Porous Waste Glass for Lead Removal in Packed Bed Columns and Reuse in Cement Conglomerates.

Andrea Petrella,Vito Rizzi,Marco Race,Pinalysa Cosma,Stefania Liuzzi,Danilo Spasiano,Nicoletta De Vietro

doi:10.3390/ma12010094

Abstract

A porous waste glass (RWPG = recycled waste porous glass) was used in wastewater treatments for the removal of lead ions from single, binary, and ternary metal solutions (with cadmium and nickel ions). Experiments were performed in columns (30 cm3, 10 g) filled with 0.5–1 mm beads till complete glass exhaustion (breakthrough). In the case of single and binary solutions, the columns were percolated at 0.2 Lh−1 (2 mg Me+2 L−1); in the case of ternary solutions, the columns were percolated at 0.15–0.4 Lh−1 (2 mg Me2+ L−1) and with 2–5 mg Me2+ L−1 influent concentration (0.2 Lh−1). Lead ions were removed mainly by ion exchange and also by adsorption. From a kinetic point of view, the rate controlling step of the process was the interdiffusion of the lead ions in the Nernst stationary liquid film around the sorbent. The uptake of the metals and the glass selectivity were confirmed by Energy Dispersive X-ray spectroscopy (EDX) analysis. After lead retention process, glass beads were reused as lightweight aggregates for thermal insulating and environmental safe mortars.

Highlights

A large number of chemicals are today released in water [1,2,3], land [4,5], or air [6,7], with severe impacts on the environment and on human health
In the case of single and binary solutions, the columns were percolated at 0.2 Lh−1 (2 mg Me+2 L−1 ); in the case of ternary solutions, the columns were percolated at 0.15–0.4 Lh−1 (2 mg Me2+ L−1 ) and with 2–5 mg Me2+ L−1 influent concentration (0.2 Lh−1 )
The approach adopted in this study is in agreement with the principles of the circular economy, since it contributes to the sustainable water treatment and raw material reuse efforts, as reported in many other studies on waste and wastewater treatments [50,51,52,53,54]

Summary

Introduction

A large number of chemicals are today released in water [1,2,3], land [4,5], or air [6,7], with severe impacts on the environment and on human health. In the case of water pollution, the most used approaches to remove heavy metals from wastewaters are adsorption by activated carbon [28,29] and ion exchange by synthetic resins/zeolites [30,31,32,33]. The advantage of the use of this type of cheap sorbent is the re-employment of the metals exhausted glass directly as lightweight aggregate with no problems of hazardous sludge production because the original properties of this secondary raw material (thermal insulation) were preserved. For this reason, RWPG beads were encapsulated in cement conglomerates in order to prevent any release of metals in the environment. The approach adopted in this study is in agreement with the principles of the circular economy, since it contributes to the sustainable water treatment and raw material reuse efforts, as reported in many other studies on waste and wastewater treatments [50,51,52,53,54]

Materials and Methods

Experiments were carried out

Applications of RWPG Beads After Sorption

Results and Discussion

Conclusions