WATER AIR AND SOIL POLLUTION
·
2022
·Vol. 233
·期 12
·1-14
·
IF 2.984
Li Weiquan,Li Mingxi,Yin Weizhao,Zhang Weinan,Zhong Jiawei,Li Ping,Deng Hong,Wu Jinhua
The removal of Cr(VI) from groundwater by zero-valent iron (Fe 0 ) and microorganisms under different nutrients and electron-accepting conditions was investigated using continuously-flowed column reactors with an abiotic Fe 0 column as the control. Both abiotic and biotic Fe 0 columns were operated at low and relatively high concentrations of organic substrates (sodium acetate and humic acid) and electron acceptors (nitrate and sulfate). Sodium acetate and humic acid were found to be effective substrates for the biotic Fe 0 system to remove Cr(VI) since microorganisms were able to gain extra reducing capacity from two nutrients and simultaneously avoid the passivation effect of humic acid on Fe 0 by metabolizing it. For nitrate and sulfate, varied influences were observed in the biotic Fe 0 system. The former showed apparent inhibition on Cr(VI) removal as it competed with Cr(VI) for electrons, and the inhibition became more severe while nitrate concentrations increased. Differently, highly reactive minerals such as green rusts and iron sulfide could be generated on the biotic Fe 0 surface under sulfate-reducing condition. They significantly enhanced Cr(VI) removal by providing more adsorptive and reductive sites. Overall, though the biotic Fe 0 column exhibited a longer life-span and higher Cr(VI) removal capacity than the abiotic Fe 0 column, the effects of organic substrates and electron acceptors should still be taken into account when applying biotic Fe 0 systems for Cr(VI)-contaminated groundwater remediation.
✓ 已验证
产品关联
DOI
高影响因子
Electrocatalysis
·
2022
·Vol. 14
·期 1
·78-87
·
IF 2.933
Gu Ying-ying,Xiang Ding-tao,Cai Ke,Wang Yuan-hao,Mei Yong,Han Jun,Pan Hongzhi
The rapid determination of Cr(VI) in workplace air can provide technical support for daily monitoring of occupational hazard factors in enterprises. In this paper, a bismuth film/carboxylated multi-walled carbon nanotube modified glassy carbon electrode (Bi/CMWCNTs/GCE) electrochemical sensor had been used to establish a new method for detection of Cr(VI) in workplace air. Carboxylated multicycle carbon nanotubes (CMWCNTs) were modified onto glassy carbon electrode (GCE), and bismuth (Bi) film was precoated on the modified electrode by electrodeposition. The morphology and electrochemical properties of Bi/CMWCNTs modified electrodes were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV), respectively. The results showed that the formation of stable bismuth films and sensor’s high sensitivity were due to CMWCNTs. The differential pulse stripping voltammetry (DPSV) response of Cr(VI) at Bi/CMWCNTs modified electrode outcomes with a low detection limit of 0.18 μg/L and wider linear 0.50 ~ 25.0 μg/L. In comparison to standard spectrophotometry, the newly designed electrochemical sensor had exhibited more sensitive, convenient, and environmentally friendly, which was satisfactory in analytical application to real air samples. Therefore, the Bi/CMWCNTs/GCE electrochemical sensor has the potential applications in the rapid detection of Cr(VI) in workplace air. Graphical abstract
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Wen-bo Tan,Dan Luo,Wei Song,Yan-yan Lu,Nuo Cheng,Jia-bin Zhang,Ting Huang,Yong Wang
Highly efficiently removing hazardous heavy metal ions from water is very important from a viewpoint of maintaining the sustainable development of ecological environment. In this work, a novel adsorbent based on the cellulose acetate (CA) was developed, which was fabricated through the blend electrospinning of CA and titanium dioxide (TiO 2 ) nanoparticles, surface modification by polydopamine (PDA) and then grafted by polyethyleneimine (PEI). The composite CA/TiO 2 electrospun fibers exhibit the porous structure, while the surface modification by PDA-assisted PEI grafting has no apparent effect on morphology of the electrospun fibers. The CA/TiO 2 @PDA@PEI composite fibers show the large number of amine groups, and the surface of the fibers can be positively charged in the acidic solution. Adsorption measurements show that the fibrous membrane samples exhibit excellent adsorption ability toward Cr(VI), and the maximum adsorption capacity is as high as 357.1 mg g −1 at solution pH value of 2, solution temperature of 25 °C. Specifically, about 72.1 % Cr(VI) can be directly reduced to harmless Cr(III) during the adsorption measurement, which is much higher than those of the almost adsorbents reported in literatures. The excellent adsorption/reduction ability endows the fibrous membranes with great potential application in removing highly hazardous Cr(VI) from wastewater.
