Waste Brick Dust as Potential Sorbent of Lead and Cesium from Contaminated Water

• Main Authors: Barbora Doušová, David Koloušek, Miloslav Lhotka, Martin Keppert, Martina Urbanová, Libor Kobera, Jiří Brus
• Format: Article
• Language: English
• Published: MDPI AG 2019-05-01
• Series: Materials
• Subjects: waste brick dust; adsorption; lead; cesium; surface complexation; precipitation; solid-state NMR spectroscopy
• Online Access: https://www.mdpi.com/1996-1944/12/10/1647
• ISSN: 1996-1944

Adsorption properties of waste brick dust (WBD) were studied by the removing of Pb^II and Cs^I from an aqueous system. For adsorption experiments, 0.1 M and 0.5 M aqueous solutions of Cs⁺ and Pb²⁺ and two WBD (Libochovice—LB, and Tyn nad Vltavou—TN) in the fraction below 125 µm were used. The structural and surface properties of WBD were characterized by X-ray diffraction (XRD) in combination with solid-state nuclear magnetic resonance (NMR), supplemented by scanning electron microscopy (SEM), specific surface area (S_BET), total pore volume and zero point of charge (pH_ZPC). LB was a more amorphous material showing a better adsorption condition than that of TN. The adsorption process indicated better results for Pb²⁺, due to the inner-sphere surface complexation in all Pb²⁺ systems, supported by the formation of insoluble Pb(OH)₂ precipitation on the sorbent surface. A weak adsorption of Cs⁺ on WBD corresponded to the non-Langmuir adsorption run followed by the outer-sphere surface complexation. The leachability of Pb²⁺ from saturated WBDs varied from 0.001% to 0.3%, while in the case of Cs⁺, 4% to 12% of the initial amount was leached. Both LB and TN met the standards for Pb^II adsorption, yet completely failed for any Cs^I removal from water systems.