch experiments. Fourier transform infrared spectroscopy was employed to analyze the sorption forms of Sr on granite before and after sorption. Several hydrogeochemical factors were examined, including contact time, pH, ionic strength, coexisting ions, and bentonite and humic acid colloid concentration. Among these factors, the concentration of bentonite colloids exhibited a significant effect on Sr sorption. Within a specific range of colloid concentration, the sorption of Sr on the solid system increased linearly with the bentonite colloid concentration. pH and ionic strength were also found to play crucial roles in the sorption process. At low pH, Sr sorption primarily occurred through the outer sphere's surface complexation and Na + /H + ion exchange. However, at high pH, inner sphere surface complexation dominated the process. As the ionic strength increased, electrostatic repulsion gradually increased, resulting in fewer binding sites for particle aggregation and Sr sorption on bentonite colloids. The results also indicate that with increasing pH, the predominant forms of Sr in the solution transitioned from SrHCO 3 + and SrCl + to SrCO 3 and SrCl + . This was mainly due to the ion exchange of Ca 2+ /Mg 2+ in plagioclase and biotite , forming SrCO 3 precipitation. These findings provide valuable insights into the transport behavior of radionuclides in the subsurface environment of the repository and highlight the importance of considering bentonite colloids and other hydrogeochemical factors when assessing the environmental impact of high-level radioactive waste disposal .
研究领域:
环境科学
·
放射生物学
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DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2025
·
IF 5.8
Ze-Wei Ke,Yu-Xin Liu,Sheng-Jie Wei,Peng Shen,Kun Yang,Yun-Min Chen,Yu-Chao Li
Per - and polyfluoroalkyl substances (PFAS) pose significant environmental and human health concerns due to their extreme persistence and bioaccumulation potential, and widespread contamination. Conventional clay-based barriers, such as geosynthetic clay liners, exhibit limited PFAS containment capabilities owing to their inherently low adsorption capacity. To overcome this challenge, this paper synthesized hexadecyltrimethylammonium-modified bentonite (HDTMA-NaB) as a high-performance adsorbent for engineered containment applications. Comprehensive batch adsorption experiments demonstrated that HDTMA-NaB achieves substantially greater PFAS adsorption capacity compared to pristine bentonite, with adsorption kinetics following a pseudo-second-order model and isotherms were well-described by both Langmuir and Freundlich models. Molecular dynamics simulations unveiled a distinctive “head-attracted, tail-parallel” adsorption configuration, where PFAS molecules align with HDTMA surfactants within montmorillonite interlayers. Chain-length-dependent adsorption patterns were observed, with short-chain PFAS preferentially adsorbing at clay particle edges while long-chain PFAS penetrated deeper into interlayer spaces. Potential of mean force analysis quantitatively verified stronger adsorption affinity for long-chain PFAS, consistent with adsorption experiment observations, through deeper and more numerous energy minima. Thermodynamic analysis indicated that PFAS adsorption was driven by both enthalpic and entropic contributions, with entropy playing the dominant role. The entropic contribution primarily arose from hydrophobic interactions between PFAS fluorinated carbon chains and HDTMA alkyl chains, providing a mechanistic explanation for the observed chain-length-dependent adsorption behavior in adsorption experiments. Meanwhile, the enthalpic contribution arose from electrostatic attraction between PFAS anionic headgroups and HDTMA cationic trimethylammonium groups. These molecular-scale insights provide a fundamental basis for designing high-performance clay-based containment systems for PFAS mitigation.
