CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Haonan Ma,Chi Zhang,Long Chen,Mengning Xi,Zhiqiang Wang,Zheng Ni,Kecheng Zhu,Hanzhong Jia
Sorption processes at the mineral–water interface are of great importance in dominating the fate and availability of metalloid contaminants in natural environment. Aiming at a thorough understanding of the complexation of antimony (Sb) on metal hydroxide, we conducted first-principles molecular dynamic (FPMD) simulations and batch adsorption experiments to elucidate the quantitative mechanism of Sb complexation on Mg(OH) 2 . Batch experiments showed the sorption of Sb(III) is nearly pH-independent, while increasing pH markedly weakened Sb(V) sorption; the measured sorption isotherm curves were well fitted by Langmuir model. Subsequently, molecular-level mechanism of Sb(V)/Sb(III) on brucite basal and edge surfaces were revealed by FPMD, including microscopic surface reactive sites, local complexing structures and coordination geometries, and complexing free energies. Results showed that Sb(III)/Sb(V) can form outer-sphere complexation on basal surface by hydrogen bonding. On edge surface, Sb(III)/Sb(V) formed stable inner-sphere mononuclear monodentate and binuclear bidentate complexes. The calculated free energies indicated that the binuclear bidentate complexing was more favorable than monodentate structure, and the complexation of Sb(III) was more stable than Sb(V). Accordingly, reaction pathway of the ligand exchange and thermodynamic stability of the different inner-sphere complexes were clarified. This study provides theoretical basis for evaluating the environmental risk of Sb and improving the engineering efficiency of Sb-contaminated water management.
研究领域:
环境科学
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化学
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材料科学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Xiaolin Zhang,Ping Huang,Siyao Zhu,Ming Hua,Bingcai Pan
Toxic metals are usually present as organic complexes in high-salinity effluents from various industries. The efficient removal of such metal complexes is an imperative but still challenging task due to their stable structure and high mobility. Herein, we propose a new strategy to remove Cu-carboxyl complexes from high-salinity water by using a commercially available nanocomposite HZO-201, i.e., nanohydrated zirconium oxide (HZO) confined inside anion exchanger D201. In contrast to D201 and a cation exchanger D001, which both adsorb Cu-citrate negligibly, HZO-201 exhibits preferable adsorption toward Cu-citrate (∼130 mg Cu/g-Zr) at high salinity (1.5 wt % NaCl). On the basis of scanning transmission electron microscopy energy-dispersive spectrometry (STEM-EDS), attenuated total reflection Fourier transform infrared (ATR-FTIR), and X-ray photoelectron spectrometry (XPS) analysis, the formation of ternary complex among Cu(II), citrate, and the embedded nano-HZO is evidenced to be responsible for the removal of Cu-citrate. The exhausted HZO-201 can be regenerated with a binary HCl-NaCl solution for repeated use for 5 cycles without capacity loss. Fixed-bed adsorption demonstrates that HZO-201 column is capable of producing ∼1150 bed volume (BV) clean water (<0.5 mg Cu/L) from simulated high-salinity wastewater, whereas only ∼10 BV and ∼60 BV was produced for the D001 and D201 columns, respectively. Furthermore, HZO-201 shows excellent removal of Cu(II) complexes with three other carboxyl ligands (oxalate, tartrate, and succinate).
