ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2020
·
IF 7.864
Shishu Zhu,Xiaochen Huang,Xiaobao Yang,Peng Peng,Zhipeng Li,Chao Jin
Redox processes mediated by biochar(BC) enhanced the transformation of Cr(VI), which is largely dependent on the presence of PFRs as electron donors. Natural or artificial dopants in BC’s could regulate inherent carbon configuration and PFRs. Until recently, the modulation of PFRs and transformation of Cr(VI) in BC by nonmetal-heterocyclic dopants was barely studied. In this study, changes in PFRs introduced by various nitrogen-dopants within BC are presented and the capacity for Cr(VI) transformation without light was investigated. It was found N-dopants were effectively embedded in carbon lattices through activated-Maillard reaction thus altering their charge and PFRs. Transformation of Cr(VI) in N doped biochar relied on mediated direct reduction by surface modulatory PFRs. The kinetic rate of transformation of Cr(VI) was increased 1.4–5 fold in N-BCs compared to nondoped BCs. Theortical calculation suggested a deficiency in surface electrons induced Lewis acid–base bonding which could acted as a bridge for electron transfer. Results of PCA and orbital energy indicated a colinear relationship between PFRs and pyrrolic N, as well as its dual-mode transformation of Cr(VI). This study provides an improved understanding of how N-doped BC contributes to the evolution of PFRs and their corresponding impacts on the transformation of Cr(VI) in environments.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Xu Yang,Yuhong Zhou,Zhaojie Sun,Chunhui Yang,Dongyan Tang
ZIF-8@ZIF-8/PAN nanofibers were fabricated by the incorporation of zeolitic imidazolate frameworks (ZIFs) with electrospun polyacrylonitrile (PAN) nanofibers, and following by the in-situ growth of ZIFs onto the surface of the nanofibers. The abundant micropores and active sites of ZIFs supplied the effective adsorption and reduction to heavy metal ions of Cr(VI). The obtained novel nanofibers overcome the crystal agglomeration of ZIF-8 effectively and maintained the porous structures by the nanofibrous morphology of PAN and the evenly distributed ZIF-8, and thus exhibited relative higher surface area (871.0 m 2 g −1 ) and excellent loading efficiency of ZIF-8 (82.9 %). As target adsorbate, Cr(VI) could be removed from aqueous media effectively with the maximum adsorption capacity ( q max ) of 39.68 mg g −1 , and with better recyclability. Significantly, guided with the proposed feasible adsorption-reduction mechanism of Cr(VI), toxic Cr(VI) ions could be further reduced partially to the relative harmless Cr(III). Potentially, the present stable and advantageous approach to loading and growing metal organic frameworks (MOFs) onto electrospun nanofibers could be extended to other water-stable MOFs and to remove various heavy metal ions.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Shan-Shan Li,Xue-Lian Wang,Qing-Da An,Zuo-Yi Xiao,Shang-Ru Zhai,Li Cui,Zhong-Cheng Li
Considering that the hazardous heavy metal ions like Cd(II) and Cr(VI) are widely present in the environment, nowadays employing easy-to-handle adsorption-oriented processes are feasible choices towards efficient remediation of Cd(II) and Cr(VI) from aqueous systems. Herein we developed a novel amino-functionalized bead with cost-effectiveness, high sorption capacity and fast sorption kinetics to remove Cd(II) and Cr(VI) from aqueous solution. The carboxyl methylcellulose and chitosan-derived nanostructured sorbents synthesis were mainly through chitosan and dopamine self-polymerization, doped in sodium carboxymethyl cellulose, and glutaraldehyde cross-linking. The pH value, initial concentration and contact time were investigated. Experimental data were commendably described by Freundlich isotherm and Pseudo-second-order model. The maximum adsorption capacities of Cd(II) and Cr(VI) obtained from the experimental data were 470.0 mg/g and 347.0 mg/g, respectively. The adsorbents were collaboratively characterized by FT-IR, SEM, TGA , XPS , etc., and the adsorbent basically exhibited high complexation ability to Cd(II) and showed strong electrostatic effect with Cr(VI) under acidic conditions. The recycling characteristics suggested that it possesses an outstanding recyclability. The adsorbent may have a potential as high-value biological adsorbent to remove heavy metals and it deserves further research into the practical application.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Nano
