DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 14
·4570-4577
·
IF 4.174
Xing Xin,Na Hu,Yuanyuan Ma,Yali Wang,Lin Hou,Heng Zhang,Zhangang Han
It is crucial to find a convenient and sensitive method for quantitative determination of heavy metal chromium(VI) ions. Developing crystalline materials coupled with polyoxometalates as an electrochemical sensor is a promising approach to address the above issues. Here we reported two reductive polyoxometalate-based crystalline compounds with the formula of (H2bpp)2[Na4Fe(H2O)7][Fe(P4Mo6O31H6)2]·2H2O (1) and (H2bpp)6(bpp)2[Fe(P4Mo6O31H8)2]2·13H2O (2) (bpp = 1,3-bi(4-pyridyl)propane). Structural analysis indicated that both two compounds were composed of inorganic polyanionic clusters and organic protonated bpp cations. The difference lies in the arrangement mode of the inorganic moiety: crystal 1 shows a unique three-dimensional (3-D) inorganic porous skeleton, while crystal 2 consists of isolated 0-D polyanionic clusters. When used as electrochemical sensors in the determination of trace Cr(VI), crystal 1 shows a broad linearity range (2–2610 μM) with a low limit of detection (LOD) of 0.174 μM (9 ppb), which is superior to that of compound 2 (a LOD of 0.33 μM) and meets the standard of Cr(VI) in drinking water set by the WHO (less than 0.962 μM or 50 ppb). Importantly, crystal 1 showed benign selectivity to Cr(VI) in the presence of various heavy metal ions and good reproducibility in a real water sample, which prove its strong anti-interference ability. In addition, experimental results showed that the spatial arrangement of polyanionic clusters could affect the final electrochemical behavior of crystalline materials. This work provides some insights into the design of cost-effective POM-based electrochemical sensors at the molecular level.
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高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 39
·期 5
·1257-1267
·
IF 3.146
Cheng Liang,Zhang Li,Wang Hongxia,Song Fangxiang
Mesoporous silica (MS) and graphene oxide (GO) are good absorbents. Combining them not only prevents GO agglomeration but increases the number of MS active sites. In addition, their composites can preferentially adsorb specific pollutants after modification. In this work, amino-modified GO/MS materials were prepared by post-grafting to remove Congo red (CR) and Cr(VI) in solution. Characterization methods, such as X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Zeta potential, and N 2 adsorption/desorption, were adopted. The prepared GO/MS@HBP has a porous structure with a specific surface area of 49.32 m 2 ·g −1 . The effect of initial concentration, pH, adsorption time, temperature and other ions was determined on the adsorption amount. Relying on this, the GO/MS@HBP maximum capacity for Cr(VI) and CR adsorption are 93.73±2.3% and 257.69+1.5% mg·g −1 , respectively. Pseudo-second-order kinetic and Langmuir isotherms are more suitable to describe the adsorption process, indicating that chemical adsorption plays a major role in the entire adsorption process. Thermodynamics showed that the enthalpy (H) of materials adsorbing two pollutants was positive and that the Gibbs free energy (G) was negative, suggesting that Cr(VI) and CR adsorption on GO/MS@HBP was spontaneously endothermic. GO/MS@HBP could simultaneously remove CR and Cr(VI) in solution, and be an effective adsorbent for removing harmful substances.
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JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Yunhao Xie,Lun Lu,Baoliang Chen
The demands for genuine remediation of heavy metal contaminated soil have triggered extensive studies in the soil washing method. However, numerous soil washing methods show poor sustainability for target soil, due to the tremendous cost, hidden secondary pollution and severe soil deterioration. Here, an asymmetrical alternating current electrochemically-mediated remediation platform (ACRP) is developed by fabricating an amidoxime-functionalized electrode (Ami-electrode). The real soil contaminated with 1200 mg/kg Cr(VI) is remediated efficiently to less than safety level (30 mg/kg), meanwhile no exorbitant soil nutrient loss is observed and no secondary pollution occurs. Furthermore, the consumption of washing effluents for the ACRP method is 24 times lower than the traditional washing method. Ami-electrode with asymmetrical alternating current promote the electrocatalytic efficiency by inhibiting the Coulomb repulsion between Cr(VI) species and cathode. With the aid of Ami-electrode and positive bias, Cr(VI) species in effluents are adsorbed on chelating site. By subsequent negative bias, Cr element is reduced and recycled in the less hazardous form of amorphous Cr(III) hydroxide, and effluents are regenerate concurrently in a cyclic system. Durability experiment and cost calculation verify the exceptional sustainability and feasibility for remediation practices. This work provides a sustainable remediation method for Cr(VI)-contaminated soil, and then paves the way to develop electrochemically soil remediation platform for practical applications.
