CARBOHYDRATE POLYMERS
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2020
·
IF 7.182
Jinfeng Mei,Hui Zhang,Siqi Mo,Yuzhe Zhang,Zhongyu Li,Hongxiang Ou
Low-density aerogels with three–dimensional porous structure were synthesized using soluble chitosan oligosaccharide (COS) and graphene oxide (GO) as raw materials under mild conditions. Tetraethylenepentamine was used as the crosslinker of COS and the bridge between GO and COS, as well as the provider of functional groups. Structural characterizations revealed that crosslinked COS polymers firmly fixed on the surfaces of GO sheets and abundant amino groups homogeneously distributed in the pores. The adsorption capacity of the aerogel for Cr(VI) can reach up to 519.8 mg/g, while the adsorption efficiency for trace Cr(VI) adsorption can also reach 100% especially. The adsorption mechanism was investigated with X–ray photoelectron spectroscopy and zeta potential analysis. The superb properties suggested that the strategy of using COS as a raw material for the fabrication of adsorbents with controllable structure and form is meaningful.
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高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 10
·2580
·
IF 5.076
Jien Ye,Yating Luo,Jiacong Sun,Jiyan Shi
The aggregation of nanoscale zero-valent iron (nZVI) particles and their limited transport ability in environmental media hinder their application in environmental remediation. In this study, the Cr(VI) removal efficiency, transport performance, and toxicity of nZVI and bentonite-modified nZVI (B-nZVI) were investigated. Compared with nZVI, B-nZVI improved the removal efficiency of Cr(VI) by 10%, and also significantly increased the transport in quartz sand and soil. Increasing the flow rate can enhance the transport of nZVI and B-nZVI in the quartz sand columns. The transport of the two materials in different soils was negatively correlated with the clay composition. Besides, modification of nZVI by bentonite could reduce toxicity to luminous bacteria (Photobacterium phosphereumT3) and ryegrass (Lolium perenneL.). Compared with Fe-EDTA, the transfer factors of nZVI and B-nZVI were 65.0% and 66.4% lower, respectively. This indicated that although iron nanoparticles accumulated in the roots of ryegrass, they were difficult to be transported to the shoots. The results of this study indicate that B-nZVI has a strong application potential in in situ environmental remediation.Keywords:nanoscale zerovalent iron (nZVI);hexavalent chromium;bentonite;toxicity
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高影响因子
Journal of Environmental Chemical Engineering
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2020
·
IF 4.3
Wei Jiahao,Cai Weiquan
Carbon microspheres have attracted considerable interest in the field of heavy metal wastewater treatment. Herein, waste peanut hull derived N-doped spherical carbons (WPHSC) were successfully prepared by a one-step mild hydrothermal method. The obtained samples were characterized by XRD, SEM, FT-IR and XPS. The adsorption tests indicated that the WPHSC show excellent adsorption performance for Cr(VI) with the maximum adsorption capacity of 181.82 mg g −1 . While treating the real electroplating wastewater with a WPHSC dosage of 4 g L −1 , the Cr concentration significantly decreased from 652.96 mg L −1 to 113.42 mg L −1 . The adsorption mechanism attributes to the electrostatic attraction and redox reaction between Cr(VI) and WPHSC. Importantly, this method can be extended to other waste plant biomass, including sunflower seed hulls, walnut shell, coconut shell and corncob as carbon sources. The adsorption removal efficiencies of the obtained carbon spheres for 100 mg L -1 Cr(VI) are all over 99.5 % with low residual concentrations less than 0.5 mg L −1 . This universal study expands the scope of renewable raw materials for preparing carbon spheres with great application potential in the field of chromium-containing wastewater treatment.
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高影响因子
Open Chemistry
·
2020
·Vol. 18
·期 1
·97-107
·
IF 1.216
Huayu Huang,Yang Wang,Yubin Zhang,Zhiying Niu,Xinli Li
Amino-functionalized graphene oxide (GO-NH 2 ) was synthesized by grafting (3-aminopropyl) triethoxysilane on the graphene oxide (GO) surface. The GO-NH 2 with high surface area and numerous active sites can efficiently adsorb Cr(VI), Cu(II), Pb(II) and Cd(II) ions. The maximum adsorption capacities of GO-NH 2 for Cr(VI), Cu(II), Pb(II) and Cd(II) were 280.11, 26.25, 71.89 and 10.04 mg g −1 , respectively. The pseudo-first-order and pseudo-second-order kinetic models were employed to describe the kinetic processes. The experimental data agreed well with the pseudo-second-order kinetic equation, and the adsorption of heavy metals onto GO-NH 2 occurs via chemical adsorption. The characteristics of Cr(VI), Cu(II), Pb(II) and Cd(II) in the GO-NH 2 adsorption processes were analyzed using the Langmuir and Freundlich isotherm models. The adsorption processes of Pb(II) and Cd(II) on GO-NH 2 were fit by the Langmuir model. The Freundlich isotherm model was well correlated to Cr(VI) and Cu(II). The GO-NH 2 is a promising material for the removal of heavy metal ions from industrial wastewater. This study provides an effective pathway to process industrial wastewater, and the GO-NH 2 has a good adsorption effect for the treatment of heavy metals in industrial wastewater.
