查找使用阿拉丁产品的科研文献

Effect of Co-Existing Cations and Anions on the Adsorption of Antibiotics on Iron-Containing Minerals

Xiaoyu Guan,Juntao Guo,Hui Zhang,Shiyong Tao,Gilles Mailhot,Feng Wu,Jing Xu

The adsorption of antibiotics on minerals is an important process in their environment behavior. The adsorption behavior of antibiotics on iron-containing minerals and the effect of co-existing cations and anions were studied in this work. Magnetite, hematite, goethite and kaolin were selected as the representative minerals and characterized by SEM, XRD and BET. A total of eight antibiotics, including three quinolones, three sulfonamides and two mycins were chosen as the research targets. Results showed a higher adsorption amount of quinolones than that of sulfonamides and mycins on the surface of iron-containing minerals in most mineral systems. The adsorption isotherms of quinolones can be well fitted using the Freundlich models. The effects of five cations and five anions on the adsorption of quinolones were investigated, among which Mg2+, Ca2+, HCO3−and H2PO4−mainly showed significant inhibition on the adsorption, while the effects of K+, Na+, NH4+, Cl−, NO3−and SO42−showed less. Natural surface water samples were also collected and used as media to investigate the adsorption behavior of quinolones on iron-containing minerals. The buffering capacity of the natural water kept the reaction solution at circumneutral conditions, and the adsorption amount was mostly promoted in the goethite system (from 0.56~0.78 μmol/g to 0.52~1.43 μmol/g), but was inhibited in the other systems (magnetite: from 1.13~1.33 μmol/g to 0.45~0.76 μmol/g; hematite: from 0.52~0.65 μmol/g to 0.02~0.18 μmol/g; kaolin: from 1.98~1.99 μmol/g to 0.90~1.40 μmol/g). The results in this work help to further understand the transportation and fate of antibiotics in an aqueous environment.Keywords:antibiotics;iron-containing minerals;adsorption;co-existing ions;natural surface water

FeOCl-confined activated carbon for improving intraparticle Fenton-like oxidation regeneration

Qianxin Zhang,Menghan Zhang,Tong Li,Roujia Du,Gang Yu,Shubo Deng

Highly efficient oxidation , as non-thermal regeneration technology , is a promising method to solve the regeneration problem of spent activated carbon (AC) in wastewater treatment . In this study, FeOCl was confined into activated carbon (FeOCl/AC) for catalytic oxidation of contaminants on AC during the regeneration process. The characterization results of FeOCl/AC showed that amorphous FeOCl was distributed in micropores, mesopores and macropores of AC. The methylene blue (MB)-adsorbed FeOCl/AC had a regeneration efficiency of 93.7 % at neutral pH in the presence of H 2 O 2 , much higher than 46.9 % by Fenton oxidation and 33.7 % by H 2 O 2 oxidation. Meanwhile, the spent FeOCl/AC after the adsorption of atrazine, 2,4-dichlorophenol, and ofloxacin had the regeneration efficiencies of 71.5 %, 86.4 %, and 100 %, respectively. Moreover, the regeneration efficiency still reached 87 % in the fifth adsorption-regeneration cycle, and was linearly decreased with the increase of adsorbed amounts of MB. During 6 h regeneration of spent FeOCl/AC, 97 % of adsorbed MB was degraded. Electron paramagnetic resonance and radical trapping experiments indicated that both superoxide and hydroxyl radicals were involved in MB oxidation during the regeneration process.

Ratiometric fluorescent immunochromatography for simultaneously detection of two nitrofuran metabolites in seafoods

Yuanyuan Cheng,Xiuying Liu,Min Yang,Fei Xia,Ling Fan,Xue Gao,Xiaofei Sun,Lijie Zhu

Competitive immunochromatographic assay (ICA) has been widely used in food safety on-site monitoring. However, traditional competitive ICA relies on the change of single-signal intensity to discriminate the results, leading to limited sensitivity and accuracy of naked-eye visual inspection. In this study, we developed a sensitive ratiometric fluorescent immunochromatographic assay (RFICA) judging results based on the color changes of fluorescence. Two different color quantum dot nanobeads (QBs) were introduced as signal labels for rapid and accurate detection of 3-amino-2-oxazolidinone (AOZ) and semicarbazide (SEM) in seafoods. Under the optimal conditions, the visual detection limit for 2-NPAOZ and 2-NPSEM reached up to 1 and 0.5 ng/mL, which were 5- and 14-fold lower than that of traditional single-signal response fluorescent ICA strips. In addition, the RFICA strips were applied to real samples with acceptable recoveries of 81.33 ∼ 99.23 %. These results demonstrate that the developed RFICA platform possesses considerable potential in the on-site detection.

