Without extra adjustment of pH, the effects of cupric ions (Cu(II)) and hydrogen peroxide (H2O2) alone or in combination on sludge dewatering were studied. It showed good dewatering capability after ...treated by Cu(II) and Cu(II)/H2O2, which indicated by the capillary suction times (CST) decreased from 120.8 ± 4.7 s (control) to about 40 s, and the water content (Wc) of sludge cake dropped by about 10%. The results showed that the extracellular polymeric substances (EPS) were destroyed, which characterized by a significant decrease in the biopolymers’ concentrations in tightly-bound EPS. Meanwhile, more rough and porous microstructures and higher zeta potentials were obtained after conditioned. Based on the changes of physicochemical properties of sludge, the variations of EPS, and the identification of reactive species, two distinct mechanisms of improved sludge dewatering were postulated. As for Cu(II) treatment, it was mainly due to the surface charge neutralization, strong cytotoxicity of Cu(I) produced by intracellular reduction of Cu(II), and pH decline caused by Cu(II) hydrolysis that improved sludge dewatering performance, which could be noted as a “non-radical pathway”. When in combination with H2O2, hydroxyl radicals (·OH) produced by Cu(II)-catalyzed Fenton-like process played a dominant role in degrading sludge flocs and EPS, which could be regarded as a “radical pathway”.
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•Both Cu(II) and Cu(II)/H2O2 treatment can improve dewaterability of sludge.•The two processes resulted in CST reduction of about 69%.•Cu(I) facilitated sludge dewatering in the Cu(II) treatment.•Hydroxyl radicals play a major role in sludge dewatering by Cu(II)/H2O2 process.
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•Recycling BHC to prepare formed adsorbent by introducing SA and TE.•Constructing slit structures to selectively adsorb planar hydrated copper ions.•Revealing the mechanism on ...synthezing collagen-based aerogel materials.
In this study, (SA/BHC)@TE aerogel is successfully prepared based on hydrogen bonding between three components, covalent cross-linking between bovine hide collagen (BHC) and tannin extract (TE), and the gelation of sodium alginate (SA). The adsorption properties of (SA/BHC)@TE on Cu(Ⅱ) are systematically analyzed through a combination of simulations and specific experiments. Firstly, DFT simulations are performed to rapidly predict the possibility of interactions among BHC, SA and TE. Then, experiments are performed to indicate that the (SA/BHC)@TE aerogel is endowed with a core–shell structure, a slit-shaped pore structure, and abundant active centers (–OH, –COOH, –NH2 and –CONH–). (SA/BHC)@TE has a maximum removal efficiency of 90.3 % for Cu(Ⅱ). Consequently, (SA/BHC)@TE successfully achieves selective adsorption of specific ions Cu(Ⅱ) from the mixture with a distribution coefficient of 11.12 L/g. It suggests that the adsorption is mainly multilayer adsorption and chemisorption. Furthermore, the FTIR and XPS studies reveal that the adsorption of Cu(Ⅱ) onto (SA/BHC)@TE is the result of the synergistic effect of coordination, ion exchange and electrostatic interaction. In addition, the (SA/BHC)@TE aerogel is easy to separate and recycle. Therefore, this paper has important implications for the development of selective adsorbents for Cu(Ⅱ) as well as for the resource utilization of collagen.
•Square planar CuL2 complex exhibited promising cytotoxic activity against extremely aggressive breast cancer cells (MDA-MB-231).•Square planar CuL2 bound perfectly at the groove of DNA through ...hydrogen bonding, hydrophobic and Van der Waals interactions.
A copper(II) complex (CuL2) containing bidentate N,S-donor Schiff base ligands (S-benzyl-β-N-(2-methoxybenzylmethylene) dithiocarbazate, HL) was synthesised and characterised using physicochemical and spectroscopic methods. This work comprehensively includes the single crystal X-ray diffraction analysis of HL, revealing that the centroid of the phenyl ring was engaged in the intermolecular CH interactions that stabilised the three-dimensional (3D) molecular structure. The Hirshfeld surface analysis was used to measure the intermolecular interactions of HL. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations of HL and CuL2 were carried out using B3LYP with the LanL2DZ pseudopotential and 6–311G(d, p) basis set for all the other atoms. The selected calculated frequencies (v(C = N), v(NN), v(C = S)) correlated well with the experimental data obtained, except v(NH). Due to the intra- and intermolecular hydrogen bondings between molecules in solid, some deviation of this band was observed in the calculated gas phase system. The calculated structures and UV–vis results also concur with the experimental findings. It was discovered through cytotoxicity studies that CuL2 had promised good activity against extremely aggressive breast cancer cells (MDA-MB-231). In order to investigate the interactions between cytoactive CuL2 and calf thymus-DNA (DNA), electronic absorption titrations were performed, which revealed moderate binding through groove binding mode with a binding constant (Kb) of 1.75 × 105 M−1. Additionally, the binding capacity of CuL2 with DNA was investigated using molecular docking simulations. The results are comparable with the experimental data, in which CuL2 is bound to the DNA groove via hydrogen bonds and hydrophobic interactions. DNA binding studies have shown that sulfur, nitrogen, and aromatic rings is very important, in terms of the interactions between the lone pairs and π-aromatic ring with nucleobases of DNA.
