JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2022
·
IF 8.91
Xuyin Huang,Xiaojun Niu,Dongqing Zhang,Xiaoqin Li,Haoshen Li,Ziyuan Wang,Zhang Lin,Mingli Fu
While nanoscale zero-valent iron modified biochar (nZVI-BC) have been widely investigated for the removal of heavy metals , the corrosion products of nZVI and their interaction with heavy metals have not been revealed yet. In this paper, nZVI-BC was synthesized and applied for the removal of Cr(VI). Batch experiments indicated that the adsorption of Cr(VI) fit Langmuir isotherm, with the maximum removal capacity at 172.4 mg/g at pH 2.0. SEM-EDS, BET, XRD , FT-IR, Raman and XPS investigation suggested that reduction of Cr(VI) to Cr(III) was the major removal mechanism. pH played an important role on the corrosion of nZVI-BC, at pH 4.5 and 2.0, FeOOH and Fe 3 O 4 were detected as the major iron oxide , respectively. Therefore, FeOOH-BC and Fe 3 O 4 -BC were further prepared and their interaction with Cr were studied. Combining with DFT calculations, it revealed that Fe 3 O 4 has higher adsorption capacity and was responsible for the effective removal of Cr(VI) through electrostatic attraction and reduction under acidic conditions. However, Fe 3 O 4 will continue to convert to the more stable FeOOH, which is the key to for the subsequent stabilization of the reduced Cr(III). The results showed that the oxide corrosion products of nZVI-BC were subjected to the environment, which will eventually affect the fate and transport of the adsorbed heavy metal.
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高影响因子
Carbon Neutrality
·
2024
·Vol. 3
·期 1
·1-16
·
IF 0
Liu Xinghui,Naraginti Saraschandra,Zhang Fuchun,Sathishkumar Kuppusamy,Saxena Kuldeep K.,Guo Xiang
Environmental contamination by hexavalent chromium (Cr(VI)) and antibiotic drug residues pose significant challenges to public health and ecosystems. This study investigates the application of CoTiO 3 /BiVO 4 @MIL-Fe(53) (CT/BV@Fe-MOF) for the reduction of Cr(VI) and degradation of tetracycline (TCL) under visible light. After grafting an iron-based metal–organic framework MIL-Fe(53) on a modified CoTiO 3 /BiVO 4 composite, the photogenerated electrons could easily be transferred from CoTiO 3 to BiVO 4 /Fe-MOF species via interfacial charge transfer. UV–vis diffuse reflectance spectroscopy showed that charge carriers were formed in response to visible light absorption. The effect of different operating parameters, including catalyst load, pH, initial Cr(VI), and TCL concentration, was systematically evaluated during the photocatalytic process. The CT/BV@Fe-MOF composite exhibited 98.7% reduction efficiency in Cr(VI) (50 ppm) and 97.5% degradation efficiency towards TCL (30 ppm) within 90 min, resulting in a greater efficiency than the pristine CoTiO 3 , BiVO 4 , and Fe-MOF materials. The CT/BV@Fe-MOF composite displayed excellent stability over six cycles, highlighting its potential for practical applications. In addition, the plausible degradation pathway of TCL was evaluated using LC-ESI/MS analysis, while the TEST program was utilized to investigate the toxicity of the products generated during the degradation process.
