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.

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 .

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.

Enhancement of Oryzanol application by constructing modified β-CD inclusion complex and polycaprolactone-chitosan electrospun fiber membranes: Perspectives on wound dressings and grape preservation

Wen Li,Jintao He,Qijue Chen,Feng Bao,Yinqiang Huo,Jing Deng,Qinlu Lin,Feijun Luo

Oryzanol has a variety of physiological activities and is widely used in food and medicine. However, its utilization form and bioavailability are limited by poor solubility and photothermal stability. In this paper, an inclusion complex (IC) was prepared by modifying β-cyclodextrin as a molecular carrier to encapsulate Oryzanol. Polycaprolactone-chitosan (PCL-CS) and IC were prepared into a fiber membrane (PCL-CS-IC) using an electrostatic spinning technique and applied to wound healing and grape preservation. The results showed that the prepared ICs had a drug loading rate of 43.18 % with good antimicrobial, wettability, and air permeability properties. The PCL-CS-IC effectively reduced the inflammation of mouse wounds, with obvious re-epithelialization and inflammatory factors reduction in skin tissues. Meanwhile, the PCL-CS-IC delayed the decay process of grapes and extended shelf life. In conclusion, this study effectively improved the utilization of oryzanol and provided potential ideas for wound dressing preparation and food packaging materials development.

De novo synthesis of α-Alk-β-CD: An organic–inorganic hybrid chiral stationary phase for enhanced enantioseparation efficiency and its recognition mechanism research

Jianbin Zhang,Qiufang Bai,Mei Han,Xizhe Sun,Feixue Zhou,Xin Fang,Yuran Shi,Hongna Wang,Yaowen Zhang,Linwei Li,Linlin Fang

Herein, two highly stable β -CD and α-Alkenyl- β -CD ( α -Alk- β -CD) monolithic columns were fabricated by copolymerizing β -CD and α -Alk- β -CD with GMA onto the pretreated capillary by a simple one-pot strategy. 1 H NMR, SEM, FT-IR, TGA and BET surface area analyses were applied to characterize the prepared monolithic columns. The monoliths were evaluated on the enantioseparations of antibiotic drugs, antihistamine drugs, anticholinergic agents, antifungal drugs and pesticides. In contrast to the native β -CD monolith, the derived α -Alk- β -CD reveals significantly improved enantiodiscrimination performance for the analytes especially for pesticides. Through run-to-run (n = 6), day-to-day (n = 9), and column-to-column (n = 9) investigations, the RSDs values were all lower than 3.72 %. Molecular simulation reveled that the chiral recognition between α -Alk- β -CD and chiral drugs was an exothermic process mainly governed by interaction hydrogen bindings, resulting in different binding strength between a pair of isomers compounds and α -Alkenyl- β -CD, and then leading to different migration and finally achieving effective chiral separation.

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.

Mn-embedded biochar for enhanced removal of Cd(II), Pb(II) and Ni(II): Physicochemical properties, high-efficiency adsorption capacities and quantitative mechanism analysis

Yipeng Wang,Kun Wang,Xuchan Wang,Qingliang Zhao,Junqiu Jiang,Ruiyuan Xue,Luzi Yuan