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Chenxi Lu,Yuanzhuo Zhou,Liangzhi Li,Hongwei Chen,Lishi Yan
Catalytic production of 5-hydroxymethylfurfural (5-HMF) from glucose is a promising routine for generation of varied value-added chemicals. Herein, Mixed-Metal metal–organic frameworks (MOFs)–Fe/MIL-101(Cr) and MIL-101(Cr, Fe) obtained from post-synthesis modification and one-pot synthesis approach respectively were applied for catalytic converting glucose to 5-HMF. The synthesized Mixed-Metal MOFs were characterized by PXRD, SEM, N 2 adsorption–desorption analysis, TGA, XPS and NH 3 -TPD. Cr-and Fe-containing Mixed-Metal MOFs Fe/MIL-101(Cr) and MIL-101(Cr, Fe) presented synergistic effect with enhanced catalytic ability for glucose transformation to 5-HMF compared with typical single-metal MOFs and sulfonic acid-functionalized MOFs. Moreover, these two Mixed-Metal MOFs also presented better thermal stability than single-metal MOFs like MIL-101(Cr). Fe/MIL-101(Cr) was found to possess higher catalytic performance than MIL-101(Cr, Fe). 55.8 % 5-HMF yield was obtained with Fe/MIL-101(Cr) at 170 °C for 2 h in DMSO/water system. In addition, Fe/MIL-101(Cr) demonstrated desired recyclability for five times without incredible loss in its activity. This study provides a Mixed-Metal strategy on MOFs for improving catalytic efficiency of glucose conversion to 5-HMF.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Taotao Qiang,Boqiang Qiu,Lu Chen,Longfang Ren
In this work, a novel adsorbent for the removal of hexavalent chromium (Cr(VI)) in aqueous solution was successfully prepared by altering the 2D Ti 3 C 2 /chitosan composite with disodium ethylenediaminetetraacetate (EDTA·2Na) agent. The successful surface loading of chitosan on Ti 3 C 2 was demonstrated by various characterization methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The adsorption of Cr(VI) by Ti 3 C 2 -based composite under various circumstances was evaluated using batch adsorption experiments. The adsorption performance of the optimal sample for Cr(VI) was investigated in detail through different influencing factors, and the adsorption process was analyzed by adsorption kinetics and isotherm model. In addition, XPS analysis of adsorbents before and after adsorption showed that some Cr(VI) was reduced to Cr(III) during the whole process, which was conducive to reducing the biological toxicity of Cr(VI). The mechanism analysis showed that the adsorption was mainly electrostatic physical adsorption, supplemented by chemical reduction adsorption. Finally, through the regeneration cycle experiment, it was found that the adsorption rate of Cr(VI) remained above 80% after six repeated adsorptions, indicating that the composite material had good stability and might have certain practical application value in the treatment of Cr(VI)-containing wastewater.
