Sorption of Pb(II), Cd(II), and Ni(II) From Single- and Multimetal Solutions by Recycled Waste Porous Glass

Abstract

Selective sorption of lead, cadmium, and nickel ions on recycled waste porous glass beads was investigated. Single-metal equilibrations were carried out in demineralized water and ternary metal equilibrations were carried out in demi- and tap water. Freundlich isotherm gave a good correlation of the experimental data. Maximum metal retention (q_max) in single-ion solutions were 18.66 mg/g_RPWG (0.090 mmol/g_RPWG), 4.83 mg/g_RPWG (0.043 mmol/g_RPWG), 4.00 mg/g_RPWG (0.068 mmol/g_RPWG), respectively, for Pb⁺², Cd⁺², and Ni⁺², and lower figures were in the case of ternary systems: 13.50 mg/g_RPWG(0.065 mmol/g_RPWG), 2.23 (0.020 mmol/g_RPWG), 2.05 mg/g_RPWG(0.034 mmol/g_RPWG), respectively, for Pb⁺², Cd⁺², and Ni⁺², with further drastic reduction in tap water. Metal exhausted beads were used as thermal insulators in cement mortars, minimizing their potential impact in the environment.

Keywords:

• Adsorption
• Batch reactors
• Ion exchange
• Polymers
• Porous media
• Wastewater treatment

Acknowledgments

Recycled waste porous glass was kindly supplied by Maltek Industrie S.r.l., Terlizzi, Bari, Italy. Special thanks to Prof. Pietro Stefanizzi and Ubaldo Ayr (Polytechnic University of Bari), for thermal and acoustic measurements.