Recycled porous glass from municipal/industrial solid wastes sorting operations as a lead ion sorbent from wastewaters

Recycled waste porous glass (RWPG), from municipal solid wastes (MSW) sorting operations, may be used as a sorbent for lead ion removal from industrial wastewaters. To the purpose, dynamic (laboratory columns) operations were carried-out by the use of differently sized glass beads in the range 0.35-1.25 mm which were eluted with lead ion containing synthetic solutions (2-9.5 mg/L). Temperature was kept constant (298 K), whereas column flow-rates varied in the range 0.20-0.75 L/h. Lead ion retention mechanism was associated to the adsorption/ion exchange phenomena. Best column performance was obtained at 0.5-1 mm bead size range, influent concentration 2 mgPb2+/L and column flow-rate 0.20 L/h. In the reference conditions lead ion retention capacity exceeded 1.10 mg/g. Kinetic analysis of the experimental data was also carried-out and film interdiffusion of the involved ions in the Nernst stationary liquid around the particle was identified as the rate controlling step.