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Hongwei Wang,Fang Wu,Zhiheng Wang,Yang Wang,Shufang Zhang,Haijun Luo,Zhiqin Zheng,Liang Fang
Chromium (VI) removal is crucial to the safety of water resources, but there is still a lack of effective and fast dislodge methods, especially the on-site rapid remediation and emergency removal technology . Herein, the monolayer (ML) Ti 3 C 2 T x nanosheets (NSs) were prepared to remove Cr (VI) from water. The solution sample of the two-dimensional (2D) Ti 3 C 2 T x NSs demonstrate ultrafast adsorption kinetics (the concentration decreasing from 300 to 3 mg L −1 in 10 min) and impressively high capacity (1483 mg g −1 ), which is several times higher than that of the most reported Cr (VI) adsorption by Ti 3 C 2 T x . The analysis of the adsorption kinetics and isotherm models indicates that the adsorption reaction is endothermic, with physical and chemical adsorption coexisting (mainly monolayer chemical adsorption). The joint study of the experimental analysis and theoretical calculation based on the density functional theory (DFT) demonstrates that the extraordinary removal performance of Cr (VI) is due to the synergetic effect of reduction reaction removal and electrostatic adsorption. It is found that the Cr (VI) is mainly reduced by the OH- terminals on Ti 3 C 2 , and the detoxified Cr (III) is anchored on the surface of Ti 3 C 2 T x through complexation reaction with O terminal. The advantages of ultrafast adsorption kinetics and extra-high adsorption capacity of the single-layered Ti 3 C 2 T x for Cr (VI) removal make it a remarkable candidate for rapid and urgent removal of Cr (VI) wastewater.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Yuhan Zhu,Jia Wei,Jun Li
Biochar is a well-known material for pollutant removal owing to its low cost and rich surface functionality. A kind of highly active substance, called environmentally persistent free radicals (EPFRs), can be produced in the preparation process of biochar, playing an important role in the removal of pollutants. In this study, sludge-derived biochars (SBC 120 and SBC 270 ) were prepared by the hydrothermal carbonization under two temperatures (120 °C and 270 °C) to investigate their removal abilities of Cr(VI). The maximum removal amounts of Cr(VI) by SBC 120 and SBC 270 were 16.58 and 22.93 mg·g −1 , respectively. It was further revealed that the appearance of Cr(III), as a result of EPFRs on sludge-derived biochar (SBC) transferred electrons to Cr(VI) in neutral solutions. That is to say, oxygen-centered (O-centered) EPFRs on SBC 120 and carbon-centered (C-centered) EPFRs on SBC 270 all could be used as electron donors to Cr(VI) to make it become Cr(III). This study not only provides a theoretical basis for the mechanism of pollutants removal by sludge-derived biochar but also offers a new perspective on the direct effect of EPFRs on pollutants.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2022
·
IF 3.475
Mingxing Chen,Qinming Guo,Jinping Cui,Weiyang Lv,Yuyuan Yao
Developing high-performance adsorbent for hexavalent chromium (Cr(VI)) elimination presents an enticing prospect in environmental remediation. Herein, three-dimensional flowerlike nanospheres composed of molybdenum disulphide and polypyrrole (MoS2@PPy) were successfully prepared via a one-pot hydrothermal and subsequent carbothermal reduction process for the removal of Cr(VI). The effects of pH, adsorbent dosage, co-existing ions, initial Cr(VI) concentration and temperature were investigated systematically by batch experiments. Benefiting from the incorporation of MoS2, the obtained MoS2@PPy composites showed a dramatic increase of specific surface area (149.82 m2·g−1) and adsorption capacity (230.97 mg·g−1) when compared with the pure PPy nanoparticles. Based on the thermodynamics study and X-ray photoelectron spectroscopy analyses, the removal process of Cr(VI) was proved to be exothermic and spontaneous, and accessible under-coordinated Mo(IV) and pyrrolic N groups coupled with redox reactions were conducive to the efficient removal of Cr(VI). Attractively, the MoS2@PPy acted as the electron donor could also activate peroxymonosulphate for the efficient degradation of organic contaminants. These results suggested that the MoS2@PPy was promising in Cr(VI) elimination and other kinds of organic pollutants removal in wastewater.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2022
·
IF 4.644
Meng Tan,Qiaoyuan Gao,Yangjie Fu,Youran Xu,Derek Hao,Bing-Jie Ni,Qi Wang
