查找使用阿拉丁产品的科研文献

A novel polyamine-type starch/glycidyl methacrylate copolymer for adsorption of Pb(II), Cu(II), Cd(II) and Cr(III) ions from aqueous solutions

Youning Chen,Wei Zhao,Huan Wang,Xiaohua Meng,Linjie Zhang

A novel polyamine-type starch/glycidyl methacrylate (GMA) copolymer with a high capacity for the adsorption of heavy metal ions was prepared via graft copolymerization of GMA and corn starch and a subsequent amination reaction between amino group of diethylenetriamine and epoxy group in GMA. The copolymers were characterized by Fourier transform infrared spectrometry, X-ray diffraction and scanning electron microscopy, and adsorption properties on modified starch of Cu(II), Pb(II), Cd(II) and Cr(III) were studied. By analysing the relationship between adsorption capacity and pH, adsorption isotherms and adsorption kinetics, it is proved that the adsorption of the four metal ions is mainly based on the chemical adsorption of coordination. The maximum adsorption capacities of the copolymer were up to 2.33, 1.25, 0.83 and 0.56 mmol g−1 for Cu(II), Pb(II), Cd(II) and Cr(III), respectively. The adsorption of the four concerned metal ions was hardly affected by common coexisting ions such as Na(I), K(I), Ca(II) and Mg(II), whereas it was slightly decreased when Fe(II) and Zn(II) coexisted in the solution, which illustrates the selective adsorption of Cu(II), Pb(II), Cd(II) and Cr(III) from wastewater. After 10 cycles of adsorption–desorption experiments, there was no significant change in the adsorption capacity, indicating that the polyamine-type starch/GMA copolymer has high adsorption capacity and good reusability.

Zeolite-supported nanoscale zero-valent iron: New findings on simultaneous adsorption of Cd(II), Pb(II), and As(III) in aqueous solution and soil

Zhangtao Li,Lu Wang,Jun Meng,Xingmei Liu,Jianming Xu,Fan Wang,Philip Brookes

Nanoscale zero-valent iron (NZVI) has a high adsorption capacity for heavy metals, but it forms aggregates easily. In this study, zeolite-supported nanoscale zero-valent iron (Z-NZVI) was synthesized from a simplified liquid-phase reduction of iron(III) salts which simultaneously adsorbed As(III), Cd(II) and Pb(II) from aqueous solution and soil. Scanning electron micrographs showed that aggregation was eliminated and the NZVI evenly dispersed onto the surface of zeolite. FTIR spectra reveal that NZVI was protected from oxidization on the surface of Z-NZVI. XRD and XPS patterns confirmed the formation of Cd(OH) 2 , Pb 0 , and FeAsO 4 in Z-NZVI after adsorption. The experimental maximum adsorption capacity of Z-NZVI was 11.52   mg As(III)/g, 48.63   mg Cd(II)/g, and 85.37   mg Pb(II)/g at pH 6, respectively, much higher than that of zeolite. Batch experiments indicate that various adsorption mechanisms including electrostatic adsorption, ionic exchange, oxidation, reduction, co-precipitation, and complexation coexisted with the selected heavy metals. Due to the formation of multiphase compounds on the Z-NZVI, the synergy and competition among heavy metals were concurrent. Most arsenic, cadmium and lead in the soil samples were immobilized after mixing with 30   g/kg Z-NZVI. These results suggest that Z-NZVI has great potential for treating water and soil multi-contaminated with heavy metals.

Synthesis of a tetrazine-based catecholamide derivative and its evaluation as a chelating agent for removal of Cd(II), Co(II), and Cu(II)

Shan Lei,Bo Jin,Rufang Peng,Qingchun Zhang,Shijin Chu

Imidazole functionalized organic monoliths for capillary microextraction of Co(II), Ni(II) and Cd(II) from urine prior to on-line ICP-MS detection