·
2019
·Vol. 7
·期 1
·286-303
·
IF 7.704
Changlin Yu,Debin Zeng,Qizhe Fan,Kai Yang,Julan Zeng,Longfong Wei,Junhui Yi,Hongbing Ji
A powerful photocatalyst is the key for photocatalytic environmental purification via sunlight harvesting and utilization. In this work, novel boron doped Sn3O4 microspheres constructed from nanoplates were designed and fabricated. Density functional theory (DFT) studies were carried out to investigate the boron doping mechanism, in which DFT predicted that boron doping would enhance the light harvesting capability and the photo-response of Sn3O4, which was proved by diffuse reflectance spectra (DRS) and transient photocurrent responses. Attributed to its unique porous structure, and enhanced light harvesting and high carrier utilization capabilities, the boron doped Sn3O4 microsphere exhibited high efficiency for Cr(IV) removal and azo dyestuff degradation. Moreover, an unexpected synergistic effect upon simultaneous removal of phenols (phenol, bisphenol A and p-chlorophenol) and Cr(VI) was observed.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Lelin He,Deshun Huang,Zexiang He,Xiaojiao Yang,Guozong Yue,Jing Zhu,Didier Astruc,Pengxiang Zhao
MXenes, as new members of the 2D materials group, are regarded as good candidates for heavy metal removal particularly for radioactive metal element because of their high irradiation stability. However, the small interlayer distance and lack of active sites on the surface limit their further application. In this report, nanoscale zero-valent iron has been introduced into the inter-layer structure of alkaline intercalated Ti 3 C 2 (Alk-Ti 3 C 2 ) and investigated to Cr(VI) removal. The XPS spectra, SEM images, TEM images, and N 2 adsorption-desorption isotherms characterizations revealed that the OH groups on the Alk-Ti 3 C 2 surface assisted the introducing of nZVI into the inter-layer of Alk-Ti 3 C 2 and subsequently stabilized the nZVI. The increased active sites of nZVI and extended interlayer space of Alk-Ti 3 C 2 could improve the uptake capacity of Cr(VI) (194.87 mg/g at pH = 2). The highly efficient removal of Cr(VI) was maintained even in the presence of coexisting cations, which showed great potential for real environment remediation. Mechanistic study indicated that the synergistic effects of nZVI and Alk-Ti 3 C 2 nanosheet in nZVI-Alk-Ti 3 C 2 composites are keys for Cr(VI) removal.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENT INTERNATIONAL
·
2019
·
IF 7.943
Shibin Liu,Shengyan Pu,Daili Deng,Hongyan Huang,Chun Yan,Hui Ma,Bahar S. Razavi
Chromium (Cr) contamination is especially hazardous to soil biota. Application of manure and biochar has been frequently proposed to remediate Cr-contaminated soil. However, the understanding of mechanisms behind manure and biochar impacts on soil enzyme activities requires advanced visualization technologies. For the first time, we compared manure and its biochar influence on the spatial distribution of β-glucosidase, N-acetyl-glucosaminidase and phosphomonoesterase activities in Cr-contaminated soil using direct zymography. Maize was planted for 45 days in (a) soil mixed with manure, (b) soil mixed with manure-derived biochar and (c) soil without any addition. Soil pH decreased over 45 days, inducing an increase in acid soluble Cr. The concomitant decrease in β-glucosidase and N-acetyl-glucosaminidase activities explained the narrowing rhizosphere extent of enzyme activities by 13–44%, indicating that increased Cr bioavailability decreases microbial activities. A larger maize performance index and the greatest plant shoot/root ratio after biochar application suggested enhanced maize growth ( p < 0.05). In contrast, manure induced the narrowest extent of β-glucosidase and phosphomonoesterase activities due to the addition of labile organic compounds and nutrients following its application. Our study emphasizes the importance of pH on Cr bioavailability and enzyme activities and demonstrates that biochar application is more ideally suited for remediating Cr-contaminated soil.