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Reaction of Zn(II) and Cu(II) bromide and chloride with 2-(aminomethyl)aniline produced a family of 4-, 5- and 6-coordinate complexes. All zinc compounds exhibit monodentate coordination through the ...aminomethyl group, while the copper complexes exhibit chelation of the 2-(aminomethyl)aniline.
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The syntheses and structures of 2-(aminomethyl)aniline (2-AMAn) complexes of CuX2 and ZnX2 (X = Cl, Br) are reported: (2-AMAn)ZnCl2 (1), (2-AMAn)ZnBr2 (2), (2-AMAn)2ZnCl2 (3), (2-AMAn)2ZnBr2 (4), (2-AMAn)2CuClCl (5) and (2-AMAn)2Cu(H2O)2Br2 (6). Compounds 1 and 2 are isomorphous and crystallize in the monoclinic space group Ia with two coordinated halide ions and one chelating 2-AMAn ligand. Compounds 3 and 4 are also isomorphous and crystallize in the monoclinic space group P21/n with two monodentate 2-AMAn ligands and two coordinated halide ions. All four Zn(II) complexes are slightly distorted tetrahedral in geometry. The Cu(II) complexes are structurally distinct from the Zn(II) complexes. 5 crystallizes in the monoclinic space group P21/n and is strongly distorted square pyramidal in geometry with two chelating 2-AMAn ligands, one coordinated chloride ion and one dissociated chloride ion. The bromide compound, 6, crystallizes in the monoclinic space group P21/c, also with two chelating 2-AMAn ligands, but with two coordinated water molecules and both bromide ions dissociated in the lattice.
Cu(II)-
β
-cyclodextrin-catalyzed synthesis of spiroindoline-3,4′-pyrano3,2-cchromene-3′-carbonitriles through the reaction of isatin derivatives, 4-hydroxycoumarin, and malononitrile in ethanol at ...room temperature.
A novel nano‐ternary spinel oxides of Zn−Ni‐Co−O are synthesized via the coprecipitation method and used for detection towards Cu(II). The Zn doping effect on morphologies and microstructures of ...ZnxNi1‐xCo2O4 (x=0, 0.2, 0.4, 0.6, 0.8, 1.0) is systematically characterized and investigated. At the x of 0.4, the prepared Zn0.4Ni0.6Co2O4 modified electrode nanomaterials can realize electrochemical ultratrace detection of Cu(II), which shows the lowest detection limit of 1.96 nM with a linear range of 0.1 μM∼1.0 μM and the highest sensitivity of 15.2 μA/μM. Meanwhile, Zn0.4Ni0.6Co2O4 modified electrodes exhibit excellent repeatability (relative standard deviation (RSD) of 0.34 %), reproducibility (RSD of 0.3 %), stability (RSD of 3.0 %) as well as anti‐interference analysis, which has been successfully applied in the actual water environment. These results indicate that ZnxNi1‐xCo2O4 nanoparticles as a promising modified electrode materials for the electrochemical detection Cu(II).
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•First study on recycling Cu(II) in complexing copper wastewater by CMC-FeS.•CMC-FeS is a promising strategy to treat complexing copper wastewater.•The stability of FeS and the ...recycling Cu(II) in wastewater have been addressed.•Precipitation, replacement, adsorption, and flocculation are dominant mechanisms.
Investigating the Cu(II) recovery rate in complexing copper wastewater holds significant importance in achieving resource recycling and enhancing the sustainability of industrial processes. In this study, the ferrous sulfide stabilized by carboxymethyl cellulose (CMC-FeS) was synthesized as a promising strategy to treat complexing copper wastewater, which addressed issues of the stability of FeS nanoparticles and recycling Cu(II) from complexing copper wastewater. Experimentally, the Cu(II) recovery rate was found to be 99.8 % from cupric tartrate (Cu-TA) solutions (Cu(II) = 640 mg/L), as well as the Cu(II) recovery rate reached up to 99.9 % from micro-etching copper-containing wastewater (Cu(II) = 6276.65 mg/L), when treated by CMC-FeS with the molar ratio of FeS/Cu = 1.25. The underlying mechanism has been systematically elucidated through chemical equilibriums, FTIR/Raman spectral analysis, SEM-EDS analysis, and XPS analysis, providing a solid foundation for further development and application. CMC-FeS can effectively compete with Cu(II) ligands to recover Cu(II) from copper complex wastewater, which is an efficient countermeasure for the treatment of copper complex wastewater. This process involves a variety of mechanisms, such as sulfide precipitation, replacement or ion exchange, complex adsorption, and flocculating sedimentation, finally produces insoluble precipitates with CuS as the main component. This study provides a valuable reference for the treatment of heavy metal complex wastewater, especially the recycling and utilizing metal resources.