Liu Xiaolan,Suo Feiya,He Man,Chen Beibei,Hu Bin

Monoliths composed of poly(1-vinylimidazole-ethylene glycol dimethacrylate), referred to as poly(VI-EGDMA), were modified with imidazole groups and used in capillary microextraction (CME) of trace levels of Co(II), Ni(II) and Cd(II) ions from human urine samples. The effects of sample pH, sample flow rate, sample volume, elution conditions and potentially interfering ions were investigated. Under the optimized conditions, the limits of detection (3σ) are 0.6 ng L −1 for Co(II), 6.4 ng L −1 for Ni(II) and 0.7 ng L −1 for Cd(II), with the relative standard deviations of 1.8 (Co), 4.2 (Ni) and 2.2% (Cd). A Certified Reference Material (ZK018–2, lyophilized human urine) was analyzed to validate the method, and the values found were in good agreement with the certified ones. The method was successfully applied to the analysis of trace Co, Ni and Cd in human urine samples, and the recoveries for spiked samples were in the range from 89% to 105%. The one-step preparation of monolithic material in our perception is an attractive feature for this material which also excels by good extraction performance in that it possesses abundant adsorption sites, good stability and a long lifetime. Two poly(1-vinylimidazole-ethylene glycol dimethacrylate) monolithic capillaries were combined with ICP-MS to improve the analytical speed and used for the analysis of Co(II), Ni(II) and Cd(II) in human urine samples.

Simultaneous detection of Cd(II) and Pb(II) by differential pulse anodic stripping voltammetry at a nitrogen-doped microporous carbon/Nafion/bismuth-film electrode

Lili Xiao,Hongbo Xu,Shenghai Zhou,Ting Song,Huanhuan Wang,Shouzhu Li,Wei Gan,Qunhui Yuan

Recently, metal-organic frameworks (MOFs) and their carbon derivates have been demonstrated as new electrode modifying materials for electrochemical sensing. In this work, the first example of the detection of heavy metal ions with a MOF-derived sensing platform was presented. The platform was based on a glassy carbon electrode (GCE) modified by Nafion-bismuth/nitrogen doped microporous carbon (NMC) composite, in which the NMC was derived from a zeolitic imidazolate framework-8 (ZIF-8). The good dispersibility, large specific surface area (941 m 2   g −1 ), high nitrogen content (25.0 at.%) and good electrical conductivity of the NMC materials, as well as the synergistic effects of Nafion and bismuth-film contributed to the enhanced signals of the electrode during the differential pulse anodic stripping voltammetry (DPASV) measurements for simultaneous detection of trace Cd(II) and Pb(II) in aqueous solution. The calibration curves for Cd(II) covered two linear ranges varying from 2 to 10   μg   L −1 and 10 to 100   μg   L −1 . As for Pb(II), the linear calibration curves ranged from 0.5 to 10   μg   L −1 and 10 to 100   μg   L −1 . The detection limits were estimated to be 1.5   μg   L −1 (S/N   =   3) for Cd(II) and 0.05   μg   L −1 (S/N   =   3) for Pb(II), which were 2 times and 200 times lower than the guideline values of drinking water given by the World Health Organization (WHO), for Cd(II) and Pb(II), respectively. In addition, the good reproducibility and stability of the modified electrode offered a promising perspective for the detection of trace metal ions in practice. Compared with other porous carbon modified electrodes that obtained by either drop-casting or screen-printing method, the proposed Nafion/Bi/NMC/GCE showed a much lower detection limit for Pb(II) and a lower or comparable detection limit for Cd(II). Moreover, the obtaining of uniformly ordered N-doped carbon polyhedron could shed light on the preparation of other heteroatom-doped electrode modifying materials for the detection of heavy metal ions .

Comparison Studies on Several Ligands Used in Determination of Cd(II) in Rice by Flame Atomic Absorption Spectrometry after Ultrasound-Assisted Dispersive Liquid–Liquid Microextraction

