Glass from recycling operations as thermal insulating material and sorbent in wastewater treatments

An investigation on potenti al use in the construction industry and in environmental applications (i.e. filtration, heavy metals removal) of porous glass resulting from recyc/ing operations of municipal/industrial solid wastes (Recycled Porous Waste Glass, RPWG) was carried-out. Thanks to the intrinsical/y high porosity of the reference rnaterial, cementitious structures appear particularly Iight and refractory to thermal solicitations. So, the use of this type of glass has been focused on the realization of mortars and lightweight concrete able to improve thermal insulation also combining good mechanical properties. In this context, properties were compared to those of conventional ones, thus showing very interesting results. RPWG may be also used as an alternative material to silica sand filtration media of natura! water, with the additional advantage of selective removal of ionic pollutants such as lead. After comparison of filtration through a glass particle bed with conventional silica sand as control, it was observed that in both cases turbidity abatement exceeded 97% the influent figure. Column headloss of the RPWG was definitely better than the corresponding sandy materia!. As a side benefit, lead ions were a!so uptaken by the glassy material by ion exchange as wel/ as by adsorption. The experiments were carried-out by means of the column method using glass beads which were eluted with synthetic solution. Lead retention capacity exceeded 1.15 mglg at o. 19 L/h flow rate.