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2013
·
IF 1.164
Jiahui Shao,Shu Qin,Wenxi Li,Yiliang He
Simultaneous recovery of nickel and cobalt from aqueous solutions by complexation-ultrafiltration process with polyethylenimine (PEI) was studied. Experiments were performed as a function of polymer/metal ratio (P/M), solution pH, and ionic strength. Effects of concentration time on metal rejection and membrane flux were also studied. At optimum experimental conditions of pH 6.0 and P/M 5.0, the nickel removal efficiency reaches at 99.9% and cobalt removal efficiency goes to 96.4%. Both nickel and cobalt removal efficiencies decreased as the adding salt concentration increases. During 12 h of the ultrafiltration process, the decline of membrane flux was less than 16% and the removal efficiencies for both nickel and cobalt were kept almost constant. Diafiltration was further performed to regenerate PEI. The removal efficiencies for both metals using recycled PEI were found to be close to those with the original PEI. Results from the two-step process of complexation-UF and decomplexation-UF separation showed that it could be a promising method for simultaneous recovery of nickel and cobalt from aqueous solutions.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2012
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IF 0.826
Jianxian ZENG,Xiahui SUN,Lifeng ZHENG,Qincheng HE,Shu LI
Polyquaternium-6 (PQ6) as the water-soluble polymer was used for complexing the anion forms of tungsten (VI) before ultrafiltration. Tungsten (VI)-PQ6 complex was retained by polysulfone hollow fiber ultrafiltration membrane in the complexation-ultrafiltration process. Effects of various operating parameters such as polymer metal ratio(PMR), pH and chloride ion concentration on permeate flux ( J ) and tungsten rejection coefficient ( R ) were investigated. The integration of four experiments including concentration, decomplexation, diafiltration and reuse of regenerated polymer was carried out. In the process of concentration, J declines slowly and R is about 1 at PMR of 3 and pH of 7. Tungsten concentration in the retentate increases linearly with volume concentration factor. Tungsten is concentrated efficiently with the membrane. The concentrated retentate was used further for the decomplexation. It takes about 6 min to reach the decomplexation equilibrium at chloride ion concentration of 50 mgL −1 . The decomplexation percentage of tungsten (VI)-PQ6 complex reaches 56.1%. In the diafiltration process, tungsten (VI) can be extracted effectively by using 50 mgL −1 chloride ion solution, and the purification of the regenerated PQ6 is acceptably satisfactory. The regenerated PQ6 was used to bind tungsten (VI) at various pH values. The binding capacity of the regenerated PQ6 is close to that of fresh PQ6, and the recovery percentage of binding capacity is higher than 90%.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
·
2025
·Vol. 122
·期 12
·e2501354122
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IF 9.1
Leiming Lin,Zheng Li,Jun Ren,Ying Meng,Fubo Luan
The co-occurrence of arsenic and uranium in groundwater has been found in many countries, posing a significant challenge to human health. Here, we have demonstrated the efficient simultaneous removal of arsenic and uranyl-carbonate complexes from groundwater using {001}-TiO2. Surprisingly, the presence of U(VI) greatly enhanced the adsorption of As(V) on {001}-TiO2, while As(V) had a negligible impact on U(VI) adsorption. Through in situ ATR-FTIR spectroscopy, we uncovered a mechanism involving the formation of a ternary surface complex [Ti–U(VI)–As(V)] on the surface of {001}-TiO2. This ternary surface complex formed through the substitution of CO32- from uranyl coordination sites. Furthermore, the adsorbed As(V) and U(VI) can be easily recovered using a sodium hydroxide solution, and {001}-TiO2 can be used repeatedly. Our findings offer a promising solution for the simultaneous removal of As(V) and U(VI) from groundwater and provide valuable insights into the mechanisms involved in their removal.
研究领域:
环境科学
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化学
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产品关联
DOI
PubMed
高影响因子
Water
·
2022
·Vol. 14
·期 9
·1420
·
IF 3.53
Juan Peng,Yameng Ma,Xiao Huang,Jianghua Yu,Fengjiao Yu,Jingsi Gao
Ni-ethylenediaminetetraacetic acid (Ni-EDTA) poses serious threats to the ecological environment and human health, due to its acute toxicity and low biodegradability. The decomplexation efficiency of Ni-EDTA through the conventional Fenton process has been constrained to pH; thus, other appropriate approaches are required to destroy the stable chelate structure at a neutral pH. In this study, the effect of operating parameters such as the pH, Fe2+concentration, particle electrode dosage, current density, and coexisting ions was studied. The results revealed that the 3D-EF system owned advantages for the removal of Ni-EDTA in the broadening of the pH application window. The Ni-EDTA removal efficiency in the 3D-EF system reached 84.89% after 120 min at a pH of 7. In addition, the presence of coexisting ions slightly affected the decomplexation efficiency of Ni-EDTA.Keywords:Ni-EDTA;three-dimensional electro-Fenton;neutral pH;decomplexation
研究领域:
环境科学
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化学工程
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DOI
高影响因子
CRYSTENGCOMM
·
2015
·Vol. 17
·期 42
·8113-8118
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IF 4.034
Liao Chen,Tao Ye,Xinyi Jin,Jie Ren,Boning Huang,Zhi-Kang Xu,Hongzheng Chen,Hanying Li
Crystallization in gel media has been occasionally found to result in single crystals with gel networks incorporated inside, extending the gel method with a long history for crystallization into a platform to design the internal composite structures of a crystal. The limited number of gel-incorporated crystals has inspired the investigation on how general gel incorporation is. Crystallization in gels through decomplexation has been widely used to grow crystals with extremely low water solubility, while whether the gel networks are incorporated inside these crystals has not been studied. In this work, crystals of AgCl, AgI and CuCl have been grown in both agarose gels and silica gels by decomplexation. The crystallographic structures of the crystals were identified by powder and/or single X-ray diffraction. The internal hybrid structures were studied by examining the residue materials after gentle etching and complete dissolution of the crystals. When grown from agarose gels containing self-assembled fibrous structures, gel networks were incorporated into single crystals of all the three compounds. In sharp contrast, the gel networks were pushed away when the crystals were grown in silica gels. The discrepancy between the crystals grown from agarose gels and those from silica gels is consistent with the effect of gel strength on gel incorporation. This work may help to harvest gel-incorporated crystals.
