SEPARATION AND PURIFICATION TECHNOLOGY
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2026
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IF 9.1
Umer Hayat,Shafuq Abbas,Qingcai Yu,Yifan Chai,Defeng Kong,Xinyang Huang,Xing Chen
Nowadays, heavy metals are a major issue worldwide, polluting natural resources. In the given study, a novel approach was developed; commercial coconut shell activated carbon was modified with Fe 3 O 4 and thiourea (CH 4 N 2 S) to adsorb Cr(VI) and Ni(II) from industrial wastewater under photochemical reaction on a signal platform. The Cr(VI) reduction-adsorption rate was approximately 95% (2.91 mg/L), which was investigated under acidic conditions (pH = 2) with a 40 mg dose of adsorbent. The same phenomenon was observed for Ni(II) adsorption, approximately 91% (3.98 mg/L) at pH = 6 for 60 min, using the same adsorbent dose. The increased removal efficiency is attributed to the synergetic behavior of Fe₃O₄ and thiourea, where the Fe₃O₄ endorsed the reduction-adsorption of Cr(VI) while thiourea functional groups ( NH₂ and C S) endorsed the adsorption of Ni(II) with strong coordination of active sites along with surface complexation and electrostatic interactions. Analysis indicated the breakage of the activated carbon structure after the Cr(VI) adsorption. To get insights into the adsorption mechanism, Density Functional Theory calculations were performed to optimize structure, showing the stability of metal and surface complexes. FMO analysis demonstrates a reduction in the HOMO-LUMO energy gap from 2.95 eV (CSAC) to 0.17 eV (CSAC@Fe₃O₄@TU & metal), indicating increased surface reactivity and charge transfer. While NCI and RDG calculations further confirm the electrostatic attraction and bonding of Cr(VI) and Ni(II). This study presents a novel approach to conducting comparative studies under photochemical reactions. The CSAC@Fe 3 O 4 @Tu is a low-cost, green catalyst that was used for the remediation of environmental pollutants.
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JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2026
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IF 4.4
Guanghui Chen,Bolin Li,Zhiguang Xue,Hong Liu,Jiayao Chen,Lei Zhang,Xinguo Xi,Lanqin Tang,Yong Zhou
Constructing well-defined MOF/COF heterostructures that integrate pollutant enrichment with efficient interfacial charge separation remains challenging, as intimate interfacial contact may compromise framework integrity. Herein, an ultrathin TPA-COF/UiO-66-NH₂ heterostructure is fabricated via interfacial self-assembly of exfoliated TPA-COF nanosheets, forming a conformal COF coating while preserving the crystallinity and microporosity of UiO-66-NH₂. Microscopic, thermogravimetric, and nitrogen sorption analyses reveal a continuous ultrathin COF layer with a low yet quantifiable loading (~1.5 wt%) and a BET surface area comparable to that of the pristine MOF. Compared with the individual components and their physical mixture, the assembled heterostructure exhibits markedly enhanced photocatalytic Cr(VI) reduction, highlighting the importance of controlled interfacial integration. Comparative adsorption studies, kinetic modeling, and pH-dependent experiments indicate that Cr(VI) enrichment is closely associated with surface-charge-mediated interactions of the amine-functionalized framework. Suppressed photoluminescence, enhanced photocurrent response, and radical scavenging experiments are consistent with improved interfacial charge separation, with photogenerated electrons serving as the dominant reductive species. Band-edge analysis further suggests a staggered energy alignment that is energetically favorable for interfacial carrier transfer. These findings illustrate how combining functional-group-mediated enrichment with controlled interfacial assembly can cooperatively influence adsorption and charge-transfer processes in MOF/COF heterostructures.