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PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2022
·
IF 7.926
Xiaodong Wang,Yongxun Dai,Chen Tian,Huize Zhang,Xiwen Li,Wenlong Liu,Weibing Li,Shaoping Kuang,Hongtao Tong
Photocatalysts can be effectively recovered and reused by compounding with magnetic nanostructures. How to further improve the photocatalytic performance of magnetic heterojunction photocatalysts remains a great challenge. In this work, g-C 3 N 4 /ZnFe 2 O 4 (CN/ZFO) magnetic heterojunction photocatalyst was first prepared and then modified with ultrathin MoS 2 (CN/ZFO/MoS 2 ) by simple ball-milling method. Then the photocatalytic removal of Cr(Ⅵ) performance of the prepared series photocatalysts was evaluated in detail. The optimum CN/ZFO/MoS 2 can achieve 99.3% Cr(Ⅵ) removal under 200-min simulated sunlight illumination, which is much higher than CN/ZFO (54.0%). The enhanced photocatalytic performance benefits from the modification of MoS 2 , which improves the light absorption performance, facilitates the transfer of photogenerated carriers , increases the concentration of photogenerated carriers and promotes the effective separation of photogenerated carriers. This work provides a theoretical basis for further preparation of magnetic recyclable photocatalysts with high photocatalytic performance.
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高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Zhuang Cao,Lixian Zhao,Yabing Sun,Jingwei Feng
The pollution of water by antibiotics and heavy metals has attracted more and more attention of scholars. Enrofloxacin (EFA) is a typical third generation fluoroquinolone antibiotic , which is widely used in human activities. Hexavalent chromium has been a great threat to human health and ecosystem due to its high mobility, toxicity and carcinogenicity . In this study, EFA-Cr(VI) mixed solution was used as a typical antibiotic - heavy metal simulated wastewater. We used a uniaxial wet-wall dielectric barrier discharge plasma reactor to simultaneously transform Cr(VI) and remove EFA for the first time, and its universality in the degradation of heavy metal pollution caused by other antibiotics was explored, providing a new solution for the simultaneous rapid and efficient treatment of antibiotic and heavy metal-contaminated wastewater. Within 18 min, the presence of hexavalent chromium greatly increased the degradation rate of EFA from 65.1% to 94.6%. The removal rate of hexavalent chromium was increased from 63.9% to 98.3% by the presence of EFA. The effects of initial pollutant concentration , input voltage, gas velocity , liquid circulation velocity, pH, organic matter and heavy metal ions were also investigated in this study. Free radical scavenging experiments showed that •O 2 , - •OH and 1 O played an important role in the detoxification of EFA. The Cr(VI) conversion experiments showed that the EFA degradation intermediates, hydrogen peroxide and •H were the main factors of Cr(VI) reduction in the EFA co-degradation system. The degradation pathway was inferred based on the measured EFA intermediates. The developmental toxicity of EFA and its degradation products was quantitatively studied. The results showed that the toxicity of EFA wastewater was reduced after DBD treatment.
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Nanoscale Research Letters
·
2021
·Vol. 16
·期 1
·1-12
·
IF 4.703
Ma Xiao Li,Fei Guang Tao,Xu Shao Hui
Abstract In this study, polyaniline (PANI) is prepared by means of chemical oxidization polymerization and directly loaded on the modified fiber ball (m-FB) to obtain macroscale polyaniline/modified fiber ball (PANI/m-FB) composite, and then its removal ability of Cr(VI) is investigated. The effects of different parameters such as contact time, pH value and initial concentration on Cr(VI) removal efficiency are discussed. The experimental results illustrate that the favorable pH value is 5.0 and the maximum removal capacity is measured to be 293.13 mg g −1 . Besides, PANI/m-FB composites can be regenerated and reused after being treated with strong acid. The kinetic study indicates that the adsorption procedure is mainly controlled by chemical adsorption. More importantly, the macroscale of composites can avoid secondary pollution efficiently. Benefiting from the low cost, easy preparation in large scale, environmentally friendly, excellent recycling performance as well as high removal ability, PANI/m-FB composites exhibit a potential possibility to remove Cr(VI) from industrial waste water. Graphic Abstract The polyaniline (PANI) was coated on modified fiber ball (m-FB) to remove Cr(VI) in waste water, and this kind of PANI/m-FB composites can avoid secondary pollution efficiently due to its macrostructure. Furthermore, the removal capacity can reach to 291.13 mg/g and can be multiple reused.
