Morphologically controlled synthesis of MgFe-LDH using MgO and succinic acid for enhanced arsenic adsorption: Kinetics, equilibrium, and mechanism studies.
J Environ Sci (China)
; 148: 637-649, 2025 Feb.
Article
en En
| MEDLINE
| ID: mdl-39095196
ABSTRACT
In this study, we investigated improving the performance of a layered double hydroxide (LDH) for the adsorption of As(III) and As(V) by controlling the morphology of LDH crystals. The LDH was synthesized via a simple coprecipitation method using barely soluble MgO as a precursor and succinic acid (SA) as a morphological control agent. Doping the LDH crystals with carboxylate ions (RCOO-) derived from SA caused the crystals to develop in a radial direction. This changed the pore characteristics and increased the density of active surface sites. Subsequently, SA/MgFe-LDH showed excellent affinity for As(III) and As(V) with maximum sorption densities of 2.42 and 1.60 mmol/g, respectively. By comparison, the pristine MgFe-LDH had sorption capacities of 1.56 and 1.31 mmol/g for As(III) and As(V), respectively. The LDH was effective over a wide pH range for As(III) adsorption (pH 3-8.5) and As(V) adsorption (pH 3-6.5). Using a combination of spectroscopy and sorption modeling calculations, the main sorption mechanism of As(III) and As(V) on SA/MgFe-LDH was identified as inner-sphere complexation via ligand exchange with hydroxyl group (-OH) and RCOO-. Specifically, bidentate As-Fe complexes were proposed for both As(III) and As(V) uptake, with the magnitude of formation varying with the initial As concentration. Importantly, the As-laden adsorbent had satisfactory stability in simulated real landfill leachate. These findings demonstrate that SA/MgFe-LDH exhibits considerable potential for remediation of As-contaminated water.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Arsénico
/
Contaminantes Químicos del Agua
/
Ácido Succínico
/
Hidróxidos
/
Óxido de Magnesio
Idioma:
En
Revista:
J Environ Sci (China)
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2025
Tipo del documento:
Article
País de afiliación:
Japón