Qian Sun,Xinyu Cui,Yanfeng Wang,Pingping Zhang,Wenjuan Lu

Ligands plays an important role in the extraction procedures for the determination of cadmium in rice samples by using flame atomic absorption spectrometry (FAAS). In the present study, comparative evaluation of 10 commercially available ligands for formation of Cd(II)-ligand complex and determination of cadmium in rice samples by ultrasound-assisted dispersive liquid–liquid microextraction (UADLLME) combined with FAAS was developed. Sodium diethyldithiocarbamate (DDTC) provided a high distribution coefficient as well as a good absorbance signal, therefore DDTC was used as a ligand in UADLLME. A low density and less toxic solvent, 1-heptanol, was used as the extraction solvent and ethanol was used as the disperser solvent. In addition, the experimental conditions of UADLLME were optimized in standard solution first and then applied in rice, such as the type and volume of extractant and dispersant, pH, extraction time, and temperature. Under the optimal experimental conditions, the detection limit (3σ) was 0.69 μg/L for Cd(II). The proposed method was applied for the determination of Cd(II) in three different rice samples (polished rice, brown rice, and glutinous rice), the recovery test was carried out, and the results ranged between 96.7 to 113.6%. The proposed method has the advantages of simplicity, low cost, and accurate and was successfully applied to analyze Cd(II) in rice.Keywords:ligands;rice;cadmium;dispersive liquid-liquid microextraction;flame atomic absorption spectrometry

Zn(II), Cd(II), Mn(II), and Cu(II) complexes based on an imidazole derivative and carboxylic acids: synthesis, crystal structures, and DNA-binding properties

Ying Zhou,Xiao-Tong Song,Hui-Chao Guan,Shu-Mei Yue

In this investigation, six new metal complexes with 2-(pyridin-2-yl)benzo[d]imidazole (bpm) were synthesized and analyzed by single-crystal X-ray diffraction (XRD), including catena-bis[(µ-2,2-bis(4-carobxyphenyl)hexafluoropropane)-(2-(pyidin-2-yl)-1H-benzimidazole)-aqua-zinc] (1), catena-[(µ-2,2-bis(4-carobxyphenyl)hexafluoropropane)-(2-(pyidin-2-yl)-1H-benzimidazole)-aqua-cadmium] (2), aqua-[2,2-bis(4-carobxyphenyl)hexafluoropropane]-bis[2-(pyridin-2-yl)-1H-benzimidazole]-manganese (3), μ-[2-nitrobenzene-1,4-dicarboxylato]-μ-[2-nitrobenzene-1,4-dicarboxylato]-bis[2-(pyridin-2-yl)-1H-benzimidazole]-di-zinc (4), catena-[bis(µ-2-nitrobenzene-1,4-dicarboxylato)-diaqua-bis(2-(pyridin-2-yl)-1H-benzimidazole)-di-cadmium] (5), aqua-[pyridine-2,6-dicarboxylato]-[2-(pyridin-2-yl)-1H-benzimidazole]-copper hydrate (6) (H2hfipbb = 2,2-bis(4-carboxyphenyl)hexafluoropropane, H2nbdc acid = Nitroterephthalic acid, and H2pda = 2,6-pyridinedicarboxylic acid). Complex 1 crystallized in a monoclinic system with space group P21/n; 2 crystallized in a monoclinic system with space group C2/c; 3 crystallized in an orthorhombic system with space group Pna21; 5 crystallized in a monoclinic system with space group P21/c; 4 and 6 crystallized in triclinic systems with space group P-1. The DNA-binding modes of the complexes were investigated by several analysis methods (e.g. viscosity analysis, circular dichroism spectroscopy, fluorescent spectroscopic analysis, as well as UV spectroscopic analysis). Complexes 1-6 bind to calf thymus DNA via an intercalative mode. The results of this study provide insights into the mechanism of DNA binding and provide a basis for rationally designing new powerful reagents for DNA detection and targeting.

Water-stable mixed-ligand Cd(II) metal-organic frameworks as bis-color excited fluorescent sensors for the detection of vitamins and pesticides in aqueous solutions

Zi-Ping Wang,Yu Wang,Xin-Yu Li,Lin-Fang Jia,Ai-Zhen Yang,Wen-Ting Zhao,Yi Jia,Bao-Yi Yu,Han-Qing Zhao