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Desalination and Water Treatment
·
2024
·
IF 1
Shaojun Li,Xiaoxuan Fan,Zhongping Chen,Lei Bai
A nanosized zeolitic imidazolate framework-67 (ZIF-67) was employed for the adsorption of Cr(VI) under a neutral solution. It was discovered that the ZIF-67 demonstrated a high adsorption of Cr(VI) for the first (43.1 mg·g –1 ) and second run (40.2 mg·g –1 ). However, a self-sacrifice process of ZIF-67 was evidenced, possibly due to the oxidability of Cr(VI) and pH change, which resulted in a dramatically decrease of adsorption ability in the third run (16.6 mg·g –1 ). The adsorption process and its kinetics fitted the Langmuir model and pseudo-second-order rate equation and a multiple adsorption process was suggested.
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CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Xueyan Li,Suya Li,Chong Peng,Yuanfei Wang,Yun Li,Shuyi Yang,E. Tao
To avoid the environmental detriment caused by Cr(VI) waste, this study constructs a dual cross-linking network structure using sodium alginate (SA) and polyvinyl alcohol (PVA). Chitosan (CS) is further introduced through electrostatic attraction and hydrogen bonding and SA/PVA/CS (SPC) composite with porous structure is successfully prepared for the removal of Cr(VI) from wastewater. Batch adsorption experiments show that SPC has excellent adsorption capacity and practical usability with a broad pH applicability range. Under optimal adsorption conditions (pH = 2, t = 150 min, T = 35 °C, m/ V = 2 g/L, C 0 = 10 mg/L), the Cr(VI) removal rate of SPC achieves 89.2 %. Adsorption kinetics and isotherm models indicate that the adsorption process is primarily multi-layer and chemical adsorption. Additionally, FT-IR and XPS reveal that the adsorption mechanism of SPC for Cr(VI) involves a synergy of electrostatic attraction, reduction, ion exchange and complexation. Density functional theory (DFT) simulations also confirm the dominant role of CS in the Cr(VI) adsorption. In summary, SPC shows great potential for Cr(VI) wastewater treatment.
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DALTON TRANSACTIONS
·
2017
·Vol. 46
·期 47
·16525-16531
·
IF 4.029
Fu-hua Wei,Ding Chen,Zhao Liang,Shuai-qi Zhao,Yun Luo
Fe-Based metal–organic frameworks (Fe-MOFs) were prepared with trimesic acid and FeSO4·7H2O via a microwave-assisted ball milling approach. The structure and thermal stability of the as-prepared Fe-MOFs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). When used to degrade 20 mg L−1 hexavalent chromium in aqueous solution, the Fe-MOFs were found to completely reduce a 100 mL solution within 120 min under natural light and a 400 mL solution within 90 min under Xe lamp irradiation. Under natural sunlight, 98% of the Cr(VI) was removed from a 40 mL solution after 40 min.
