JOURNAL OF HAZARDOUS MATERIALS
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2022
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IF 14.224
Shiwei Xie,Chang Li,Hui Zhan,Wei Shao,Yuanxin Zhao,Peng Liu,Peng Liao
Fe-based replacement and precipitation are promising methods for removal of copper ethylenediaminetetraacetic acid (Cu(II)-EDTA) but are limited by the necessity of controlling pH and dissolved oxygen. The details of the decomplexation mechanism also remain unclear. The present work investigated an anoxic iron electrocoagulation process capable of automatically modulating anoxic conditions and solution pH during exposure to air and thus promoting the rapid and thorough decomplexation of Cu(II)-EDTA. Dissolved Fe (II), rather than Fe(II)-bearing minerals, was found to be primarily responsible for the reduction of Cu(II)-EDTA to Cu(I)-EDTA and for the subsequent replacement reaction to generate free Cu(I) ions within the initial pH range of 2–7. The Cu(I) was primarily precipitated as Cu 2 O on the surface of green rust and magnetite as the pH was increased. The aeration of these Fe-containing precipitates released free Cu(I) ions instead of chelated Cu into solution, allowing for recycling of the Cu. This release of Cu(I) was likely induced by the pH decrease during aeration. This study provides important insights regarding the reductive decomplexation of chelated Cu(II) and the recovery of Cu via anoxic iron electrocoagulation, which is a promising green approach to recycling Cu from wastewater.
研究领域:
环境科学
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废水处理
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PubMed
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
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IF 19.503
Sheng Liang,Xiaoting Hu,Haolin Xu,Zhenchao Lei,Chaohai Wei,Chunhua Feng
The present study aims to gain molecular insights into how peroxomonosulfate (PMS) reacts with ethylenediaminetetraacetic acid (EDTA)-Ni II at alkaline pH by conducting experimental tests and density functional theory (DFT) calculations. We first show experimental evidence that the decomplexation of EDTA-Ni II and simultaneous formation of Ni hydroxide precipitates can be successfully achieved with the addition of PMS under alkaline conditions. At pH 11.0 or above, the aqueous Ni concentration is substantially reduced from 2.0 to below 0.1 mg L −1 within 60 min. We then propose an alternative reaction pathway in which Ni II rather than EDTA is attacked by PMS, leading to the production of high-valent Ni species (in the form of EDTA-Ni IV =O). This is a key and highly oxidative species being further self-decomplexed to Ni III hydroxides. Our findings suggest that the involvement of Ni IV species might be a viable redox pathway that plays an important role in promoting decomplexation.
研究领域:
环境科学
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化学
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Nano Research
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2023
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IF 9.9
Dong Zhicheng,Xu Yunyun,Wu Can,Chao Jin,Tian Chen,Lin Zhang
Organo-chromium(III) complex is one of the chromium contaminant species, which would transform to high-toxic Cr(VI) during migrating in the environment. Such natural organo-chromium(III) (NOCr) is difficult to remove by traditional degradation or precipitation methods, due to its high stability and solubility. Herein, we demonstrated a novel NOCr removing method by transforming it to certain structures similar to Cr-Fe minerals in nature, through a self-circulating decomplex and immobilization mechanism with nano zero-valent iron (nZVI). Taking chromium glycinate (Cr-Gly) as a probe, nZVI showed a high Cr removal efficiency of 99.4% under ambient conditions. The removal process included three stages of adsorption, decomplexation, and re-immobilization. Cr-Gly was first adsorbed on the surface of nZVI by chemisorption of the oxide shell. Then, the adsorbed Cr-Gly was decomplexed and oxidized to Cr(VI) by ·OH and 1 O 2 , which were generated from molecular oxygen activated by nZVI. Meanwhile, the released Cr(VI) could be in-situ adsorbed and re-reduced to Cr(III), which was further immobilized in form of Cr-O-Fe complex. As the Cr-O-Fe complexing structure was similar to that of Cr-Fe minerals (such as chromohercynite) in nature, this work explored a novel and efficient NOCr removing method that was potential to weaken chromium pollution in the environment.
研究领域:
环境科学
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材料科学
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ACS ES&T Water
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2023
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IF 5.3
Shangying Li,Renji Zheng,Yuanhao Zhou,Shimao Deng,Siyuan Luo,Ranhao Wang,Xuezhen Feng,Hong Chen
Heavy metal–organic complexes widely distributed in wastewater are hazardous and urgently need to be removed and recycled. Herein, copper glycinate (CuGly) was employed as a model complex and removed with the environmentally friendly oxidant ferrate(VI) (Fe(VI)). We found that Fe(VI) can be used to effectively remove CuGly and recycle Cu via a decomplexation–degradation–immobilization coupled pathway, i.e., decomplexing CuGly, degrading organic ligands, and immobilizing the released Cu ions. Theoretical calculation results revealed that CuGly was favored to be oxidized by Fe(VI), and the CuGly decomplexation and organic ligand degradation could spontaneously thermodynamically proceed at room temperature. Although different active oxidation species, including Fe(V), Fe(IV), H2O2, and •OH, are present during the Fe(VI) decomposition process, control experiments suggested that Fe(VI), Fe(V), and Fe(IV), rather than H2O2 and •OH, played critical roles in CuGly removal. The resultant Fe and Cu precipitate could be further converted to a magnetic composite material, which could be used as a catalyst for antibiotic degradation. This study presents an effective strategy and the comprehensive underlying mechanisms of synergistic heavy metal–organic complex removal and metal resource recycling using ferrate, which could be extended to green chemical treatment of heavy metal–organic complexes in various wastewater bodies.
研究领域:
环境科学
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化学工程
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水处理
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高影响因子
Frontiers in Environmental Science
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2022
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IF 5.411
Ma Yameng,Huang Xiao,Han Qi,Yu Jianghua,Yu Fengjiao,Zhu Jia
The strong stability of Cu–ethylenediaminetetraacetic acid (Cu–EDTA) results in the low decomplexation efficiency by the traditional Fenton process. For breaking this limitation, a three-dimensional electro-Fenton (3D-EF) system was constructed to study the decomplexation of Cu–EDTA at different pH, and the effects of Fe2+ concentration, particle electrode dosage, current density, and coexisting ions on decomplexation performance were investigated. The results showed that 3D-EF exhibited high pollutant removal efficiency in a wide pH range compared with the traditional electro-Fenton process. The optimal conditions for the removal of Cu–EDTA were as follows: the pH was 7, Fe2+ was 1 mmol L−1, granular activated carbon was 2 g L−1, and current density was 10 mA cm−2, and the optimum Cu–EDTA removal efficiency reached 90.95%. In addition, the presence of Cl− slightly improved the decomplexation efficiency, whereas NO3− and HPO42− inhibited the removal of Cu–EDTA. The kinetics of Cu–EDTA decomplexation in all experimental groups followed the first-order kinetic equation.
研究领域:
环境工程
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化学工程
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水处理
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
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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
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纳米技术
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PubMed
高影响因子
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