Assessment of sorption capability of montmorillonite clay for lead removal from water using laser–induced breakdown spectroscopy and atomic absorption spectroscopy

TERÁN, E.J.; MONTES, M.L.; RODRÍGUEZ, C.; MARTINO, L.; QUIROGA, M.; LANDA, R.; TORRES SÁNCHEZ, R.M.; DÍAZ PACE, D.M.

MICROCHEMICAL JOURNAL

ELSEVIER SCIENCE BV

Año: 2019 vol. 144 p. 159 - 165

0026-265X

Laser?induced breakdown spectroscopy (LIBS) and atomic absorption spectroscopy (AAS) techniques were appliedfor quantitative analysis of the remaining Pb content in water samples after treatment with a raw montmorillonite(MMT) and an organic derivative (MMO) clays for heavy metal removal, an issue of crucial importancefor decontamination of water bodies. The Pb sorption capabilities of MMT and MMO clays wereassessed by using solutions with known Pb concentrations, in the range 100?500 ppm. To carry out the LIBSanalysis, the samples were prepared in the form of solid pellets with powdered calcium hydroxide addition. Themeasurement conditions were optimized to achieve reliable analytical results and the plasma parameters, i.e.,temperature and electron density, were obtained. For quantification purpose, a calibration curve was constructedwith the Pb I emission line at 4057.8 Å measured at the time window 30?45 μs by using referencesamples with Pb concentrations in the range 56?715 ppm. The Pb residual content in the liquid samples determinedwith LIBS showed a good agreement with those measured with AAS. The sorption efficiency of Pb fromcontaminated water was calculated through a sorption percentage SPb%. The calculated SPb% was higher forMMT (56%?100%) than for MMO (27%?47%). The results also demonstrated the usefulness of LIBS method forthe determination of Pb concentrations in liquid samples.