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ACS Sustainable Chemistry & Engineering
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2017
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IF 5.951
Peng Yu,Han-Qing Wang,Rui-Ying Bao,Zhengying Liu,Wei Yang,Bang-Hu Xie,Ming-Bo Yang
Sponge-like chitosan (CS)/reduced graphene oxide (rGO)/montmorillonite (MT) porous composite hydrogels were synthesized with a facile strategy of in situ reduction of graphene oxide (GO) without cross-linking of CS. Integral pore structure can be formed in the hydrogels when proper amount of MT was introduced. The composite hydrogel can restore to the original shape and dimension after compressive deformation like a sponge and show good stability in acid condition. Batch equilibrium measurements on the composite porous hydrogel were carried out to optimize the parameters for the removal of hexavalent chromium ions (Cr(VI)). The results reveal that the Cr(VI) ion sorption of the composite hydrogels is highly pH dependent and is the most effective at pH = 2. The sorption capacity increases with increasing temperature and the maximum Cr(VI) uptake of the composite hydrogel is 87.03 mg/g at 288 K. The sorption follows pseudo-second-order kinetic model and Langmuir isotherm. The composite porous hydrogels can be repeatedly used as adsorbent and a high sorption capacity after repeated usage can be maintained. Such an in situ GO reduction strategy can also be used to fabricate a variety of porous 3D polymer/rGO-based nanocomposites for biomaterials, energy storage materials, and adsorbent materials.
研究领域:
环境科学
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材料科学
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水处理
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纳米复合材料
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吸附技术
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CHEMOSPHERE
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2022
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IF 8.943
Xiao Wang,Yanshi Zhang,Yue Zhang,Chunhua Xu
Leaching and chemical reduction are two commonly used methods for Cr(VI)-contaminated soil remediation. Leaching focuses more on leaching Cr(VI) out of the soil. Chemical reduction has the disadvantages of poor fluidity of reductant. Combining these two remediation methods, this study investigated the performance of Cr(VI)-contaminated soil when H 2 O and citric acid were used as eluant separately and sulfidated zero-valent iron (SZVI) as reductant. And based on the properties of Cr(VI) chelated with –COOH to form a complex and the characteristics of –OH anchored to FeS x , citric acid modified SZVI (Cit-SZVI) was prepared. The prepared Cit-SZVI was characterized by SEM-EDS, XPS, XRD to study its surface properties. The transformation of Cr species in soil was explored by BCR sequential extraction. The results indicated Cr(VI) removal by SZVI was significantly promoted when citric acid as eluant compared with H 2 O. With SZVI dosage of 2.0 wt%, 23.1 mg/L Cr(VI) was basically removed within 60 min when citric acid as eluant, while only 60% Cr(VI) was removed when H 2 O as eluant even after 3 h. The k obs of Cit-SZVI was 1.4 times that of SZVI when H 2 O as eluant. The characterization of Cit-SZVI showed that more FeS x was formed on the surface of the Cit-SZVI, and more –OH of citric acid was anchored to FeS x , leaving –COOH available to chelate Cr(VI). Compared with H 2 O as eluant and SZVI/Cit-SZVI as reducing agent, the removal effect of Cr(VI) was the best when citric acid as eluant and SZVI as reducing agent. BCR sequential extraction showed that Cr(VI) was effectually fixed, weak acid extractable Cr proportion decreased significantly and residual Cr proportion increased in the treated soil. The combination of leaching and chemical reduction proposed in this study can greatly enhance the Cr(VI) removal effect in soil, which is important for the remediation of Cr(VI)-contaminated soil.
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SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Yuxin Liu,Tianye Wang,Ningning Song,Quanying Wang,Yuqing Wu,Ying Zhang,Hongwen Yu
An efficient, simple, and inexpensive N, S-co-doped hydrochar (SNHC) was synthesized from waste straw by a one-pot hydrothermal process without calcination for the removal of Cr(VI). SNHC demonstrated excellent adsorption performance for Cr(VI) and high stability, achieving a high capacity of 171.33 mg/g (293 K, pH 2) and a capacity retention of 82.73 % after five cycles. The adsorption behavior was determined as a multilayer adsorption process based on chemisorption according to the simulation the results of Freundlich adsorption isotherms and pseudo-second-order models. The characterization of SNHC revealed that graphite N and thiophene S formed by the material were the effective active sites, functioning as electron donors to contribute a significant amount of electrons to reduce Cr(VI) to Cr(III). Therefore, next to electrostatic adsorption and complexation, the synergistic reduction of Cr(VI) by graphite N and thiophene S was the main mechanism for Cr(VI) removal. Additionally, density functional theory calculations indicated a low adsorption energy of thiophene S, which increased the attractive interaction between SNHC and Cr(VI) and played the most important role in reducing Cr(VI). The mechanism of the effect of graphite N and thiophene S on Cr(VI) removal not only offered a comprehensive perspective on the role of N, S co-doped mediation in hydrochar but also provided the basic theory for its practical application.