研究领域:
晶体学
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材料科学
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DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
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2012
·Vol. 7
·期 6
·940-947
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IF 0.758
Jianxian Zeng,Qincheng He,Hu Zhou,Xiahui Sun,Jiaojiao Zhang
Complexation–ultrafiltration process was investigated for cerium(III) recovery from aqueous solutions by using poly (acrylic acid) sodium salt (PAASS) as a complexing agent. The adsorption of cerium(III) on PAASS was preliminarily studied at different pH values. Next, effects of pH, polymer metal ratio (PMR), calcium(II) and competitive complexing agents on permeate flux ( J ) and cerium rejection coefficient ( R ) were investigated in the total recirculation mode. Finally, the integrations of four experiments including concentration, decomplexation, regeneration of PAASS and reuse of regenerated PAASS were carried out. Obtained results show that the adsorption can be described well using the Langmuir equation. If pH is reduced below 4, J decreases rapidly. PMR has negligible effect on J . R increases with increasing pH or PMR. Calcium(II) and ethylenediaminetetraacetic acid disodium salt have the effects on R , but these effects can decrease by increasing pH. Tartrate sodium does not influence R . In the process of concentration, J declines slowly, and R is about 1. It takes 40 min to reach the decomplexation equilibrium at pH 3. The decomplexation percentage of cerium(III)–PAASS complex is about 70%. In the regeneration of PAASS, cerium(III) can be removed effectively, and the purification of regenerated PAASS is acceptably satisfactory. The binding capacity of regenerated PAASS is close to that of fresh PAASS, and the recovery percentage of binding capacity is higher than 90%. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
H. Xiao,Z. Yao,Q. Peng,F. Ni,Y. Sun,C.X. Zhang,Z.X. Zhong
Separation of squalene, a type of terpenoid hydrocarbons with important biological properties, from camellia oil by silver ion complexation was studied. We showed that the UV–visible absorption wavelength of squalene in AgNO 3 -methanol solution was obviously red-shifted, and the infra-red vibration wavelength of C C bond slightly decreased, indicating that complexation between squalene and Ag + took place. The distributions of squalene in AgNO 3 methanol solution/petroleum ether under different conditions were further investigated. We found that the fraction of squalene in AgNO 3 -methanol phase was enhanced with increased percentage of methanol and AgNO 3 concentration and decreased extraction temperature. The distribution coefficient of squalene was up to 7.87 under optimum extraction conditions with 70% methanol (v/v), 0.6 mol/L AgNO 3 , reaction time of 12 h, and at the temperature of 0 °C. Furthermore, under the optimum conditions, extraction of squalene from the unsaponifiable portion of camellia oil exhibited high selectivity with a raffinate rate and a back-extraction rate of 73.9% and 72.5%, respectively. The purity of extracted squalene was 37.8%, 108 times more concentrated than that in the starting material.