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Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 31
·12561-12570
·
IF 0
Jian Hua Chen,Hai Tao Xing,Hong Xu Guo,Wen Weng,Shi Rong Hu,Shun Xing Li,Yi Hong Huang,Xue Sun,Zhen Bo Su
In this study, we prepare a polyethyleneimine (PEI) and graphene oxide (GO) composite adsorbent through an amidation reaction between the amine groups of the PEI and the carboxyl groups of the GO. Adsorption performance of the PEI–GO was tested by removing Cr(VI) ions from aqueous solution. The physico-chemical properties of the GO, pristine and Cr(VI) ions-loaded PEI–GO were investigated by FT-IR, SEM-EDX and XPS methods. To investigate the adsorption kinetics of Cr(VI) ions onto this newly developed PEI–GO, we performed a batch of experiments under different adsorption conditions: content of the PEI in the PEI–GO, solution pH, initial Cr(VI) ion concentration, adsorption temperature and contact time. The prepared PEI–GO exhibited an encouraging uptake capacity of 539.53 mg g−1. The adsorption process was fast, within the first 1 h, Cr(VI) ion adsorption onto the PEI–GO was about 71%, and the adsorption equilibrium could be obtained within 14 h. Kinetics experiments indicated that the adsorption process could be described by the pseudo-second-order kinetic model. Furthermore, our adsorption equilibrium data fit the Langmuir isotherms well (R2 > 0.99). The removal mechanism of Cr(VI) ions from the solution consists of two steps: (1) Cr(VI) ions bind to the 4PEI–GO composite by electrostatic interaction between the negatively charged Cr(VI) ion species and the protonated amine groups of the 4PEI–GO; and (2) a few Cr(VI) ions were reduced to Cr(III) ions with the assistance of π electrons on the carbocyclic six-membered ring of the 4PEI–GO and then bind on the 4PEI–GO by the electrostatic attraction between Cr(III) ions and negatively charged groups (COO−) of the 4PEI–GO. Based on the results obtained in this work, it can be concluded that the prepared PEI–GO can be an effective and potential adsorbent for removing Cr(VI) ions from an aqueous solution.
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SURFACE & COATINGS TECHNOLOGY
·
2024
·
IF 5.3
Xu Chuanqin,Zeng Zhikang,Li Xiaoya,Chen Tianyi,Peng Shusen,Ma Yongcun
The role of additives in surface treatments is pivotal for enhancing the functionality and performance of coatings. While the impact of additives on the functionality and performance of various types of coatings has been mechanistically investigated, the specific influence of additives on the durability of chromate-phosphate conversion coatings remains less understood. This study introduces a novel Cr(III) complex dye, which significantly improves the long-term durability of such coatings. Through comprehensive experimentation, it is demonstrated that the application of this dye markedly influences the morphology, chemical composition, element distribution, and modulus of the conversion film, with negligible effects on the film thickness. The paramount effectiveness of the dye is predominantly realized through the mitigation of bound water in the conversion film and the formation of a more stable structure via interaction with phosphate ions. This work contributes to the nuanced understanding of additive-coating interactions, highlighting the potential of specific chemical agents in advancing the durability of protective coatings.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Changwei Bai,Gang Yang,Shirong Zhang,Shihuai Deng,Yanzong Zhang,Chao Chen,Jingsong He,Min Xu,Lulu Long
A novel electrocatalytic anode (ECA)/α-MnO 2 /peroxymonosulfate (PMS) synergistic system was developed and evaluated for the removal of combined tetracycline (TC) and hexavalent chromium (Cr(VI)) pollution from waste waters. The factors affecting the efficiency of the removal of the combined pollutants, such as the synthesis time of the electrode, the amounts of raw materials, the PMS dose, the voltage, the initial pH and the coexisting ions were investigated. The breakdown products of PMS in the ECA/α-MnO 2 /PMS system improved the conductivity of the solution and the electrical current promoted the conversion of the valence state of Mn ions, resulting in a synergistic effect between the ECA and PMS activation processes, which improved the efficiency of removal of TC. The cathode chamber was fully utilized to simultaneously reduce Cr(VI). Synergistic effects occur in the ECA/α-MnO 2 /PMS system in appropriate ranges of the voltage or PMS dose, although the efficiency of the removal of TC depends mainly on the electrical current in the system. Both hydroxyl (•OH) and sulfate (SO 4 •− ) radicals played important parts in the degradation of TC. The main degradation products of TC were identified and degradation pathways proposed. The synergistic effects between the ECA process and a Fenton-like process was studied, providing a new approach for the study of electro-Fenton technology and the removal of combinations of TC and Cr(VI) from waste waters.