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WATER AIR AND SOIL POLLUTION
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2023
·Vol. 234
·期 2
·1-16
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IF 2.9
Kang Yongfeng,Yu Yingyuan,Zhang Bingqian,Fu Jianning,Jiang Xixi,Jia Baiyun,Men Xiaoling,Li Li
Metal–organic frameworks (MOFs) are ideal adsorbents for wastewater treatment and excellent antibacterial agents. In this study, Cu-NH 2 -MOF chitosan composite microspheres were prepared by the in situ method, and the synthesized microspheres solved the disadvantages of poor recoverability of powder adsorbent and complex operation process. Cr(VI) was removed by adsorption, and the microspheres had a good bacteriostatic effect. The synthesized MOF chitosan composite microspheres were systematically characterized. The adsorption kinetics, isotherms, and thermodynamic properties were appraised, and influences of adsorption conditions toward Cr(VI) adsorption were studied. The kinetic study demonstrated that the adsorption of Cr(VI) by CS@Cu-MOF-M conformed to the pseudo-second-order model. The adsorption isotherms fit the Sips model, and the maximum adsorption capacity of CS@Cu-MOF-M for Cr(VI) was 159.25 mg/g under optimal conditions. The thermodynamic result showed that the removal of Cr(VI) was a spontaneous endothermic process. The adsorption rate of CS@Cu-MOF-M was still more than 80% of that of the first one after four cycles of regeneration experiments. The antibacterial activity results showed that MOF chitosan composite microspheres had good antibacterial properties with MIC value of 0.2 mg/mL and MBC value of 1 mg/mL. These results demonstrated that the synthesized CS@Cu-MOF-M had a great potential to treat wastewater containing Cr(VI) and bacterial contamination. Graphical Abstract
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SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Peiling Han,Jiayin Xie,Xueming Qin,Xinru Yang,Yongsheng Zhao
Micron zero valent iron (mZVI) was an underground remediation material, which had great application potential to replace nano zero valent iron (nZVI) from the perspective of economic and health benefits. However, mZVI was highly prone to gravitational settling, which limited its wide application for in situ remediation of contaminated groundwater. This paper was devoted to develop an efficient and economical groundwater remediation material based on mZVI, which should possess excellent stability, reactivity, and transportability. Thereby xanthan gum (XG) stabilized and Na 2 S 2 O 4 sulfidated mZVI (XG-S-mZVI) was synthesized and characterized with SEM, XRD , XPS , and FTIR techniques. In terms of stability, the adsorbed XG and the dispersed XG worked together to resist the sedimentation of S-mZVI. In terms of reactivity, sulfidation enhanced the electron transfer rate and electron selectivity of XG-S-mZVI, thereby improved the reactivity of XG-S-mZVI. The hexavalent chromium (Cr(VI)) removal rate constant by XG-S-mZVI was determined to be 832.4 times than bare mZVI. In terms of transportability, the transportability of XG-S-mZVI was greatly improved (~80 cm in coarse sand and ~50 cm in medium sand). Straining was the main mechanism of XG-S-mZVI retention in porous media . XG-S-mZVI in situ reactive zone (XG-S-mZVI-IRZ) was only suitable to the media with a grain size larger than 0.25 mm. This study could provide theoretical support and guidance for the implementation of IRZ technology based on mZVI.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
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IF 9.965
Chenrui Liu,He Xiao,Yun Liu,Dejian Li,Hao He,Xiaohan Huang,Wentao Shen,Zhiyan Yan,Zhi Dang,Runliang Zhu