研究领域:
生物化学
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分离技术
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Zhe Xu,Tiancheng Wu,Yu Cao,Congcong Chen,Shanming Ke,Xierong Zeng,Peng Lin
A promising strategy to treat wastewater containing heavy metal complexes (HMCs) is to employ oxidation processes before carrying out the conventional processes. Metal ion-catalyzed oxidation processes (MICOPs) have been confirmed to be suitable for the remediation of wastewater. However, the treatment of HMCs by MICOPs has seldom attracted researchers’ attention and the key mechanisms remain unclear. In this study, Cu II -ethylenediamine tetraacetic acid (EDTA) was used to evaluate the decomplexation efficiency of various MICOPs, among which the Co II /peroxymonosulfate (PMS) system provided the best results. In-depth analysis of the decomplexation mechanism of Cu II -EDTA indicated that the high affinity of Cu(II) to EDTA inhibits the exchange between Co II and Cu II in Cu II -EDTA, thus preventing the chelation of the catalytically active Co 2+ with EDTA, which leads to the rapid decomplexation of Cu II -EDTA. Moreover, through thermodynamic computation, Mn II -EDTA, Cd II -EDTA, and Ni II -EDTA were selected as other HMC candidates to investigate their influence on the oxidation efficiency of the Co II /PMS system. The results confirmed that the oxidation efficiency of Co II /PMS is strongly dependent on the metal-ion replacement. Finally, we propose that the distinct performance of the Fenton(-like) process in decomplexing the Ni II -EDTA and Cu II -EDTA could be well explained by the metal-ion replacement mechanism.
研究领域:
环境科学
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化学工程
·
水处理
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Miaomiao Zhao,Zezhou Zhang,Liying Wang,Xuan Xu,You Li,Ao Liu,Degang Ma,Chunfeng Song
Stable, treatment-resistant Cu complexes in practical wastewater are frequently neglected. Positively charged lysozyme amyloid fibrils (AF), however, exhibit unexplored potential for their adsorption. This study engineered an amyloid fibril-chitosan composite (AF-CS) xerogel and evaluated its adsorption performance in three systems: free Cu 2+ , Cu-Citrate binary, and Cu-EDTA binary. The characterization confirmed successful synthesis of AF-CS, revealing a porous and amine-rich structure with a more positive surface charge than that of pure AF xerogel. Systematic evaluation demonstrated adsorption capacities of 65.37 mg/g (free Cu 2+ ), 166.14 mg/g (Cu-Citrate), and 40.31 mg/g (Cu-EDTA). MINTEQ 3.0 speciation analysis identified anionic Cu-ligand complexes as dominant species in binary systems. Further investigation revealed synergistic adsorption mechanisms in the Cu-Citrate system: electrostatic attraction coupled with decomplexation-complexation pathways liberated citrate ligands, enabling electrostatic shielding and adsorption bridging that enhanced Cu coordination. Conversely, the high stability of Cu-EDTA chelates limited adsorption primarily to mechanisms involving electrostatic attraction, resulting in suboptimal performance. These findings advance the theoretical understanding of AF-CS interactions with diverse Cu species, demonstrating AF-CS as a promising material for Cu recovery from complex wastewater and providing guidance for designing novel remediation materials.
研究领域:
环境科学
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材料科学
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化学工程
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
WATER AIR AND SOIL POLLUTION
·
2016
·Vol. 227
·期 8
·1-10
·
IF 1.551
Chen Zhenhe,Li Guoao,Sun Liquan,Li Ye
Metal cations could enhance the sorption of tetracyclines but sometimes the effects are negligible. It is still not clear how these metals produce different effects. In this study, the sorption of chlortetracycline (CTC), tetracycline (TC), and oxytetracycline (OTC) was performed in the presence of Cd (II) to reveal the unknown mechanisms with two river sediments. It is found that Cd (II) could enhance the sorption of TCs on sediment SS, while it is negligible on sediment SY. For different tetracyclines, the enhancement effect by Cd (II) was more significant for CTC, while it is inferior for OTC and TC. Sorption isotherms of Cd (II) under strong and weak background electrolyte and pH decrease of sorption solutions indicate specific sorption is major on SY and cation exchange is significant on SS. Consequently, specific sorption is unfavorable for the enhanced sorption of TCs in the presence of Cd (II) because it is not favorable for the sorption of Cd-TCs by complexation and cation exchange. By the theoretical calculations, it is found that the significant enhancement of CTC is due to the higher electron affinity of Cd-CTC complex than the others to the surface groups. In conclusion, TCs sorption will not be affected by Cd (II) on sediments or soils with strong specific sorption characters of Cd (II).
研究领域:
环境科学
·
土壤学
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DOI
高影响因子
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