In this study, a new coordination polymer of Fe-2-methylimidazole (Fe-2MI) was successfully loaded onto F-doped tin oxide (FTO) via a one-pot solvothermal method, using Fe(NO 3 ) 3 and 2MI as raw materials. For X-ray diffraction patterns (XRD) and scanning electron microscope (SEM) analysis, it can be deduced that Fe-2MI assembles were evenly dispersed on the surface of FTO, and were partially encapsulated by tiny FeOOH particles. The as-prepared Fe-2MI film electrode was used as photoanode with titanium sheet (Ti) as the cathode. Simultaneous photoelectrocatalytic (PEC) removal of phenol and Cr(VI) can be effortlessly accomplished under noticeable light illumination. Meanwhile, the impact of initial Fe state was also investigated. Fe-2MI prepared with Fe(III) behaved better PEC performance than that with Fe(II). Furthermore, the Fe-2MI photoanodes were optimized by adjusting the initial concentration of Fe(III) and 2MI precursors. Besides, the application conditions were optimized at acidic pHs and 2.5 V bias voltage . Cr(VI) can be completely reduced with 80% removal of phenol after 5 h PEC reaction. After 5 successive cyclic runs, stable photocatalytic performance can still be observed. Therefore, Fe-2MI coordination polymer can be a promising candidate for preparing visible-light-active photoanode in the application of environmental remediation.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yuting Long,Hong Li,Wenbo Wang,Xinxin Yang,Zirui Liu
Ultrasensitive detection of highly toxic Cr(VI) is of paramount importance as trace amount of Cr(VI) will result in inevitable deterioration to human health and the environment. In this work, a novel methimazole-functionalized SERS optical fiber probe was used for the first time for Cr(VI) determination with ultrahigh sensitivity. A special functionalization process of methimazole was designed after successful fabrication of silver coated fiber probe via a SnCl 2 -sensitized solvothermal method. Dual functional methimazole guaranteed ultrahigh sensitivity and good stability of the SERS fiber probe for Cr(VI) detection. On one hand, methimazole functions as a Raman reporter which exhibits SERS peak intensity decline in the presence of Cr(VI). On the other hand, methimazole acts as an oxidation inhibitor via coordinating with silver atoms through the lone pair of nitrogen and sulfur atoms. The optimized SERS fiber probe not only presents good stability and excellent reproducibility, but also exhibits ultrahigh sensitivity (10 −11 M) which exceeds SERS or other techniques for Cr(VI) determination reported so far.
✓ 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
Yan Yi,Xiangyu Wang,Yaxian Zhang,Jun Ma,Ping Ning
The aquatic plant Egeria najas based biochar was innovatively constructed by modifying it with Fe 2 (SO 4 ) 3 (Fe 2 (SO 4 ) 3 @EN-BC) for Cr(VI) removal. The characterizations of Fe 2 (SO 4 ) 3 @EN-BC confirmed that Fe 2 (SO 4 ) 3 was attached to biochar in form of Fe 2 O 3 after hydrolysis and calcination under high temperature. The results showed that Fe 2 (SO 4 ) 3 @EN-BC had a high removal efficiency of Cr(VI) with approaching 99.88%, which was about 7 times higher compared to unmodified biochar (EN-BC). Batch experiments of Cr(VI) removal included initial concentration, reaction temperature, solution pH and kinetics were conducted. The adsorption kinetics could be more accurately explained using pseudo-second order kinetics model , indicating the chemical adsorption controlled the reaction process. According to the Langmuir model, the maximum adsorption capacities for Cr(VI) were 138.79, 159.36 and 190.91 mg/g at 298, 313 and 333 K, respectively. Moreover, based on FTIR and XPS results, the Fe 2 (SO 4 ) 3 @EN-BC surface was loaded with many functional groups conducive to Cr(VI) adsorption. The main removal mechanisms of Cr(VI) by Fe 2 (SO 4 ) 3 @EN-BC included adsorption and reduction, and the percentage of Cr(VI) removed by adsorption and reduction were 19.1% and 80.9%, respectively.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Feifei Zhang,Wei Shi,Shangyi Guan,Yugen Xu,Heng Yang,Hao Chen,Jie Xing,Hong Liu,Qiang Chen
Bi 4 Ti 3 O 12 (BIT), a typical layered-structure ferroelectric with a high Curie temperature ( T C ), is a promising material for high-temperature sensors. Herein, W/Cr co-substitution at the B-site of BIT ceramics (BITWC100 x ) is carried out to investigate the phase structure, domain structure, and electrical properties. The W/Cr addition apparently reduces the concentration of oxygen vacancies , effectively improving the ferroelectric and piezoelectric properties as well as the resistivity of the BIT ceramics. The BITWC2 ceramic exhibits a high piezoelectric coefficient ( d 33 = 31.1 pC/N), a moderate T C (651 °C), a large remnant polarization ( P r = 12.2 μC cm −1 ), and a prominent direct current resistivity (5.49 ×10 6 Ω·cm at 500 °C). Moreover, the BITWC2 ceramic possesses a large d 33 of 26.6 pC/N at an annealing temperature of 600 °C, indicating the excellent thermal stability of the piezoelectric coefficient. Overall, the BITWC100 x ceramics can be used in piezoelectric devices at temperatures up to 500 °C.
✓ 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）