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.
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Xingrui Tong,Jinling Bao,Danfeng Chang,Dapeng Wang,Haibo Chang,Liquan Jing
Designing an efficient hole–electron separation method is essential to improving the photocatalytic efficiency of photocatalysts. Herein, we constructed a 3D MoS2/MgIn2S4 S-scheme heterojunction material using a solvothermal method. The built-in electric field formed by the interaction between MoS2 and MgIn2S4 promoted the separation of electrons and holes, significantly improving the photocatalytic activity of 3D MoS2/MgIn2S4. The 3% MoS2/MgIn2S4 composite photocatalyst successfully achieved a 100% reduction of Cr(VI) within 90 min and demonstrated good hydrogen production efficiency without using a sacrificial agent. Theoretical calculations confirmed the formation of S-scheme heterojunctions. Malondialdehyde and dehydrogenase tests showed that the Cr(VI) solution after reduction was not harmful to plant growth. Furthermore, we systematically investigated the effects of different Cr(VI) concentrations, catalyst dosages, ions, pH values, and organic acids on photocatalytic efficiency. The design of the S-scheme heterojunction photocatalysts provided a promising strategy for the photoreduction of Cr(VI).
✓ 已验证
DOI
高影响因子
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.
✓ 已验证
DOI
高影响因子
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.
✓ 已验证
DOI
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.
✓ 已验证
DOI
高影响因子
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.
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Chuanqi Tang,Yiming Zhang,Jiangang Han,Ziqi Tian,Liang Chen,Jianqiang Chen
Supported carbon quantum dots (CQDs), used as fluorescent sensors for the detection of metal ions , have rarely been used to remove heavy metals from water. Nitrogen-doped CQDs immobilized in hydrophilic silica hydrogels exhibited a more superior sensitivity and selectivity for the detection of Re(VII) and Cr(VI) than other metal ions, including Fe(III), Fe(II), Zn(II), Cu(II) and Mn(II). For the first time, low limits of detection (LOD) of 2.3 μM for Re(VII) detection and 65 nM for Cr(VI) detection were reported by a facile method. Based on the high selectivity of fluorescent silica hydrogels for Re(VII) and Cr(VI) detection, the removal of Re(VII) and Cr(VI) by graphene oxide (GO) in water was monitored with the hydrogels used as a turn-off fluorescent sensing platform. The consistent results of the sorption isotherms of each metal on GO, which were obtained from the fluorescence spectra and by UV absorption, further verified the possibility of monitoring metal removal by fluorescence detection. Remarkably, GO removed 1186 mg/g of Re(VII) but only 178 mg/g of Cr(VI). The density functional theory (DFT) calculations indicated that both Re(VII) and Cr(VI) formed stable bonds with silica hydrogels, confirming that the interactions between the metal ions and the substrate would promote the fluorescence quenching of the supported CQDs. On the other hand, Re(VII) interacted more strongly with the carboxyl groups of GO than Cr(VI). In addition, a real-time detection system was designed to alarm the service life of a GO filter used for Re(VII) removal.
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yue Hu,Guangming Zhan,Xing Peng,Xiufan Liu,Zhihui Ai,Falong Jia,Shiyu Cao,Fengjiao Quan,Wenjuan Shen,Lizhi Zhang
In this study, we coated a high proton conductive shell on the zero-valent iron (ZVI) surface by mechanically ball-milling ZVI with oxalic acid dihydrate (OX-ZVI), and demonstrated that the generated FeC 2 O 4 ·2H 2 O shell dramatically improved the Cr(VI) removal rate of ZVI by about 15–80 times. Owing to a higher proton conductivity of FeC 2 O 4 ·2H 2 O shell than that of Fe 2 O 3 shell, proton could easily transfer through FeC 2 O 4 ·2H 2 O shell into iron core and be reduced to H, accompanying with fast surface-bound Fe 2+ generation, resulting in high efficiency of Cr(VI) removal in a wide pH range. Meanwhile, the removed Cr(VI) was deposited on OX-ZVI surface in the formation of Fe x Cr 1-x (OH) 3 composites, accompanied by the appearance of typical hollow structure derived from iron core dissolution. This study clarifies the significance of proton transfer on the reactivity of zero-valent iron, and also provides a new strategy to prepare highly active zero-valent iron for Cr(VI) removal.
✓ 已验证
DOI
高影响因子
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.
✓ 已验证
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2018
·
IF 1.2
Xuezhen Feng,Chunyan Liang,Jingang Yu,Xinyu Jiang
A binary composite consisting of graphene oxide (GO) and polyethylenimine (PEI) was fabricated by a facile physical mixing. Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM), thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and Zeta potential were used to characterize the prepared graphene oxide-polyethylenimine composite (GOPC). A series of experiments were carried out to investigate the effects of some important parameters, such as molecular weight of PEI, pH, time and temperature, on the adsorption efficiency of GOPC. Due to the high amine density of GOPC, its adsorption for Cr(VI) occurred more easily at lower pH mainly via electrostatic interaction. The adsorption process matched well with the Langmuir isotherm model and the pseudo-second-order kinetic model. The maximum adsorption capacity from the Langmuir model was 370.37 mg/g at pH 2.0 and 45°C for GOPC. Thermodynamic parameters revealed spontaneous and endothermic nature of the Cr(VI) adsorption onto GOPC. The main adsorption mechanism of GOPC toward Cr(VI) was electrostatic interaction. The adsorption-desorption experiments suggested GOPC was easily recycled and its stable adsorption capacity endowed it great potential as an adsorbent of Cr(VI) from wastewater.
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Daoyuan Nie,Rui Ma,Yanhong Zhang,Weiwei Wang,Guangze Nie,Guangbing Liu,Weijing Liu,Dong Zou
The development of an efficient and economical method to remove the toxic Cr(VI) from water is a global challenge. This study developed a new composite adsorptive membrane by combining polyacrylonitrile (PAN) as a substrate with crosslinked polyethyleneimine (PEI) to efficiently remove Cr(VI) from wastewater. After optimizing the preparation conditions of the material, the Cr(VI) removal by PEI/GMA@PAN was investigated using batch adsorption and longer-term filtration experiments. The composite adsorptive membrane exhibited a high adsorption capacity, reaching a maximum of 89.16 mg/g, along with fast adsorption kinetics that achieved equilibrium within 100 min for Cr(VI) removal. Even in the presence of coexisting ions, PEI/GMA@PAN membrane maintained a high efficiency in removing Cr(VI). The removal mechanism mainly relied on electrostatic interactions and the reduction of Cr(VI) to Cr(III). Notably, long-term filtration experiments substantiated the membrane's effectiveness in removing Cr(VI) from synthetic wastewater, with an impressive treatment volume of 342 L/m 2 . The optimized PEI/GMA@PAN membrane also demonstrated low PEI leaching across a wide pH range and the potential for re-utilization through four-round cycles, underscoring its promising applicability in wastewater treatment. Therefore, the newly synthesized composite membranes show potential for the removal of Cr(VI) from wastewater.
✓ 已验证
DOI
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.
✓ 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）