Heavy metals (HMs) in wastewater, including Cd, Pb and Ni, were toxic and needed urgent treatment. Using biochar as an adsorbent to purify HM-containing wastewater is effective. However, there are few studies on screening of high-efficiency modifier and comparing their adsorption capacity. Herein, three different modification methods, including heteroatomic doping (urea), alkali hydroxide (NaOH) and chemical oxidation (KMnO 4 ), were used to improve removal ability of HMs by biochar. The difference in impregnation solution resulted in completely differences in microscopic morphology, physicochemical properties and adsorption efficiency of modified biochar. Biochar modified by KMnO 4 (Mn-BC) had significantly better adsorption capacity for Cd, Pb and Ni, reaching 46.40 mg/g, 80.20 mg/g and 18.65 mg/g, respectively, compared with raw biochar and other modification biochar, which might be due to the highest surface area and pore volume, lower zeta potential and loaded MnO x onto Mn-BC surface. Chemical and monolayer adsorption was dominant during adsorption of HMs. After adsorption, HMs were detected on the Mn-BC surface in the form of carbonate, hydroxide or oxide. Mineral precipitation and cation exchange were the dominant mechanisms during adsorption, accounting for 17.4%-41.8% and 43.0%-77.2%, respectively. Moreover, according to the correlation analysis, the increase in biochar pH, pore volume and degrees of carbonization were beneficial for HM adsorption. Mn-BC could adapt to a wider pH range (pH=4–6), and its adsorption capacity would not be interfered by coexisting ions (50 mg/L). This research proved advantages of biochar with KMnO 4 modification and highlighted its application in treatment of wastewater contaminated with multiple HMs.

Easily recoverable Cd x Zn1−x S-Gel photocatalyst with a tunable band structure for efficient and stable H2 production mediated by visible light

Wu Yongli,Gao Jianping,Hao Chaoyue,Mei Shunkang,Yang Jiangbing,Wang Xiaoxue,Zhao Ruiru,Zhai Xiangang,Liu Yu

A photocatalyst consisting of a cellulose hydrogel loaded with Cd x Zn 1− x S (Cd x Zn 1− x S-Gel) was prepared, and its photocatalytic water splitting activity was studied. At room temperature, the Cd x Zn 1− x S particles with an average size of about 3 nm were loaded in carboxymethyl cellulose hydrogel by an in situ chemical reaction. This synthesis method was simple and repeatable. Diffuse reflectance UV–vis results showed that it is possible to adjust the optical properties of the synthesized photocatalysts by adjusting their composition. Under visible light irradiation, the hydrogen production rate of the photocatalysts was greatly improved. In the absence of a co-catalyst, Cd 0.2 Zn 0.8 S-Gel obtained the highest hydrogen production rate of 1762.5 μmol g −1  h −1 , which is almost 104 times of that of the pure CdS. Moreover, after four hydrogen production cycles, the hydrogen production rate did not decrease significantly, showing excellent stability. It is noteworthy that the Cd x Zn 1− x S-Gel can easily be removed from the aqueous solution after hydrogen production. This is a new approach for manufacturing easy recoverable visible-light-driven photocatalysts, which is vital for hydrogen production through a “green” process.

Rapid and Portable Detection of Pb(II) and Cd(II) Ions Using a Screen-Printed Graphene Electrode Enhanced with Alkalized MXene and Gold Nanoparticles

Huajin Tao,Nan Wang,Yitian Ma,Ahua Xu,Baoyu Huang,Xiaogan Li

This study introduces the development of a portable electrochemical sensor for the detection of Pb(II) and Cd(II) ions based on a screen-printed graphene electrode (SPGE) enhanced with alkalized MXene and gold nanoparticles (AuNPs). Experimental results reveal that the Au@Alk-MXene/SPGE electrode exhibits excellent electrical conductivity, enlarged active surface area, and efficient electron transfer capability, which enhances the electrochemical detection of Pb(II) and Cd(II) ions. Under optimal experimental conditions, the sensor demonstrates good electrochemical response and distinct stripping peaks for both ions. The linear detection range of the sensor is 5-130 μg L⁻¹ for both Pb(II) and Cd(II), with detection limits of 0.198 μg L⁻¹ for Pb(II) and 0.106 μg L⁻¹ for Cd(II). Furthermore, the sensor shows excellent repeatability with relative standard deviations (RSDs) of 1.16% (n = 10) for Pb(II) and 1.25% (n = 10) for Cd(II), as well as remarkable reproducibility with RSD values of 1.56% for Pb(II) and 1.57% for Cd(II). The sensor was successfully applied to analyze tap water and lake water samples, demonstrating satisfactory recovery rates. This research shows the use of MXenes and AuNPs to modify SPGE electrodes, offering a rapid and portable electrochemical sensor for detecting Pb(II) and Cd(II) ions in water.