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Qianwei Liang,Sittipranee Ploychompoo,Jingda Chen,Tingting Zhou,Hanjin Luo
Rational design strategy and facile synthesis method of photocatalysts with high efficiency and stability have been still a significant challenge for the removal of environmental contaminants. In this study, a three dimensional (3D) all-solid-state Z-scheme heterojunction photocatalytic system containing bismuth sulphide (Bi 2 S 3 ) and bismuth vanadate (BiVO 4 ) was constructed as Bi 2 S 3 -BiVO 4 graphene aerogel (SVGA) by a facile hydrothermal method. The potential application of as-synthesized SVGA was demonstrated to remove Cr(VI) and bisphenol A (BPA) simultaneously in aqueous media via the synergy of adsorption and photocatalysis under visible light irradiation. The removal rates of Cr(VI) and BPA both nearly reached 100% after adsorption for 40 min and photocatalysis for 120 min under visible light (λ > 420 nm), which was much better than the removal efficiency of individual Bi 2 S 3 and BiVO 4 , as well as Bi 2 S 3 graphene aerogel (SGA) and BiVO 4 graphene aerogel (VGA) samples. The rGO played an important role as photoinduced electron transfer mediator between Bi 2 S 3 and BiVO 4 , which promoted the photogenerated electrons transfer efficiency and enhanced photocatalytic ability of SVGA efficiently. The harmful Cr(VI) was conserved into hypotoxic Cr(III) and BPA was degraded into CO 2 and H 2 O after photocatalysis on SVGA, and the fabricated SVGA also presented favorable stability and satisfactory application effect in practical water samples, implied that such photocatalyst has a promising application for simultaneous removal of heavy metals and organics from aqueous environment.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Jingjing Xu,Chen Liu,Junfeng Niu,Yanlin Zhu,Biying Zang,Mengjuan Xie,Mindong Chen
LaFeO 3 /Bi 3 NbO 7 p-n heterojunction photocatalysts were prepared successfully through an in-situ growth method. The phase structure, optical property , morphology and microstructures of the obtained samples were studied by X-Ray diffractometer (XRD), Ultraviolet–visible absorption spectrum (UV–vis DRS), photoluminescence (PL) spectroscopy, transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM). The visible light responsive photocatalytic activity of as-obtained samples were investigated by the photo-reduction of Cr (Ⅵ). The effects of preparation conditions (proportion of BNO/LFO and temperature) on the activity were studied. Results showed that the as-obtained BNO-LFO-200-5 composite behaved the best photocatalytic activity (with rate constant of 0.0212 min −1 ) among all the obtained samples. The rate constant was about 42.4-times and 17.7-times as that of pristine BNO (0.0005 min −1 ) and LFO (0.0012 min −1 ), respectively. The enhanced photocatalytic property of the as-prepare LaFeO 3 /Bi 3 NbO 7 composites can be ascribed to the formation of p-n junction between BNO and LFO, which significantly increased the separation efficiency of photo-excited electron-holes.
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Baiyan Zeng,Wenbin Xu,Sher Bahadar Khan,Yanjie Wang,Jing Zhang,Jiakuan Yang,Xintai Su,Zhang Lin
A facile pyrolysis-quenching-reroasting process was developed to prepare a sludge-based biochar adsorbent, and its adsorption performance for Cr(VI) ions was investigated. The unquenched biochar (U-BC) and quenched biochar (Q-BC) were systematically compared and characterized. Fourier transform infrared spectroscopy (FTIR) results showed that more carbon and oxygen functional groups such as –COOH and –OH were formed on the surface of Q-BC. These functional groups could be used as active sites during the adsorption process and help to improve the adsorption performance of the material. The results of Brunauer-Emmett-Teller (BET) analysis showed that the specific surface area of U-BC biochar was 523.36 m 2 /g, while the specific surface area of Q-BC biochar after quenching treatment increased to 785.3 m 2 /g. The adsorption performance of Q-BC biochar was studied, and the effects of pH, contact time and temperature on the adsorption performance of the material were explored. The pseudo-second-order model and Langmuir isotherm model indicated that the removal of Cr(VI) by Q-BC biochar material was a chemical adsorption-based adsorption process. At a temperature of 298 K and a pH of 1, the maximum Cr(VI) adsorption capacity of the quenched Q-BC biochar is as high as 291.54 mg/g, which was much higher than the maximum adsorption capacity of U-BC biochar (91.46 mg/g). This pyrolysis-quenching-reroasting process to prepare modified biochar provides a new, economical and effective way for the preparation of high-performance adsorption materials from municipal sludge .
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Kaini Yang,Xiangyu Wang,Iseult Lynch,Zhiling Guo,Peng Zhang,Lisi Wu
Nano zero-valent iron (NZVI) is an ideal material for treating chromium (VI). However, the NZVI's low loading and corrosion susceptibility in acidic Cr-containing industrial wastewater is the most pressing issue. Therefore, it is necessary to explore a method to construct novel NZVI composites with high loading, corrosion resistance, and outstanding activity. In this study, green 2-mercaptobenzimidazole (MBI) was employed for the first time as a corrosion inhibitor for NZVI to form a protective coating through chemisorption, thus blocking the corrosion of NZVI by reaction medium. Meanwhile, a novel multiphase green crystallization-assisted pore formation freeze-drying method was constructed to synthesize UiO-66-NH 2 regulated 3D network porous polyacrylonitrile (PAN) cryogel film for stabilizing NZVI, which is intended to remove Cr(VI) effectively and without secondary contamination. The synthesized MBI-Fe 0 @MOF/PAN possessed prominent activity, corrosion resistance, and considerable NZVI loading (45.9 mg/g). The Cr(VI) removal could still reach 82.7 % after 6 cycles, and the level of total dissolved iron ions was lowered to 0.255 mg/L. MBI-Fe 0 @MOF/PAN for rapid removal of Cr(VI) may be ascribed to the synergistic reaction of rapid protonation of MBI and strong reduction of NZVI. This study constructed the MBI corrosion-resistant interface and 3D PAN cryogel film concepts not only to broaden the horizons of designing efficient NZVI catalytic materials but also to promote the development of treatment technologies for acidic Cr-containing industrial wastewater.