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Toxics
·
2025
·Vol. 13
·期 6
·458
·
IF 4.1
Hang Liu,Runlin Yao,Mingling Yu,Zongda Ye,Yingrui Lu,Xiaolong Yu,Jin Tang,Jianteng Sun
Hexavalent chromium (Cr(VI)) is of significant interest in the environmental field due to its high toxicity. Biochar is commonly used as an adsorbent for Cr(VI) removal from wastewater. However, its lower removal efficiency remains a persistent challenge. This study develops an iron-modified rice straw biochar through a simple precipitation and pyrolysis method and applies it for Cr(VI) removal in wastewater, which could convert waste into treasure and improve the adsorption performance of adsorbent. In the adsorption experiments, the results revealed that the adsorption efficiency of Cr(VI) reached 95.54% within 480 min (conditions: adsorbent dosage 2.67 g/L, pH 2.5, temperature 25 ± 2 °C). The Langmuir isotherm model was more suitable to describe the adsorption behavior of Cr(VI) by Fe-BC, and the fitted adsorption capacity achieved 10.03 mg/g. The experimental process was better described by the pseudo-second-order kinetic model, indicating that the adsorption process chemical adsorption was the rate-limiting step. The thermodynamic experiments revealed that the adsorption process of Cr(VI) by Fe-BC was spontaneous and endothermic. Column experiments demonstrated that a lower flow speed was beneficial to adsorption performance. Mechanistic studies highlighted the synergistic roles of electrostatic attraction, ion exchange, and reduction in Cr(VI) removal. These findings provide novel perspectives and innovative approaches for the development and application of adsorbents.
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Qianyu Wang,Changchang Ma,Dandan Liu,Shushan Song,Ziheng Song,Weijie Zhang,Huarui Han,Jiasheng Zhu,Kai Wei,Sheng Feng
Confining nano zero-valent iron (nZVI) into porous materials could prevent its aggregation and passivation. In this study, we confined nZVI into the cavity of zeolitic imidazolate framework-8 (ZIF-8) via sequential pre-adsorption ferric ion (Fe(III)) and NaBH 4 reduction processes. The optimized Cr(VI) removal rate of ZIF-8 confined nZVI (nZVI@ZIF-8) reached 1.2 × 10 −1 min −1 , 9.2- and 37.5-fold that of nZVI and ZIF-8, respectively. Interestingly, the removal rate constants of nZVI@ZIF-8 toward Cr(VI) still reached 9.6 × 10 −2 min −1 and 6.7 × 10 −2 min −1 with initial pH of 7.0 and 9.0, respectively, 13.0 (7.4 ×10 −4 min −1 ) and 23.9 times that of nZVI. More importantly, channels confinement significantly improved the reactive lifetime of nZVI for Cr(VI) removal. The electro-donating -NH 2 provided positive charge sites for CrO 4 2- or HCrO 4 - adsorption. Subsequently, the difference of Fermi level between nZVI and ZIF-8 drove electrons transfer from nZVI to ZIF-8 for surface Cr(VI) reduction. This study provides an avenue to enhance the performance of nZVI toward heavy metal ions removal by coupling surface adsorption and nano confinement.
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高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Ruiqing Sun,Jing Yuan,Tong Zhou,Yujuan Xie,Qilong Zhan,Shiyi Lu,Haoran Fan,Yangyang Wen,Hongyan Li
Cr(VI), a highly toxic and carcinogenic contaminant, presents significant risks to ecological and human health due to its pervasive presence in food and environmental systems. Even minimal exposure can induce oxidative stress and genotoxicity, underscoring the urgent need for rapid, sensitive, and field-deployable analytical methods. In this study, we developed a ratiometric fluorescence probe based on a blue-emitting metal-organic framework (MOF) as the reference signal and a red-emitting CdTe quantum dot (QDs) as the responsive element. Upon Cr(VI) exposure, red fluorescence is quenched through inner filter effect (IFE) and electrostatic interaction (EI), while blue fluorescence remains unaltered, resulting in a visible color change from pink to blue. To achieve precise quantification, the ratiometric system was integrated with three representative ML algorithms—Random Forest (RF), Support Vector Regression (SVR), and BP Neural Network (BPNN). Smartphone-captured fluorescence images were processed by extracting RGB values to train and validate the ML models. Among them, the RF algorithm demonstrated superior performance, achieving an R 2 value of 0.9942, root mean square error of prediction of 3.5842, mean absolute error of prediction of 2.1893, and 93.31 % prediction accuracy. The proposed method achieved satisfactory recovery rates of 98.81–134.00 % and relative standard deviations below 4.32 % in real food and environmental samples. This study presents an intelligent, dual-mode strategy integrating ratiometric fluorescence sensing with machine learning for trace Cr(VI) detection. The approach offers high sensitivity, accuracy, and visual recognition, providing a generalizable platform for automated, on-site, and visualized analysis in complex food and environmental matrices.
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高影响因子
危险品化学品经营许可证（带存储）