Ratiometric emission of Tb(III)-functionalized Cd-based layered MOFs for portable visual detection of trace amounts of diquat in apples, potatoes and corn

Yin-Xia Sun,Bo-Tao Ji,Jiang-Hai Chen,Lu-Lu Gao,Yu Sun,Zhe-Peng Deng,Biao Zhao,Jin-Guo Li

Diquat (DQ) is a typical bipyridine herbicide widely used to control weeds in fields and orchards. The severe toxicity of diquat poses a serious threat to the environment and human health. Metal-organic frameworks (MOFs) have received widespread attention due to their unique physical and chemical properties and applications in the detection of toxic and harmful substances. In this work, a two-dimensional (2D) Tb(III) functionalized MOF Tb(III)@ 1 ( 1  = [Cd(HTATB)(bimb)] n ·H 2 O (Cd-MOF), H 3 TATB = 4,4′,4″-triazine-2,4,6-tribenzoicacid, bimb = 1,4-bis((1H-imidazol-1-yl)methyl)benzene) has been prepared and characterized. Tb(III)@ 1 has excellent optical properties and high water and chemical stability. After the Tb(III) is fixed by the uncoordinated -COO- in the 1 framework, Tb(III)@ 1 emits the typical green fluorescence of the lanthanide ion Tb(III) through the “antenna effect”. It is worth noting that Tb(III)@ 1 can be used as a dual emission fluorescence chemical sensor for the ratio fluorescence detection of pesticide DQ, exhibiting a relatively low detection limit of 0.06 nM and a wide detection range of 0–50 nM. After the addition of DQ, a rapid color change of Tb(III)@ 1 fluorescence from green to blue was observed due to the combined effects of IFE, FRET and dynamic quenching. Therefore, a simple test paper box has been designed for direct on-site determination of pesticide DQ. In addition, the developed sensor has been successfully applied to the detection of DQ in real samples (fruits a Yin-Xia Sun and Bo-Tao Ji contributed equally to this work and should be considered co-first authors.nd vegetables) with satisfactory results. The results indicate that the probe developed in this study has broad application prospects in both real sample detection and actual on-site testing.

Removal and stabilization of As and Cd in water/soil using silicate-supported nano zero-valent iron composites: Preparation, behavior, mechanism and cost analysis

Qiwei Sun,Huifen Yang,Xiaodi Feng,Tong Zhao

A novel silicate-supported nano zero-valent iron composite material (nZVI@SS) for the removal and stabilization of arsenic (As) and cadmium (Cd) in water/soil had been developed through the modification of low-grade oolitic iron ore (OI) by reduction, while refinery sludge (RS) as reductant, manganese carbonate (MC) as additive in this work. The As and Cd adsorption capacity of nZVI@SS reached 93.91 mg·g −1 and 265.81 mg·g −1 , respectively. Its specific surface area and pore volume increased by 19.28 m 2 ·g −1 and 0.24 cm 3 ·g −1 , respectively when compared with unmodified OI. In the actual soil leaching process, using 2 % nZVI@SS for 30 days, the leaching concentrations of As and Cd decreased by 87.86 % and 85.51 % respectively, while their bioavailable contents were reduced by 15.59 mg·kg −1 and 1.40 mg·kg −1 , correspondingly. The formation of chemical precipitates as Fe-As, Ca-As compounds, and Cd(OH) 2 was the main mechanism of their adsorption process . Therefore, HMs adsorbed by nZVI@SS were difficult to desorb, making it more suitable for passivation/stabilization of HMs in groundwater/soil. Furthermore, the production cost of nZVI@SS was approximately 50 $/T, below the average market value of comparable adsorption materials. This method made low-grade minerals into environmentally friendly materials with high added value, significantly reduced the environmental risk of HMs in water/soil, and provided a new approach for the development of sustainable environmentally friendly materials using hazardous waste RS as a resource.