In this study, a high-efficiency strontium-doped hydroxyapatite (Sr-HAP) adsorbent was synthesized by a sol-gel method for removing cobaltous ions (Co(II)) from water. The effects of adsorbent dose, initial solution pH, initial Co(II) concentration and temperature on the removal performance of Co(II) were investigated. Experimental results indicated that the optimum Sr-HAP dose was 0.30 g/50 mL solution, the Sr-HAP adsorbent could effectively remove Co(II) in a wide pH range of 3-8. Increasing temperature was conducive to the adsorption, and the maximum Co(II) adsorption capacity by Sr-HAP reached 48.467 mg/g at 45 °C. The adsorption of Co(II) followed the pseudo-second-order kinetic model, indicating that the Co(II) adsorption by Sr-HAP was attributed mainly to chemisorption. The isothermal adsorption results showed that at lower Co(II) equilibrium concentration, the Langmuir model fitted the data better than the Freundlich model but opposite at higher Co(II) equilibrium concentration. Therefore, the adsorption of Co(II) was a process from monolayer adsorption to multilayer adsorption with the increase of the Co(II) equilibrium concentration. The diffusion analysis of Co(II) to Sr-HAP indicated that the internal diffusion and surface adsorption were the rate-controlled steps of Co(II) adsorption. Thermodynamic study demonstrated that the Co(II) adsorption process was spontaneous and endothermic. The mechanism study revealed that in addition to chemisorption, Sr-HAP also removed Co(II) ions from water via ion exchange and surface complexation.
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http://dx.doi.org/10.1007/s11356-024-33239-4 | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Department of Chemical Engineering, Zakir Hussain College of Engineering and Technology, Aligarh Muslim University, Aligarh, 202002, Uttar Pradesh, India.
Water pollution because of the presence of heavy metals remains a serious worry. The present work demonstrates the exclusion of cobalt ion (or Co(II)) from water using novel and cost-effective biosorbents. Initially, the biosorbent was chemically modified using orthophosphoric acid and then subjected to calcination to result acid modified date seed biochar (AMDB).
View Article and Find Full Text PDFEnviron Geochem Health
January 2025
Soil and Water Research Department, Nuclear Research Center, Egyptian Atomic Energy Authority, Cairo, 13759, Egypt.
Fusarium solani biomass plays a significant role in water pollution remediation due to its ability to sequester heavy metals, particularly cobalt (Co(II)) and cadmium (Cd(II)), which pose severe environmental and health risks. This study aimed to identify fungi from sewage-contaminated sites and evaluate their efficiency in absorbing and reducing Co(II) and Cd(II) ions. The biosorption potential of irradiated Fusarium solani biomass for removing Co(II) and Cd(II) ions from aqueous solutions was investigated.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Centre de Recherche Scientifique Et Technique en Analyses Physico-Chimiques, CP 42004, Bou-Ismail, Tipaza, Algeria.
Int J Biol Macromol
December 2024
Department of Chemistry, Imam Khomeini International University, P.O. Box 288, Qazvin, Iran.
A novel nanocomposite magnetic hydrogel was synthesized based on κ-carrageenan, acrylic acid, and activated carbon as an absorbent for removing heavy metal ions from aqueous solution. FT-IR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibration sample magnetometer (VSM) were employed to confirm the structure of the nanocomposite hydrogels. The effects of contact time, pH, particle size, temperature, and metal ion concentration on the metal ion adsorption were investigated.
View Article and Find Full Text PDFEnviron Res
December 2024
Yanshan Earth Critical Zone and Surface Fluxes Research Station, College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address:
N-termini Cyano group (CN) in metal hexacyanoferrates (MHCF) have been identified as specific-affinity sites for palladium (Pd), but C-termini CN do not effectively serve as Pd adsorption sites due to their stronger bonds with the metal ligands (M), which reduces the activity and density of CN. Herein, the optimization of directional coordination of cyano group C/N-termini by modulating the electronic structure of the M (Fe, Co, and Ni) in MHCF was investigated to reinforce the Pd recovery. Spectroscopic analyses and DFT calculations revealed that NiHCF exhibited N-site mono-coordination, whereas CoHCF displayed C-site mono-coordination due to spin-exchange interactions, leading to the strengthened N-Co bonds and weakened Fe-C bonds.
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