Inertization of hazardous dredging spoils

• Published in: Waste management (Elmsford) 2002-01, Vol.22 (8), p.865-869
• Main Authors: Giulio Bernstein, Alberto, Bonsembiante, Enrico, Brusatin, Giovanna, Calzolari, Giacomo, Colombo, Paolo, Dall'Igna, Roberto, Hreglich, Sandro, Scarinci, Giovanni
• Format: Article
• Language: English
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramics; Chemical industry and chemicals; Conservation of Natural Resources; Construction Materials; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Geologic Sediments - chemistry; Glass-ceramics; Glasses; Hazardous Substances; Hot Temperature; Metals, Heavy - chemistry; Metals, Heavy - isolation & purification; Other wastes and particular components of wastes; Pollution; Pollution, environment geology; Wastes
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/S0956-053X(02)00076-4

Vitrification and production of ceramics materials starting from sediment excavated from Venice lagoon is described. This sediment is classified as toxic waste because contains several heavy metal ions and organic pollutants and was successfully vitrified at 1200–1350 °C. Twenty weight percentage of glass cullet, coming from a community glass recycling program, was added to the raw materials, previously calcined at 900 °C, as a way of adjusting the variations of composition of the individual sediment batches. Chemical durability (leaching) tests showed that the optimized glass compositions are inert, and thus not only volume reduction but also inertization of the waste was obtained by this process. Moreover, the economics of the entire process was analysed. The valorization of the waste was accomplished by the subsequent processing of the glass derived from the inertization. Glass ceramic materials were produced by viscous phase sintering of pressed glass powders which crystallized during the densification process. Sintered glass ceramic products had good mechanical characteristics (HV=7.5 GPa, bending strength 150±8 MPa), making them suitable for applications in the building industry.