Preparation of ZnFe2O4@TiO2 Novel Core-Shell Photocatalyst by Ultrasonic Method and Its Photocatalytic Degradation Activity

Renhua Chen,Suying Ding,Bo Wang,Xuechang Ren

ZnFe2O4microspheres were prepared by solvothermal method, and a novel ZnFe2O4@TiO2core-shell composite photocatalyst was prepared by ultrasonic (denoted as ZT-x) and mechanical stirring (denoted as ZTM-1.2). The morphology, structure, magnetic, and optoelectronic properties of the catalyst were investigated comprehensively, and the degradation performance of the catalyst was explored through the photocatalytic degradation of Rhodamine B (RhB) under UV light. The concentration of RhB was 10 mg/L, and the catalyst concentration was 0.3 g/L. ZT-1.2 showed the best photocatalytic degradation activity, and the degradation rate of RhB reached 97.3% within 60 min. The degradation ability of the catalyst was further evaluated by Methylene blue (MB), Methyl orange (MO), Phenol, and Ofloxacin (OFX). ZT-1.2 also exhibited excellent stability. The improved catalyst degradation performance was attributed to constructing a Z-type heterojunction. Moreover, the low-efficiency degradation of ZTM-1.2 was caused by catalyst agglomeration and low TiO2loading, confirming the superiority of the ultrasonic method and providing a new method for the preparation of magnetically recoverable TiO2-based core-shell photocatalyst.Keywords:ZnFe2O4@TiO2;ultrasonic;nanocomposites;photocatalysis

Enhanced adsorption properties of polyoxometalates/coal gangue composite:The key role of kaolinite-rich coal gangue

Hao Zhang,Rongbo Zhao,Zhiliang Liu,Xiangchao Zhang,Chunfang Du

As a kind of solid waste, kaolinite-rich coal gangue (CG) occupies many lands and brings great pollution to the environment. Ciprofloxacin (CIP), as a widely used antibiotic, can not only easily lead to bacterial resistance, but also cause serious impacts on the environment and thus threaten human health. Therefore, the comprehensive utilization of kaolinite-rich CG and removal of CIP are definitely imminent. In this study, a series of adsorbents ammonium phosphotungstate/CG (NH 4 -PW/CG) were synthesized through a simple precipitation method using kaolinite-rich CG as a support for the removal of CIP. The obtained NH 4 -PW/CG displayed the excellent adsorption efficiency (82%) toward CIP within 10 min, which was much higher than NH 4 -PW (25%) and CG (10%), respectively. The presence of kaolinite-rich CG made the surface charges of composite NH 4 -PW/CG more negative and the particle size of NH 4 -PW smaller, both of which contributed to the enhanced adsorption efficiency of NH 4 -PW/CG. This work offers a new strategy for the comprehensive utilization of kaolinite-rich CG and provides an efficient adsorbent for the removal of positively charged pollutants.

An AuNPs-Based Fluorescent Sensor with Truncated Aptamer for Detection of Sulfaquinoxaline in Water

Xingyue Chen,Lulan Yang,Jiaming Tang,Xu Wen,Xiaoling Zheng,Lingling Chen,Jiaqi Li,Yong Xie,Tao Le

