In this study, removal of Cu(2+), Cd(2+) and Pb(2+) from aqueous solutions by adsorption onto pyrite and synthetic iron sulphide (SIS) was investigated as a function of pH, contact time, adsorbent dosage, initial metal concentration and temperature. It has been determined that the adsorption of metal ions onto both adsorbents is pH dependent and the adsorption capacities increase with the increasing temperature. The mechanisms governing the metal removal processes were determined as chemical precipitation at low pH (<3) due to H(2)S generation and adsorption at high pH (in the range of 3-6). The metal adsorption yields also increased with the increasing adsorbent dosage and contact time and reached to equilibrium for both adsorbents. The Cu(2+), Cd(2+) and Pb(2+) adsorption capacities of both adsorbents decrease in the order of Pb(2+)>Cu(2+)>Cd(2+). Except for cadmium, little fraction of copper and lead in the solid adsorption residues was desorbed in acidic media.
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http://dx.doi.org/10.1016/j.jhazmat.2006.02.051 | DOI Listing |
RSC Adv
January 2025
Gansu Zhongshang Food Quality Test and Detection Co., Ltd Lanzhou 730010 China.
Ferrihydrite (Fh), a widely distributed mineral in the environment, plays a crucial role in the geochemical cycling of elements. This study used experimental and computational approaches to investigate the adsorption behavior of seven heavy metal ions on Fh. The pH edge analysis revealed that the adsorption capacity followed the order: Pb > Cu > Zn > Cd > Ni > Co > Mn, with Pb showed the highest adsorption.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Pharmaceutical Chemistry, College of Pharmacy King Saud University, Riyadh Saudi Arabia.
In this study, an optical sensor, JA/(2,6-di((E)-benzylidene)cyclohexan-1-one), was synthesized and characterized using H NMR and FT-IR spectroscopy. The sensor exhibited high efficiency and selectivity in detecting Pb ions, even in the presence of potential interfering ions such as Mn, Cu, Co, Cr, Ni, Ce, Hg, and Cd in aqueous solutions. The interaction of JA with Pb resulted in a significant enhancement of fluorescence intensity, suggesting the formation of a stable complex.
View Article and Find Full Text PDFSci Rep
January 2025
Geology Department, Faculty of Science, Assiut University, Assiut, Egypt.
Limestone mining waste and its derived CaO were checked as an adsorbents of pb, Cu, and Cd ions from water solution. The characterization of Limestone and calcined limestone was studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), and Surface area measurements (BET). The optimum conditions of sorbent dosage, pH, initial concentration, and contact time factors were investigated for pristine limestone and calcined limestone absorbents.
View Article and Find Full Text PDFMolecules
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.
View Article and Find Full Text PDFNanomaterials (Basel)
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.
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