Improving the separation efficiency and transfer ability of photoinduced electrons/holes in pyrite (FeS 2 )-based photocatalytic materials is significant for the photoreduction of hexavalent chromium (Cr(VI)) but still remains a challenge. Herein, a novel homojunction was prepared through in-situ growth of nickel (Ni) doped FeS 2 nanoparticles on FeS 2 nanobelts (denoted as Ni-FeS 2 /FeS 2 ). Systematical characterizations revealed that Ni doped FeS 2 nanoparticles have been successfully in situ grown along the lattice of FeS 2 nanobelts . Photoreduction experiments demonstrated that the Ni-FeS 2 /FeS 2 homojunction with 2 mmol Ni doping contents (denoted as 2Ni-FeS 2 /FeS 2 ) exhibited the optimum Cr(VI) reduction efficiency among the studied catalysts. Density Functional Theory (DFT) calculated results verified that Ni doping could not only be advantageous for the formation of sulfur vacancies but also modify the band gap and band structure of FeS 2 nanoparticles . Moreover, several doping energy levels caused by Ni doping have also appeared near the Fermi level of FeS 2 nanoparticles . The migration paths of electrons and the existence of internal electric field (IEF) in homojunction were further verified by the calculation of work function . To sum up, the doping energy levels and IEF that produced by homojunction played important roles in accelerating the separation efficiency of its photogenerated carriers.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Lili Zhang,Bihui An,Haojie Chen,Jingjing Chu,Jinxia Ma,Yimin Fan,Zhiguo Wang
Catalytic membrane technology, as a combination of membrane separation and catalysis, is a high-efficiency and feasible route for wastewater remediation. The controllable synthesis of ultrasmall metal nanoparticles on the membrane to maximize the size effect is a challenging task yet. Herein, the filter paper-based botryoidal nanolignin channel stabilized ultrasmall PdNP membrane (Pd@LNP/FP) was prepared by chemical crosslinking of epichlorohydrin (EPI), the nanolignin (LNP) serves as both reducing and capping agent for the in-situ synthesis of ultrasmall PdNP with enhanced active sites. The mean size of PdNP was effectively tuned from 1.76 to 2.09 nm by varying the LNP loading amount of composite membranes. The botryoidal LNP supported on FP also provides the nanoscale channel to keep reactants on active sites of ultrasmall PdNP to improve the catalytic performance of Pd@LNP E /FP. The complete removal of hazardous Cr(VI) required only 2.5 min using Pd@LNP E /FP membrane, the pseudo-first-order rate constant (k) is 1.2725 min −1 , much higher than that of the Pd@LNP p /FP membrane prepared by physical composite (0.2885 min −1 ). Moreover, the rapid filtration-catalysis removal of Cr(VI) can be achieved by twice filtration, demonstrating the high efficiency and feasibility of Pd@LNP E /FP via synergetic filtration enrichment and catalysis reduction.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
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IF 5.518
Jun Liu,Hui Wang,Meng-Jie Chang,Meng Sun,Zhi-Wei He,Cong-Miao Zhang,Wen-Yao Zhu,Jia-Liang Chen,Hui-Ling Du,Long-Gui Peng,Zhen-Min Luo,Li Zhang
Magnetically separatable CoFe 2 O 4 /BiOCl (CFO/BOC) fibers were facilely prepared by solvothermal growth of BiOCl on hollow electrospun CoFe 2 O 4 nanofibers in a weak reduction ethylene glycol (EG) solvent for visible light photocatalytic degradation of various contaminants. Due to the defect level resulted from the oxygen vacancies (OVs), evident visible light response and enhanced charge transfer are achieved both for the solo BiOCl spheres and nanosheets on the CoFe 2 O 4 fibrous support. The optimum CFO/BOC synthesized at 160 °C with a precursor concentration of 50 mM shows outstanding photocatalytic activity to degrade different pollutants of Rhodamine B (RhB, 92.9%), Norfloxacin (NOR, 75.5%), and Cr(VI) (78.0%) within 2 h under visible light. The CoFe 2 O 4 nanofibers are not pivotal for the photocatalytic process, but mainly contribute to the photocatalysis as magnetic support, ensuring the CFO/BOC no aggregation and easy collection under an external magnet. In contrast, the OVs play an important role in the visible light absorption , reactive oxygen species generation and redox process during the photocatalytic process. In detail, both photosensitization of RhB and species of h + and·O 2 - contribute to the degradation of RhB, while NOR decomposition is accomplished by three species (h + ,·O 2 - ,·OH). In addition, electrons are the main reactive species for the photoreduction of Cr(VI). Compared to current reported CoFe 2 O 4 /BiOI photocatalysts , significant advances for the CFO/BOC are obtained not only for the cheap BiOCl with OVs for the photocatalytic application, but also much clearer investigation of more details of CFO/BOC photocatalysts such as light absorption, charge transfer and active species for the degradation of various pollutants.
