Marble Waste Sludges as Effective Nanomaterials for Cu (II) Adsorption in Aqueous Media
Metadatos
Mostrar el registro completo del ítemAutor
Castillo Ramos, Ventura; Rivera Utrilla, José; Ruiz Sánchez, Antonio; López Ramón, María Victoria; Sánchez Polo, ManuelEditorial
MDPI
Materia
Marble waste sludge Copper Adsorption Water remediation Kinetics Isotherms
Fecha
2021Referencia bibliográfica
Ramos, V.C.; Utrilla, J.R.; Sánchez, A.R.; Ramón, M.V.L.; Polo, M.S. Marble Waste Sludges as Effective Nanomaterials for Cu (II) Adsorption in Aqueous Media. Nanomaterials 2021, 11, 2305. https:// doi.org/10.3390/nano11092305
Patrocinador
Junta de Andalucía and Fondo Europeo de Desarrollo Regional (FEDER) Ref. P18-RT-4193Resumen
This study evaluated the waste generated by a Spanish marble-producing company as
adsorbent for the removal of copper (Cu [II]) from aqueous media. Six marble waste sludge samples
were studied, and the following operational parameters were analyzed in discontinuous regime,
including pollutant concentration, pH, temperature, nature of aqueous medium, and ionic strength.
The applicability of the adsorbent material was assessed with experiments in both continuous and
discontinuous regimes under close-to-real-life conditions. A pseudo-second order model yielded
a better fit to the kinetic data. Application of the intraparticle diffusion model revealed two welldifferentiated adsorption stages, in which the external material transfer is negligible and intraparticle
diffusion is the controlling stage. The equilibrium study was better fitted to a Freundlich-type
isotherm, predicting elevated maximum adsorption values (22.7 mg g−1
) at a relatively low initial
Cu (II) concentration (25 ppm), yielding a highly favorable chemisorption process (n >> 1). Xray fluorescence study identified calcite (CaCO3
) as the main component of marble waste sludges.
According to X-ray diffraction analysis, Cu (II) ion adsorption occurred by intercalation of the
metallic cation between CaCO3
layers and by the formation of surface complexes such as CaCO3
and Cu2
(CO3
)(OH)2
. Cu (II) was more effectively removed at medium pH, lower temperature, and
lower ionic strength of the aqueous medium. The salinity and dissolved organic matter in surface,
ground-, and waste-waters negatively affected the Cu (II) removal process in both continuous and
discontinuous regimes by competing for active adsorption sites. These findings demonstrate the
applicability and effectiveness of marble-derived waste sludges as low-cost and readily available
adsorbents for the treatment of waters polluted by Cu (II) under close-to-real-life conditions.