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产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 11
·1891
·
IF 4.329
Zongkun Lin,Yuru Yang,Zizhan Liang,Lei Zeng,Aiping Zhang
In order to avoid the secondary pollution of the toxic residue of chemical crosslinking agent accompanied by chemical hydrogel adsorbent and enhance the adsorption performance of physical hydrogel, chitosan/calcium alginate/bentonite (CTS/CA/BT) composite physical hydrogel was constructed. The formation mechanism and structure of the composite hydrogel were determined by FTIR, XRD and SEM. Adsorption performances of the hydrogel toward Pb2+, Cu2+and Cd2+in water under different condition as well as multi-ion competitive sorption were investigated. The adsorption processes were described with the canonical adsorption kinetics and isotherms models. With the utilization of XPS analysis and adsorption thermodynamics analysis, it was found that the adsorptions were spontaneous physico-chemical adsorptions. The results showed that the maximum adsorption capacity of the hydrogel for Pb2+, Cu2+and Cd2+reached up to 434.89, 115.30 and 102.38 mg·g−1, respectively, better than those of other physical hydrogels or chitosan/bentonite composite. Moreover, the composite hydrogel improved the collectability of bentonite and showed a good reusability. The modification of bentonite and the formation of hydrogel were completed simultaneously, which greatly simplifies the operation process compared with the prior similar works. These suggest that the CTS/CA/BT composite hydrogel has promising application prospects for removal of heavy metal ions from water.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Hui Wang,Chongrui Zhang,Lusha Jiang,Shan Tong,Yu-Chao Li,Hefu Pu,Qiang Zhao
Calcium bentonites (CaB), rich in European and Asian countries, are potential barrier materials for landfill leachate containment. However, CaB has to be converted into sodium bentonite (NaB) by Na-activation so as to facilitate intercalation modification. In this study, salt-resistant poly(acrylic acid-N, N-diethyl acrylamide) [P(AA-DEA)] was designed to intercalate and graft CaB by in situ polymerization without prior Na-activation. By this design, acrylic acid monomers were first adsorbed into interlayers of Ca-montmorillonite (Ca-MT) through the electrostatic complexation with Ca 2+ , dislodging Ca 2+ from montmorillonite surfaces. Then, ammonium ions of N, N-diethyl acrylamide were adsorbed into Ca-MT interlayers. Swelling index of the obtained CaB/P(AA-DEA) nanocomposite in aggressive coal combustion product (CCP) leachate is 15.8 mL/2g, which is as high as 3.4 times that of CaB. CaB/P(AA-DEA)-based geosynthetic clay liners (GCLs) exhibit very low hydraulic conductivity (1.6✕10 −12 m/s) to CCP leachate, which is as low as 3.3% that of the U.S. standard requirement and ∼4 orders of magnitude lower than that of CaB-based GCL. Polymer elution of CaB/P(AA-DEA)-8% in CCP leachate is as low as 1.9% that of the dry mixed samples.
研究领域:
环境工程
·
材料科学
·
土木工程
·
高分子化学
·
地质屏障材料
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DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Pan Hu,Jing Wang,Ruihua Huang
In this study, batch adsorption study was utilized in evaluating the potential suitability of quaternized chitosan immobilized bentonite (BT) as an adsorbent in the adsorption of anionic pollutants, Cr(VI), and methyl orange (MO) from aqueous solutions. The adsorptive behaviors of Cr(VI) and MO were examined as a function of the ratio of quaternized chitosan to BT, adsorbent dosage, solution pH, initial Cr(VI) (or MO) concentration, and contact time. The adsorption equilibrium for both Cr(VI) and MO was reached quickly. Adsorption isotherms for Cr(VI) and MO were well described by the Langmuir isotherm, while the pseudo-second-order kinetic model provided good kinetic data fitting. Furthermore, the results show that this adsorbent exhibited higher adsorption capacity for MO than Cr(VI). It appears that this anionic Cr(VI) favored the electrostatic interactions with this adsorbent while the anionic MO dye may interact with this adsorbent by electrostatic interactions and the hydrogen bonding.
研究领域:
环境科学
·
吸附技术
·
水处理
·
聚合物复合材料
·
污染物去除
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2026
·
IF 7.7
Rong Guo,Lina Wang,Di Zhang,Chuanhui Jiang,Guoxiu Qian,Yonggang Wu
Waste activated sludge (WAS) produced in the industrial process is major pollutants, which has gained extensive attention. Appropriate treatment and resource utilization are of great significance to the economy development and environment protection. Herein, a novel strategy using WAS coupled with bentonite (BT) to synthesize mineral-carbon nanosheets (MCN) to enhance dye adsorption was proposed. The results demonstrated BT promoted the pyrolysis of WAS, thereby forming a sheet-like structure and construction of C-O-Si/ C-O-Al sites on the surface. This composite exhibited enhance adsorption performance for dye methylene blue (MB) with a kinetic (0.000314 mg/(g/min)) and equilibrium adsorption capacity (90 mg/g), compared with those of activated carbon (0.000423 mg/(g/min)) and 25.6 mg/g). Spectroscopic tests indicated that C-O-Si/ C-O-Al sites were dominate sites and the sheet-like structure could expose these sites, thus increasing the adsorption performance. This study demonstrates that WAS is an effective low-cost raw material for carbon adsorbent, offering a sustainable strategy for resource utilization of WAS and environmental remediation, achieving the goal of “treating waste with waste”.