Herein, we developed a novel truncation technique for aptamer sequences to fabricate highly sensitive aptasensors based on molecular docking and molecular dynamics simulations. The binding mechanism and energy composition of the aptamer/sulfaquinoxaline (SQX) complexes were investigated. We successfully obtained a new SQX-specific aptamer (SBA28-1: CCCTAGGGG) with high affinity (Kd= 27.36 nM) and high specificity determined using graphene oxide. This aptamer has a unique stem-loop structure that can bind to SQX. Then, we fabricated a fluorescence aptasensor based on SBA28-1, gold nanoparticles (AuNPs), and rhodamine B (RhoB) that presented a good linear range of 1.25–160 ng/mL and a limit of detection of 1.04 ng/mL. When used to analyze water samples, the aptasensor presented acceptable recovery rates of 93.1–100.1% and coefficients of variation (CVs) of 2.2–10.2%. In conclusion, the fluorescence aptasensor can accurately and sensitively detect SQX in water samples and has good application prospects.Keywords:molecular docking;molecular dynamics simulations;aptamer truncation;fluorescence aptasensor;gold nanoparticles

Quantum dot nanobead immunochromatographic assay based on bispecific monoclonal antibody for the simultaneous detection of aflatoxin B1 and amantadine

Kezhuo Zhang,Huadong Cai,Min Lu,Daixian Wei,Jiaqi Yin,Nengshui Ding,Weihua Lai,Juan Peng

Durable and eco-friendly peroxymonosulfate activation over cobalt/tin oxides-based heterostructures for antibiotics removal: Insight to mechanism, degradation pathway

Weihong Wang,Fanyue Song,Chunfang Du,Yiguo Su

Potential leaching of Co ions could decrease the catalytic activity and cause secondary pollution of water, thereby threatening ecological safety and human health. In response, the in-situ generation of well-dispersed Co 2 SnO 4 and SnO 2 with fine interfacial feature was constructed for PMS activation toward efficient tetracycline degradation and lower cobalt ion leaching feature. The synergistic effect of Co 2 SnO 4 and SnO 2 endowed Co 2 SnO 4 -SnO 2 an outstanding catalytic performance for tetracycline degradation in alkaline condition. Meanwhile, the catalysts can effectively degrade the quinolones, dyes and mixture pollutant solution. The excellent performance can attributed to the in-situ introduction of SnO 2 , which stabilizes the microstructure and provides an effective electronic pathway to enhance the activity of Co 2 SnO 4 in the Co 2 SnO 4 -SnO 2 . In optimized condition, the tetracycline degradation efficiency was enhanced to 94.9% within 20 min and maintained the stability at least four cycles. The degradation rate constant of Co 2 SnO 4 -SnO 2 was 0.149 min −1 , which was about 1.93, 2.98, 11.5 times higher than of Co 2 SnO 4 , Co 3 O 4 and SnO 2 , respectively. Notably, the leaching performance of Co 2 SnO 4 -SnO 2 was greatly suppressed to be 7.45 ug/L, which was lower than that of Co 2 SnO 4 (6.41 mg/L) and Co 3 O 4 (1.12 mg/L). Radical quenching and EPR experiments showed that singlet oxygen ( 1 O 2 ), rather than hydroxyl active species and sulfate radicals, played a predominating role for PMS activation in the Co 2 SnO 4 -SnO 2 /PMS system. The intermediates and degradation routes for tetracycline degradation were characterized by liquid chromatograph-tandem mass spectrometry. This study expected to provide a novel strategy to construct heterostructural catalysts with lower cobalt ion leaching for the activation of PMS.

Versatile pathways for oxidating organics via peroxymonosulfate activation by different single atom catalysts confining with Fe–N4 or Cu–N4 sites

Mengxue Yang,Ruixian Wu,Shengshuai Cao,Yanwei Li,Sisi Huo,Wei Wang,Zhen Hu,Xing Xu

Herein, we prepared two kinds of single-atom catalysts (SACs) with uniformed coordination structures (M−N 4 , M = Fe, and Cu) for evaluating the versatile pathways of peroxymonosulfate (PMS) activation by different metal sites. Fe-SAC exhibited a higher catalytic performance than that of Cu-SAC for chloroquine phosphate (CQP) oxidation. Results showed that the high-valent iron-oxo species accounted for 74.5 % for CQP oxidation in Fe-SAC/PMS system, while radicals (SO 4 •– and HO • ) dominated the CQP oxidation (58.3 %) in Cu-SAC/PMS system, which was associated to the different spin-state of the metal sites for PMS adsorption and breakage of O O in PMS as well as the intermediates in versatile pathways. The SACs were then fixed onto the catalytic filter for PMS activation , which showed stable and effective catalytic performance for versatile recalcitrant organics. Overall, this work not only provided the atomic-level knowledge on PMS activation, but also gave the potential applications of Fenton-like for water remediation.