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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
CELLULOSE
·
2022
·Vol. 29
·期 6
·3389-3406
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IF 6.123
Lang Daning,Xu Xia,Wu Ronglan,Wang Wei,Shi Ming,Jia Ke,Chen Shifei,Wang Jide
A cellulosic material has been synthesized that could efficiently and selectively adsorb organic and inorganic contaminants from aqueous solutions without interference from competing adsorption sites. Cellulose-graft-tetraethylenepentamine molecular imprinted polymer (C-TEPA-MIP) was synthesized by using 4-nitrophenol (4-NP) as the template. The C-TEPA-MIP adsorbent could adsorb 4-NP and Cr(VI) simultaneously and selectively, without being affected by the competitive adsorption sites of each of these pollutants. The adsorption of 4-NP was predominantly due to the imprinted sites of 4-NP in C-TEPA-MIP that were located inside of the adsorbent, whereas that of Cr(VI) was primarily due to the amine groups of TEPA found on the surface of the adsorbent. Compared with the non-imprint polymer synthesized without the template, C-TEPA-MIP showed higher selectivity for both 4-NP and Cr(VI) in unitary and binary systems. In addition, C-TEPA-MIP exhibited good stability and recyclability for 4-NP, which makes it a promising candidate material for applications concerning wastewater treatment. Graphical abstract
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高影响因子
APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Lei Wang,Haris Muhammad,Minwang Laipan,Xiaohu Fan,Junkang Guo,Yongtao Li
The demand for clean water and soil drives high efficiency, less expensive, and eco-friendly clay-composites as adsorbents for remediation of heavy metals polluted environment. We have developed a new water remediation technique by using an organic-inorganic composite, L-cysteine doped polypyrrole modified bentonite (L-cys/PPy/BT) for removal of Cr(VI) and Mo(VI). The L-cys/PPy/BT showed maximum adsorption capacities of 318.5 and 65.4 mg/g for Cr(VI) and Mo(VI) respectively. For Cr(VI) and Mo(VI) the sorption process on L-cys/PPy/BT followed the Freundlich and Langmuir isotherm models, respectively. Furthermore, the pseudo-second-order kinetic model described the adsorption behavior of Cr(VI) and Mo(VI). Moreover, the thermodynamic parameters indicated that sorption processes were endothermic and spontaneous. Mechanistic assessment revealed that adsorption of Mo(VI) on L-cys/PPy/BT could be attributed to chelation, electrostatic attraction and ion-exchange of Mo(VI) with the imine/amine functional groups in the material's matrix , while electrostatic attraction, ion exchange, chelation and redox reaction played a significant role in the removal of Cr(VI). This research provides a new approach for the use of clay materials as potential sorbents for removal of heavy metal ions in contaminated water .
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高影响因子
Nanoscale
·
2025
·
IF 5.1
Wei Zhao,Yuxiang Yang,Yanbin Li,Yimin Liu,Yuezhou Wei,Xinpeng Wang,Deqian Zeng
The advancement of efficient photocatalysts is essential for tackling global energy and environmental issues. In this work, a unique sheet-on-sheet Cd(OH)2/CdS photocatalyst was synthesized via a facile solution strategy, demonstrating significantly improved photocatalytic performance for H2 generation and Cr(VI) reduction. The optimal 5% Cd(OH)2/CdS obtained an impressive H2 production rate of 3475 μmol·g-1·h-1 under visible light, marking a 6.3 times increase compared to CdS. Additionally, the kinetics of Cr(VI) reduction were markedly accelerated, with a rate constant of 0.2803 min-1, representing a 5.7 times improvement over pure CdS. Moreover, the 2D/2D Cd(OH)2/CdS photocatalyst exhibited exceptional stability, maintaining high photocatalytic activity over multiple reaction cycles. Experimental findings and DFT calculations revealed the charge transfer mechanism between CdS nanosheets and Cd(OH)2 cocatalyst. This work provides insights into designing high-performance CdS-based nanophotocatalysts for water splitting and environmental remediation.
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产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
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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
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
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
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
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