The synthesis and characterization of three 2D to 3D metal-organic frameworks (MOFs) with mixed ligands, namely {[Cd(DINT)(TPA)(H 2 O)]ACN} n (BAO24) (H 2 TPA = tere phthalic acid, DINT = 1,4-di(imidazol-1-yl)naphthalene, and ACN = acetonitrile), {[Cd(DINT)(IPA)]DMF} n (BAO25) (H 2 IPA = iso phthalic acid and DMF = N,N -dimethylformamide), and [Cd(DINT)(PA)] n (BAO26) (H 2 PA = phthalic acid), were reported herein. The structures and purities of the MOFs were revealed and confirmed by single-crystal X-Ray diffraction, Fourier transform infrared spectroscopy, powder X-Ray diffraction, thermogravimetric analysis, and elemental analysis. The MOFs exhibited a fluorescence emission peak around λ em = 340 nm with relative excitation wavelengths at both 230 and 290 nm. Since the MOFs showed similar fluorescence properties, BAO24 was selected as a representative MOF in the fluorescent sensing processes. The result showed that BAO24 exhibited a high sensitivity for vitamin B2. However, when sensing pesticides, the sensor performed differently at each excitation wavelength. At λ ex = 230 nm, the sensor was quenched the most significantly with the nitenpyram analyte, while at λ ex = 290 nm, the highest fluorescence quenching was achieved by the imidacloprid analyte.

Synergistic valorization of red mud and spent coffee grounds via one-step hydrothermal carbonization for high-efficiency Pb(II) and Cd(II) removal from wastewater

Yuting Cui,Yue Zhou,Mingqian Cheng,Wei Fang,Yaoling Wang,Chao Chen,Tingting Liu,Bin Li,Zewei Liu

The escalating contamination of water resources by toxic heavy metals necessitates sustainable remediation strategies. This study presents a novel adsorbent, RHC-180/0.5, synthesized via a one-step hydrothermal carbonization under mild conditions, utilizing red mud (RM) and spent coffee grounds (SCG) as raw materials. The biopolymers in SCG, including cellulose, hemicellulose, and lignin, transformed into hydroxyl, carboxyl, and phenolic groups, enhancing the material's adsorption capacity. Batch adsorption experiments showed optimal performance under alkaline conditions. To minimize precipitation interference, the adsorption mechanism was further investigated at pH = 6. Pseudo-second-order kinetics and Freundlich isotherm models indicated chemical adsorption and heterogeneous multilayer adsorption, respectively. Simultaneously, the Langmuir model yielded maximum theoretical adsorption capacities of 302.33 mg/g and 154.97 mg/g for Pb(II) and Cd(II), respectively, confirming the excellent adsorption performance of RHC-180/0.5. Intraparticle diffusion model analysis showed that surface diffusion dominated in the three-phase adsorption process. Thermodynamic analysis confirmed that the adsorption process was endothermic. Spectroscopic analysis validated the roles of chemical precipitation, ion exchange, and cation-π interactions, surface complexation, and redox reactions in the adsorption mechanism. At pH = 6, RHC-180/0.5 retained approximately 80 % of its initial removal efficiency after ten regeneration cycles, demonstrating excellent stability and reusability. This work highlights a sustainable, cost-effective approach to converting agricultural and industrial waste into high-performance adsorbents for heavy metal-contaminated wastewater treatment.

Synthesis, crystal structures and DNA-binding properties of Zn(II), Cd(II), Mn(II), Cu(II) complexes based on a thiazole derivative and carboxylic acids

