Three types of extracellular polymeric substances (EPS), EPS1, EPS2 and EP3, with protein/sugar content ratio of 2.5 : 1, 7 : 1 and 9 : 1, respectively, were investigated as sorbent for adsorbing Cd2+ and Zn2+ from wastewater. The experimental results showed that the adsorption efficiency of EPS toward Cd2+ and Zn2+ were dependent on the composition of EPS. The adsorptive capacities of EPS1, EPS2, EPS3 to Cd2+ were 19.5 mg/g, 27 mg/g, 17 mg/g and to Zn2+ 40.5 mg/g, 47.5 mg/g, 37 mg/g, respectively. Kinetic study showed that EPS1 has the highest reaction rate, while EPS2 has the highest adsorption capacity. All of the adsorption processes reached equlibrium within 1 h following both the Freundlich and Langmuir isotherms. The fitted parameters indicated that varied reactions may occur in EPS-metal adsorption process and EPS as adsorbent has much higher adsorption stabilization, adsorption ability and appetency to Zn2+ than to Cd2+. The adsorption capacity of EPS toward Cd2+ and Zn2+ increased with the sugar content, which suggests sugar is of great importance in the adsorption.
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Sensors (Basel)
December 2024
Technical Faculty in Bor, University of Belgrade, Vojske Jugoslavije 12, P.O. Box 50, 19210 Bor, Serbia.
Cadmium is one of the most dangerous pollutants found in the environment, where it exists mainly due to human activities. High cadmium concentrations can cause serious problems, which is why the detection and determination of Cd is one of the most important tasks. Electroanalytical methods provide rapid and accurate results in the detection of cadmium in various solutions.
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December 2024
Centre for Research University Services (CeSAR), Università degli Studi di Cagliari, S.S. 554 Bivio per Sestu, 09042 Monserrato, Italy.
2,8-Dithia-5-aza-2,6-pyridinophane () has been used as a receptor unit in the construction of the conjugated redox chemosensor 5-ferrocenylmethyl-2,8-dithia-5-aza-2,6-pyridinophane (). In order to further explore the coordination chemistry of , and comparatively, that of its structural analogue 2,11-dithia-5,8-diaza-2,6-pyridinophane (), featuring two secondary nitrogen atoms in the macrocyclic unit, the crystal structures of the new synthesised complexes [Pb()(ClO)]·½CHCN, [Cu()](ClO)·CHCN and [Cd()(NO)]NO were determined by X-ray diffraction analysis. The electrochemical response of towards the metal ions Cu, Zn, Cd, Hg, and Pb was investigated by cyclic voltammetry (CV) in CHCl/CHCN 0.
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January 2025
Department of Chemistry and NIS Centre, University of Torino, Via Giuria 7, 10125 Torino, Italy.
Heavy metals are life-threatening pollutions because of their great toxicity, long-term persistence in nature and their bioaccumulation in living organisms. In this work, we performed multivariate curve resolution-alternating least squares analysis of UV-Vis raw spectra received by a colorimetric sensor constructed on mercaptoundecanoic acid functionalized silver nanoparticles (AgNPs@11MUA) to detect Cd, Cu, Mn, Ni, and Zn in water. This combined approach allowed the rapid identification and quantification of multiple heavy metals and showed adequate sensitivity and selectivity, thus representing a promising analytical and computational method for both laboratory and field applications such as environmental safety and public health monitoring.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Center for Engineering, Modeling, and Applied Sciences (CECS), Federal University of ABC (UFABC), São Paulo 09210-580, Brazil. Electronic address:
The scarcity of water resources and their pollution are vital to modern civilization. Thus, adsorptive membranes are promising candidates to be applied in the filtration systems to improve the water quality. In summary, this study investigated the effect of chitosan (CS) in the morphological, chemical, and physical aspects of PLA-based membranes incorporating chitosan obtained by electrospinning process, their adsorption behavior in multielement aqueous systems containing Cr, Cu, Zn, Mn , Ni, and Cd in pH 4, and the possible removal mechanism on the composite electrospun membrane's surface.
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January 2025
Laboratory for Molecular & Functional Design, Department of Engineering, Nara Women's University, Nara 630-8506, Japan.
Rational molecular design afforded fluorescent Cd sensors based on bisquinoline derivatives. Introduction of three methoxy groups at the 5,6,7-positions of the quinoline rings of BQDMEN (,'-bis(2-quinolylmethyl)-,'-dimethylethylenediamine) resulted in the reversal of metal ion selectivity in fluorescence enhancement from zinc to cadmium. Introduction of bulky alkyl groups and an ,-bis(2-quinolylmethyl)amine structure, as well as replacement of one of the two tertiary amine binding sites with an oxygen atom and the use of a 1,2-phenylene backbone significantly improved the Cd specificity.
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