A high-performance SERS imprinted membrane based on Ag/CNTs for selective detection of spiramycin

Hongji Li,Junfu Wang,Xiyue Wang,Haochen Yu,Linjing Ji,Tianyu Zhou,Chunbo Liu,Guangbo Che,Dandan Wang

In this test, the eggshell membrane (ESM) is selected as the support membrane for the biocompatibility and anchors CNTs on the surface to increase the mechanical properties. Then Ag NPs are decorated on CNTs-ESM substrate as SERS substrate by twice in-situ reduction. Finally, a layer of imprinted polymers is coated on the surface of the substrate to synthesize the imprinted membrane for selective detection of spiramycin. It is exhibited from the characteristic results that the CNTs significantly increase the mechanical properties and the detection sensitivity, simultaneously. When the concentration of SP changes between 10 -6  ∼ 10 -11 M, there is a linear relationship between SERS intensity and SP concentration. The detection limit is 10 -11 M, and the correlation coefficient R 2 is 0.9864. The SERS imprinted membrane can be applied into the detection of antibiotics in practical sample, which broadens the research field of antibiotics detection.

Towards the rapid detection of multiple antibiotics in eggs by Surface-enhanced Raman spectroscopy coupled with hollow fiber micro-extraction

Mengke Jin,Xue Wang,Mohammad Russel,Jiajia Shan

Surface-enhanced Raman Spectroscopy (SERS) is an alternative tool in the field of food safety detection. Complicated food sample preparations are the key challenges to use SERS analysis for rapid food test. This study proposed a novel, facile and sensitive hollow fiber liquid-phase micro-extraction coupled with SERS (HF-LPME-SERS) technique for rapid detection of multiple antibiotic residues in eggs samples. The parameters affecting the extraction efficiency were optimized, and the optimized HF-LPME method could extract antibiotics from egg samples directly. That is eased up to sample preparation steps and promotes the SERS to rapid food testing. Moreover, here reported a simple preparation and cost-effective laser induced self-assembly SERS substrate; and applied it to SERS spectra measurement of the extract. The minimum detection concentration was 10 ng/g achieved for multiple antibiotics, which demonstrated the superior SERS performance. The proposed HF-LPME-SERS method provides easy sample operation, low reagent cost and high sensitivity, which would be a green and rapid analytical approach to detect the trace amount of hazardous substances in food.

Molecularly imprinted electrochemical sensor based on multi-walled carbon nanotubes for specific recognition and determination of chloramphenicol in milk

Lingjun Geng,Jingcheng Huang,Hongguo Zhai,Zheng Shen,Jie Han,Yanyang Yu,Honggang Fang,Falan Li,Xia Sun,Yemin Guo

A molecularly imprinted electrochemical sensor of chloramphenicol (CAP) with high sensitivity and good selectivity is introduced in this paper. Glassy carbon electrode (GCE) was modified by chitosan-multiwalled carbon nanotubes (CS-MWCNTs), the CS could improve the dispersion of MWCNTS, and the MWCNTS could significantly improve the current response of the sensor, thus improving the sensitivity. CAP was used as a template molecule and o-phenylenediamine (o-PD) was used as a functional monomer, respectively. Molecularly imprinted polymers (MIPs) were prepared on the surface of a GCE modified with CS-MWCNTs by electro-polymerization. The MIPs provided specific recognition sites for the detection of chloramphenicol. The experimental parameters such as polymerization cycle, concentration ratio of template molecule to functional monomer, supporting electrolyte pH and incubation time were optimized. Under optimized experimental conditions, the sensor has a linear range of 0.1–1000 ng/mL and the limit of detection (LOD) of 3.3 × 10 −2 ng/mL (S/N = 3). The sensor had high selectivity, good stability and reproducibility for the detection of CAP, and it has been successfully used for the determination of CAP in real spiked milk samples.