Xiao-Tong Song,Ying Zhou,Gui-Bao Liu,Hui-Chao Guan,Shu-Mei Yue

By single-crystal X-ray diffraction (XRD) analysis, five complexes, catena-[(µ-2,2-bis(4-carboxyphenyl)hexafluoropropane)-(2-(pyidin-2-yl)-1,3-benzothiazole)-aqua-zinc(II)] (1), catena-[(µ-2,2-bis(4-carboxyphenyl)hexafluoropropane)-(2-(pyidin-2-yl)1,3-benzothiazole)-aqua-cadmium(II)] (2), catena-[hepta(µ-2,2-bis(4carboxyphenyl)hexafluoropropane)-diaqua-bis(2-(pyidin-2-yl)-1,3-benzothiazole)-tri-manganes(II)] (3), catena-[(µ-benzene-1,2,4,5-tetracarboxylato)-(2-(pyidin-2-yl)-1,3benzothiazole)copper(II)] (4) and catena-[(µ-3-nitrobenzene-1,2-dicarboxylato)-(2-(pyidin-2-yl)1,3-benzothiazole)-aqua-zinc(II)] (5), were characterized in this research. In these five complexes, H2hfipbb = 2,2-bis(4-carboxyphenyl)hexafluoropropane, H4btec = 1,2,4,5-benzenetetracarboxylic acid, H2NPTA = 3-nitrophthalic acid and bpt = 2-(pyridin-2-yl)benzo[d]thiazole). Complexes 1 and 2 occur in the monoclinic system with space group C2/c, 4 and 5 occur in the monoclinic system with space group P21/c, and 3 occurs in the triclinic system with space group P-1. The interaction between CT-DNA (calf thymus DNA) and those complexes was examined using UV spectroscopic analysis, fluorescent spectroscopic analysis, circular dichroism spectroscopy (CD) and viscosity analysis. This research reveals that those complexes have strong ability to interact with DNA, and they all bind to DNA in an intercalation mode, thus affecting the structure of DNA. This binding mode can arise from the interaction between the benzothiazole metal complexes and DNA. Hence, we hope to provide some scientific research bases for studying benzothiazole complexes and designing new thiazole anticancer drugs.

High performance ratiometric detection towards trace Cd(II) and Pb(II) utilizing in-situ bismuth modified nitrogen rich porous carbon/boron doped diamond composite electrode

Xuesong Zhou,Zhigang Gai,Yibao Wang,Shousheng Liu,Xueyu Zhang,Fengxiang Guo,Mei Zhang,Lili Zhang,Xin Jiang

The high performance detection of heavy metal ions in crucial water sources is of great significance to protect human health and life safety. Herein, a novel ratiometric detection system towards trace Cd(II) and Pb(II) has been established by utilizing in-situ bismuth modified nitrogen rich porous carbon/boron doped diamond (Bi/NC/BDD) composite electrode. Benefiting from the interconnected hierarchical micro/mesoporous structure and N-embedded partially graphitized carbon matrix of NC modifier, as well as the formation of Bi-alloy, an excellent sensitivity with low limit of detection (LOD, 0.24 μg L −1 for Cd(II) and 0.37 μg L −1 for Pb(II)) is realized. Moreover, the built-in normalization function of Bi(III) reference signal effectively improves the reliability and reproducibility of detection results. This work provides an important guidance for the development of quality environmental monitoring electrodes.

Construction of novel maple leaf-like MnO2–SiO2@PDA composites for highly efficient removal of Cu(II), Cd(II) and Ni(II) from aqueous solution

Zhiqiang Guo,Lei Sun,Hui Hou,Jian Zhou,Yuan Li,Liangliang Hu,Jinzhang Xu

The preparation of the maple leaf-like MnO 2 –SiO 2 @PDA biomimetic composites not only overcame the problem of easy agglomeration of nanoparticles, but also provided rich functional groups, large specific surface areas and good stability, achieving the efficient sorption of Cu(II), Cd(II) and Ni(II) from aqueous solution. The maximum sorption capacities of the MnO 2 –SiO 2 @PDA towards Cu(II), Cd(II) and Ni(II) attained from the Langmuir model were 218.788, 383.420 and 148.939 mg·g −1 , respectively. The sorption of Cu(II), Cd(II) and Ni(II) on the MnO 2 –SiO 2 @PDA were strongly affected by pH, but not by ionic strength, showing good resistance to salt interference. The main sorption mechanism of the MnO 2 –SiO 2 @PDA towards Cu(II), Cd(II) and Ni(II) was the strong surface complexation of the functional groups on the MnO 2 –SiO 2 @PDA with Cu(II), Cd(II) and Ni(II). Moreover, the radii of Cu(II), Cd(II) and Ni(II) ions and their complexation strength with the MnO 2 –SiO 2 @PDA jointly determined the order of the competitive sorption capacities as Cu(II) > Cd(II) > Ni(II). Given the above analyses, the maple leaf-like MnO 2 –SiO 2 @PDA biomimetic composites have excellent application prospects in practical wastewater treatment.