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产品关联
DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2024
·
IF 6.7
Dayong Luo,XiaoSong Tian,Ruxiang Qin
Iron reducing bacterium Acidiphilium cryputum JF-5 was used to biologically load lanthanum on bentonite (BLB) to remove arsenic(V) from solution. By biological reductive release of iron from bentonite and lanthanum loading, new lanthanum-loaded bentonite was prepared and the adsorption efficiency of arsenic(V) was improved from 7.87 mg/g to 22.69 mg/g in bath experiment. The mobilization of the dispersed biologically loaded lanthanum bentonite particles can be described by the Convection-Dispersion Equation. The breakthrough ability of biologically lanthanum-loaded bentonite (BLB) increased by 5.5 times when increasing flow velocities from 90 mL/h to 360 mL/h. When injected BLB into arsenic(V)-containing pre water of quartz column, the concentration of arsenic(V) could quickly decrease the initial concentration of arsenic(V) from 2000 μg/L to lower than limit for drinking water and keep relative stable. Meanwhile, the hydraulic conductivity of treatment system is also improved compared to prinstine bentonite due to iron-deficient in BLB. The results suggest that biologically load lanthanum bentonite may be an effective modified mineral for remediating arsenic(V)-containing soil.
研究领域:
环境科学
·
微生物学
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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
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DOI
高影响因子
Journal of Rock Mechanics and Geotechnical Engineering
·
2025
·
IF 10.2
Lusha Jiang,Hui Wang,Yu Miao,Qiang Zhao,Ming Min,Jinwei Qiu,Hefu Pu
Polymer-modified bentonite (PMB) is much more effective at containing chemically aggressive liquids than conventional bentonite. The PMB manufacturing process typically utilizes natural, high-quality sodium bentonite (NaB) owing to its excellent hydrophilicity and swelling capacity. However, calcium bentonite (CaB), which is much more abundant worldwide, is rarely used for containment applications owing to its poor hydrophilicity. This study proposed a polymerization method that transforms sodium-activated calcium bentonite (NCB) into PMB to achieve low hydraulic conductivity ( k ) to aggressive liquids. The mechanism for its low k was revealed through characterization techniques and analyses (e.g. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET)). The results showed that the PMB had a small amount of polymer elution (indicating better interface stability) and thus exhibited excellent barrier properties under chemically aggressive conditions, with the k of < 10 -11 m/s for 0.6 mol/L NaCl solution, which is four orders of magnitude lower than that of the NCB ( k = 3×10 -7 m/s). Various microscopic analyses indicated that the selected monomers were successfully polymerized, and intercalated into and grafted onto the montmorillonite layers of bentonite. The formed polymer network increased the swelling capability of PMB granules, decreased the pore size, and created narrow and tortuous flow pathways leading to a very low k to aggressive liquids.
研究领域:
材料科学
·
环境工程
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产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2018
·
IF 0
Xin Liang Li,Guan Cheng Jiang
In this study, a cationic gelatin derivative (denoted as GCTA) was synthesized and its effect on the swelling of sodium bentonite (Na-BT) was investigated. The inhibitive properties of GCTA were evaluated through linear swelling test and hot-rolling recovery test. Results suggested that GCTA displayed better inhibitive ability than KCl and polyether amine (PEA). The underlying inhibitive mechanisms were also investigated by measuring interlayer spacing through X-ray diffraction, observing shale cuttings through scanning electron microscope and measuring the change of zeta potential of Na-BT dispersion. GCTA could strongly adsorb on the surface of clay particles and coat the particles. Meanwhile, the molecules entered the interlayer space, expelled water and decreased the interlayer spacing. This study can provide new insights into the design of environmentally friendly and highly effective clay inhibitors for water-based drilling fluids.
研究领域:
材料科学
·
地质学
·
环境科学
✓ 已验证
产品关联
DOI
Journal of Inorganic and Organometallic Polymers and Materials
·
2016
·Vol. 27
·期 1
·249-256
·
IF 1.308
Du Sen,Wang Luyan,Xue Ni,Wu Ting,Pei Meishan,Sui Weiping,Guo Wenjuan
Modified bentonite was prepared by grafting poly(2-(acryloyloxy)ethyl)trimethyl ammonium chloride by a Ce(IV)-redox process to remove an anionic dye, brilliant yellow (BY). The BY removal efficiency changed with pH, temperature and reaction time. The adsorption capacity for BY decreased slightly with value of pH enhanced from 2.0 to 10.0 in solution. Kinetics models and isotherms models were used to match the adsorption behavior. Adsorption kinetics showed the adsorption was a fast course, achieving balance within 180 min and could be described well by the pseudo-second-order model. The thermodynamic equilibrium data showed that the adsorption isotherm matched with Langmuir model. Results represented that the adsorption capacity increased greatly by grafting PDAC on bentonite and the maximum adsorption capacity could reach to 302.9 mg/g.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）