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Ruoning Chu,Xiaojie Guo,Yongjun Zhang,Xiaoyu Zhao,Xiantao Xiong,Xiujuan Zhang,Fengyi Zhang,Kun Zhang,Yaxin Wang
Water containing heavy metal ions can be extremely harmful to the environment and human body, thus the development of low-cost and high-efficient adsorbents has an exciting prospect. In this study, lignin/graphene aerogels modified with polydopamine and polyethyleneimine , respectively, were successfully prepared to remove Cr(VI) from aqueous waste. The physicochemical properties of graphene aerogels (GA), lignin/graphene aerogels (LGA), polydopamine-modified lignin/graphene aerogels (LGA@PDA), polyethyleneimine-modified lignin/graphene aerogels (LGA@PEI) were investigated using FT-IR, Raman spectroscopy , XRD , XPS , SEM-EDS, and BET analysis. The results demonstrate that adsorbents have a high specific surface area, an interconnected porous structure, and a large number of oxygen-containing groups, making them particularly favorable for heavy metal adsorption. The effects of GO/lignin ratio, surface modifiers, solution pH, contact time, initial concentration and temperature on the Cr(VI) removal were investigated and compared via batch experiments. Compared with GA (138.74 ± 3.93 mg/g), the adsorption capacity of LGA with GO/LA ratio 40:1 increased to 167.66 ± 4.75 mg/g. Furthermore, the maximum adsorption capacity of LGA@PEI and LGA@PDA rose up to 209.85 ± 3.25 mg/g and 240.39 ± 3.26 mg/mg, respectively. By simulating the experimental data with different kinetic models and isotherm models, the adsorption processes of different lignin-derived aerogels were further explored under various conditions. All types of aerogels fit well with the pseudo-second-order model and Langmuir model. In addition, the XPS results confirm that the chemical reduction of Cr(VI) to Cr(III) also plays a role in the removal of Cr(VI). The results demonstrated that the removal effect of lignin-derived aerogels on Cr(VI) was greatly improved through the multi-functionalized surface modification of LGA with PDA and PEI. Furthermore, the removal efficiency of LGA@PDA and LGA@PEI for Cr(VI) remained stable after repeated regeneration. Therefore, the results of this study indicate that LGA@PDA and LGA@PEI are promising Cr(VI) adsorbents for practical applications in wastewater treatment.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Dengjia Shen,Hongyang Ma,Madani Khan,Benjamin S. Hsiao
Both plastic (e.g., polyvinyl chloride (PVC)) solid waste and bacteria/heavy metal ions-containing wastewater pose a severe threat to the environment, which must be addressed simultaneously by developing highly efficient and sustainable strategies. Novel cationic PVC nanofibrous membranes with high filtration and adsorption capability were fabricated by electrospinning and surface grafting, and then employed for the removal of bacteria (e.g., E. coli ) and hexavalent chromium (Cr (VI)) ions for wastewater treatment. A cationic pendant, methylimidazolium, was covalently anchored on the surface of PVC nanofibers and verified using FTIR-ATR, NMR, and SEM measurements. As a result, the optimized cationic PVC nanofibrous membrane (PVC-MIM) exhibited remarkable filtration efficiency for E. coli (LRV ≥ 6.1) from contaminated water, and a maximum adsorption capacity of 285.7 mg/g against Cr (VI). Kinetics, isotherms, and thermodynamics of the nanofibrous PVC-MIM membrane in the adsorption process were extensively investigated. The separation mechanism was proposed based on size exclusion, charged interactions, and hydrogen bonding/coordination between the membrane and the targets. Used sewer pipes and electric cables were employed as raw materials to fabricate modified nanofibrous membranes (0.9 g) to then manufacture of a spiral-wound PVC-MIM nanofibrous membrane cartridge. The resulting system exhibited a retention rate as high as 100 % when 24 L of simulated tanning wastewater containing concentrated suspended solids, oil, ammonia–nitrogen, chloride, and other pollutants were tested for a dynamic adsorption process. Furthermore, the nanofibrous membrane cartridge could be recycled ten times while the regeneration ratio remained as high as 91.0 %.
✓ 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）