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高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 7
·3935-3943
·
IF 7.443
Dongfang Hou,Xianluo Hu,Wingkei Ho,Pei Hu,Yunhui Huang
Novel porous Cr-doped SrTiO3 nanotubes were fabricated using a simple and economical electrospinning technique with subsequent calcination. The average outer diameter of the nanotube was approximately 100 nm, and the multimodal porous netlike framework with high specific surface area was favorable for light harvesting and matter diffusion. Photocatalytic activity was evaluated by degradation of azo dye acid orange 7 and removal of NO under visible light irradiation. The enhanced photocatalytic activity of porous Cr-doped SrTiO3 nanotubes was attributed to the one-dimensional tube-like architecture, high specific surface area, multimodal pore size distribution, and proper Cr doping.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Lanlan Li,Zhiyang Wei,Xiaowei Liu,Yunhe Yang,Chenxun Deng,Zhimin Yu,Zhi Guo,Jianghong Shi,Chengzhu Zhu,Wei Guo,Zhenjie Sun
Chitosan (CS) is an attractive bio-adsorbent in pollutant removal due to its environment-friendly properties and abundant adsorption sites. However, the weak mechanical properties and strong dissolubility in acidic conditions of CS hinder its wide application. Herein, a facile method was proposed to fabricate polydopamine (PDA) and CS cross-linked graphene oxide (GO) (GO/CS/PDA) composite aerogel for Cr (VI) removal. GO was cross-linked with CS, forming a reinforced and three-dimensional macroporous structure; the introduced PDA was simultaneously cross-linked with CS and GO, providing more abundant nanopores and active sites for Cr(VI) removal. Based on the batch experiment results, GO/CS/PDA exhibited an optimized mass ratio (1:20:2) of GO, CS, and PDA for the most effective Cr(VI) adsorption; the adsorption removal rate of Cr(VI) was pH dependent, with the highest removal rate at pH = 3.0. The pseudo-second-order kinetic and Freundlich models were more suitable for fitting the adsorption kinetics and adsorption isotherms, respectively, and the maximum adsorption capacity for GO/CS/PDA was 312.05 mg/g at 298 K. Thermodynamics parameters indicated that the adsorption was a spontaneous and exothermic process. The excellent mechanical integrity and reusable adsorption performance of GO/CS/PDA promise the adsorbent with satisfactory reusability.
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高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Xiaoyu Lin,Xi He,Ling Lei,Yufeng Zhao,Longzhe Cui,Guiping Wu
Cr(VI)-contaminated water poses a serious threat to the environment. In this study, capsule-type biosorbent Aliquat-336-filled chitosan capsules (AFCCs) were prepared by a simple and gentle method for more efficient and eco-friendly removal of Cr(VI). The experimental results show that the uptake of Cr(VI) by AFCCs increased with increasing Aliquat-336 content. The AFCCs show excellent stability under acidic conditions, and the maximum adsorption capacity was reached at a pH of 2. The maximum adsorption capacity of AFCCs for Cr(VI) was 110.94 ± 5.07 mg/g at 20 °C, which was calculated based on the Langmuir model. The kinetic results show that the adsorption rate control process changed from liquid film diffusion to a chemical reaction with increasing shaking rate. In addition, the AFCCs and adsorption-reduction mechanism of Cr(VI) were characterized by digital photography, electron microscope , zeta potential , Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The results indicated that the electrostatic attraction between quaternary amine groups in Aliquat-336 and Cr(VI) anions plays a major role in the removal of Cr(VI). Subsequently, the adsorbed Cr(VI) obtained electrons from C C/C H and NH 3 + / NH 2 + were reduced to Cr(III), while C C/C H and NH 3 + / NH 2 + were oxidized to C O, C O, =NH + , =N and N O, respectively.
