Natural sediment at a dam and its inorganic materials as adsorbents of praseodymium(Pr(Ⅲ))

• Published in: 国际泥沙研究（英文版） Vol. 48; no. 4; pp. 566 - 575
• Main Authors: Melania Jiménez-Reyes, Jaime Jiménez-Becerril, Marcos Solache-Ríos, Perla Tatiana Almazán-Sánchez
• Format: Journal Article
• Language: English
• Published: Departamento de Química,Instituto Nacional de Investigaciones Nucleares,Carretera México-Toluca S/N,La Marquesa,Ocoyoacac,Estado de México C.P.52750,Mexico%CONACyT-Instituto Nacional de Investigaciones Nucleares,La Marquesa,Ocoyoacac,Estado de México,Mexico 2023
• Subjects: Adsorption process parameters; Sediment; Desorption; Praseodymium
• ISSN: 1001-6279

The sediment deposited behind a dam(DS)and its inorganic materials(IM-DS)were characterized and used for the removal of praseodymium(Pr)from aqueous solutions.Quartz,albite,and kaolinite were found in the sediment by X-ray diffraction.Kinetic data fit well to a pseudo second-order model,the equilibrium time for DS and IM-DS was 2 h and 3 min,respectively,and the adsorption capacity was higher for Pr/DS(qe=4.91 mg/g)than for Pr/IM-DS(qe=3.01 mg/g)in these conditions.Pr/DS and Pr/IM-DS data isotherms were in agreement with the Langmuir-Freundlich model and the maximum adsorption capacities were 4.95 and 4.01 mg/g,respectively.Both processes are exothermic(enthalpy change,ΔH0=-22.8 and-21.8 kJ/mol for DS and IM-DS,respectively),the increase of the randomness is small,and the feasibility and spontaneity are low.Praseodymium was desorbed by ethyl-enediaminetetraacetic acid disodium(EDTA-Na2),sodium chloride,nitric,citric,and humic acids solu-tions,and one hundred percent of praseodymium was desorbed by the EDTA-Na2 solution.The Pr2(EDTA)3(praseodymium ethylenediaminetetraacetate)complex was completely desorbed from both materials(DS and IM-DS).Distribution coefficients(KD)depend upon praseodymium concentration,temperature,pH,and the kind of adsorbent.Chemical reactions of praseodymium with kaolinite and iron minerals could explain the adsorption.