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JOURNAL OF HAZARDOUS MATERIALS
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2021
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IF 10.588
Hao Wang,Shuai Wang,Shixing Wang,Jiali Tang,Yingbi Chen,Libo Zhang
A new zirconium-based adsorption material (UiO-66-AMP) was prepared by modifying UiO-66-NH 2 with 5-adenosine to effectively remove Pb(II) and Cr(VI) from wastewater. The SEM, EDS, XRS and FT-IR characterization confirmed the successful synthesis of UiO-66-AMP. We conducted a sets of experiments to test the adsorption effectiveness of UiO-66-AMP for Pb(II) and Cr(VI). The maximum adsorption capacity of UiO-66-AMP for Cr(VI) (pH=2) and Pb(II) (pH=4) are 196.60 and 189.69 mg/g, respectively. The adsorption process conforms to the pseudo-second-order and Langmuir models, which indicates that the adsorption is a single-layer chemical process. Gibbs free energy ( ∆G) indicates that the adsorption of Pb(II) is an exothermic reaction , while the adsorption of Cr(VI) is an endothermic reaction . At the same time, the adsorbent maintains excellent adsorption capacity at least after 4 cycles. The good adsorption performance of UiO-66-AMP towards the metal ions was attributed to the surface complexation and electrostatic interactions. Therefore, the new adsorbent has obvious application prospect to remove Pb(II) and Cr(VI) from wastewater.
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Journal of Environmental Chemical Engineering
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2021
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IF 5.909
Shaoru Liu,Weizi Zhang,Peng Zhu,Songlin Zuo,Haian Xia
The study reports a facile synthesis of Ag-g-C 3 N 4 /AC composites with highly photocatalytic activity and good adsorption capacity by an impregnation-thermal polycondensation process. The resulting Ag-g-C 3 N 4 /AC composites were used for treatment of different pollutants in water including Rhodamine B (RhB), Cr(VI) ions and pathogens . When the precursor mass ratio of urea and AC was 2:2, the resultant Ag-g-C 3 N 4 /AC catalyst showed the best photocatalytic performances. In particular, the composite photocatalysts exhibited highly bactericidal efficiency, which could reach 99.9% after 120 min of irradiation. The higher photocatalytic performances of Ag-g-C 3 N 4 /AC composites were attributed to the surface plasmon resonance (SPR) effect of Ag nanoparticles (NPs) together with the interfacial synergistic effects. Meanwhile, AC not only exhibited excellent adsorption capacity, but also decreased aggregation of g-C 3 N 4 , which could enhance the separation efficiency of photogenerated charge carriers. It was uncovered through Electron Spin Resonance (ESR) and radical scavenger experiments that • OH radicals, • O 2 − and h + participate in the RhB degradation under the visible light. This work shows that the high-efficient and stable Ag-g-C 3 N 4 /AC composites have a great potential in the treatment of organic pollutants , toxic heavy metals and pathogenic bacteria by adsorption/photocatalysis for practical water treatment .
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