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高影响因子
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
·
2021
·Vol. 27
·期 3
·640-654
·
IF 1.993
Xiaoqi Liu,Yan Liu,Ting'an Zhang
This study aimed to prepare an efficient, cost-effective, and separable magnetic zeolite/chitosan composite (MZFA/CS) adsorbent from solid waste to deal with the water pollution of Cr(VI). The MZFA/CS was characterized by X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and vibrating sample magnetometer (VSM) techniques. Then, the effect of pH, temperature, initial concentration of Cr(VI) ions, and contact time was considered in the study. For a sorbent dose of 0.1 g in 50 mL of a Cr(VI) solution, at a contact time of 30 min, temperature of 30°C, and a pH of 3, an adsorption capacity ( q e ) of 16.96 mg g −1 was achieved. Adsorption kinetics and isotherm data obtained for all adsorption systems were well-fitted by pseudo-second-order and Langmuir models, respectively. The thermodynamic study suggested that the adsorption process is spontaneous and endothermic in nature. In summary, the adsorbent with better separability ( Ms = 16.83 emu g −1 ) and adsorbability was successfully fabricated.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Wanqing Zhang,Zhongyin Zhang,Yuanchao Li,Jun Chen,Xiaobo Li,Yadong Zhang,Yuping Zhang
A novel MIL-101(Cr)/XC-72 modified glassy carbon electrode (GCE) sensor was fabricated to determine chloramphenicol (CAP). The electrochemical sensors were constructed by using MIL-101(Cr), XC-72, MIL-101(Cr)/XC-72, and their electrochemical performances were studied with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. In comparison with the GCE , MIL-101(Cr)/GCE and XC-72/GCE sensors, the MIL-101(Cr)/XC-72/GCE sensor exhibited a well-defined redox peak towards CAP in phosphate buffer solution (PBS). The effects of the ratio of MIL-101(Cr) and XC-72, accumulation time, scan rate, and pH value were carefully considered. Under the optimized conditions, the sensor exhibited excellent response for CAP. The linear concentration ranges of CAP were from 1.0 × 10 −8 to 2.0 × 10 −5 M (R 2 = 0.985), with a low detection limit of 1.5 × 10 −9 M (S/N = 3). Furthermore, the MIL-101(Cr)/XC-72/GCE sensor was successfully applied to the determination of the real samples with satisfactory recoveries.
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高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Sun Qian,Wang Changlong,Zhang Lixin,Yang Yanzhao
The high pathogenicity to organisms and high destructiveness in the natural environment determine the utmost importance of removing Cr(VI) from water. Herein, thiourea crosslinked-amino modified graphene nanoflakes (TAGN) was prepared by simple ring opening reaction and silanization reaction and the Cr(VI) adsorption performance was investigated. Results manifested that TAGN presented three-dimensional porous structure with abundant folds and avoided agglomeration. The adsorption experiments indicated that the optimal test pH value was 2 and the most suitable adsorbent dosage was 1 g/L. Under the optimum adsorption conditions, TAGN exhibited an outstanding adsorption capacity of 193.77 mg/g for Cr(VI) in water. Various characterizations and tests such as Zeta potential , FTIR, XPS as well as isotherms and kinetics revealed that the adsorption of TAGN for Cr(VI) was more consistent with Freundlich isotherm model and pseudo-second-order kinetic model , confirming a multilayer chemisorption process dominated by multiple combination mechanisms: electrostatic interaction, reduction reaction, complexation and hydrogen bonding interaction. Under the condition of coexistence of multiple metal ions , the TAGN could still maintain superb selectivity of 63.9% towards Cr(VI). After ten cycling test, 81.8% removal efficiency of Cr(VI) was guaranteed. Therefore, TAGN possessed high adsorption capacity , excellent selectivity and prominent cyclic regeneration ability. This work provided a promising nanosorbent for the field of water cleaning, especially for the elimination of heavy metal ions .
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高影响因子
MATERIALS RESEARCH BULLETIN
·
2018
·
IF 2.873
Xiao Jiang,Qing-Da An,Zuo-Yi Xiao,Shang-Ru Zhai,Zhan Shi
A cost-effective and chemically modified biological adsorbent based on agricultural wasted husks for heavy metal removal was fabricated by coating with Polydopamine–Polyethylenimine via the mussel inspired chemistry. Batch and fixed bed column adsorption experiments were carried out to explore the sorption capacity and potency of industrial application. The batch results indicated that the maximum adsorption capacity reached 42.8 mg/g which is much larger than most adsorbents based on bioresource and agricultural wastes for Cr(VI) removal in aqueous solution simultaneously with excellent recycling performance. In column adsorption experiments, it exhibited high mechanical stability and applied potential. The equilibrium time was 9130 min under the flow rate of 1 ml/min, and reached the equilibrium adsorption capacity of 47.14 mg/g. The breakthrough curves ploted by the data of fixed bed experiments under different flow rates (1 ml/min & 2 ml/min) fitted the Thomas model with R 2 of 0.9510 and 0.9437 respectively.
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高影响因子
危险品化学品经营许可证（带存储）