In this study, a convenient method for the synthesis of arylaminotetrazoles has been developed using a copper (II)-aminotetrazole complex immobilized on silica-coated Fe3O4 (Fe3O4@SiO2) nanoparticles ...(Fe3O4@SiO2-aminotet-Cu(II)) as a novel and efficient magnetically catalyst. The constructed superparamagnetic core-shell nanoparticles were successfully prepared, as proven using different spectroscopic techniques such as fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetry and differential thermogravimetry (TG-DTG) and vibrating sample magnetometer (VSM) analysis. The applicability of Fe3O4@SiO2-aminotet-Cu(II) magnetic catalyst allows the efficient synthesis of a variety of arylaminotetrazoles from the reaction between various arylcyanamides with sodium azide in high yields. The effect of catalyst loading was investigated. In addition, the reaction mechanism for the synthesis of arylaminotetrazoles was reasonably proposed. Results show that the 1-aryl-5-amino-1H-tetrazole (B isomer) and 5-arylamino-1H-tetrazole (A isomer) can be obtained from the arylcyanamides carrying electron-donating and electron-withdrawing substituents, respectively. This procedure offers a simple methodology, relatively short reaction times, easy work-up, high yields of the products and a cleaner reaction with elimination of hydrazoic acid (HN3). Moreover, catalyst can be conveniently recovered through the use of external magnet and reused for at least 6 times without any significant loss of its activity.
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•Efficient synthesis of the Fe3O4@SiO2-aminotet-Cu(II) catalyst.•Synthesis of arylaminotetrazoles using Fe3O4@SiO2-aminotet-Cu(II) as a reusable catalyst.•Characterization of the catalyst using TG-DTG, FT-IR, TEM, FESEM, VSM, XRD, EDS analyses.
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•One-pot method to prepare calixarene adsorbent by electron beam irradiation.•TC4A/PAA/diatomite irradiated at 90 kGy has high efficient for Cu(II) adsorption.•The maximum adsorption ...capacity of TC4A/PAA/diatomite (90 kGy) for Cu(II) is 123.30 mg/g.•The microstructure and adsorption performance of TC4A/PAA/diatomite were studied.
Chemical grafting of calix4arene is a common method to prepare high-performance calix4arene adsorbents for heavy metals, however, the chemical grafting process consumes much time and a large amount of heating energy due to the tedious steps. Herein, a thiacalix4arene/acrylic polymer/diatomite (TC4A/PAA/diatomite) adsorbent was fast fabricated by electron beam irradiation induced grafting, polymerization and crosslinking technique only in one-pot for the removal of Cu(II) as an important form of heavy metal pollution. Characterization by Fourier transform infrared (FTIR) spectra, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), diffuse reflectance UV–visible spectra and positron annihilation lifetime spectra (PALS) disclosed that the eco-friendly and low-cost TC4A/PAA/diatomite irradiated at 90 kGy namely TC4A/PAA/diatomite (90 kGy) with strong complexing ability owing to many functional groups such as carboxyl, hydroxyl etc in it. The effects of electron beam irradiation dose, initial solution pH, and initial concentration of Cu(II) on the adsorption performance of TC4A/PAA/diatomite were investigated. The isotherm adsorption data of Cu(II) in TC4A/PAA/diatomite (90 kGy) are more suitable for the Langmuir model with the maximum adsorption capacity of 123.30 mg/g. In addition, the bifunctional TC4A/PAA/diatomite (90 k Gy) can efficiently remove Cu(II) and display excellent reusability properties. The adsorption mechanism was further analyzed by FTIR, SEM, X-ray photoelelctron spectroscopy (XPS), diffuse reflectance UV–visible spectra and PALS. This study provides a fast, efficient and eco-friendly synthesis method of calix4arene adsorbent, conducing to the design of material innovation. Meanwhile, TC4A/PAA/diatomite (90 kGy) has potential application prospects in the treatment of practical Cu(II) contaminated wastewater.
