Inertization of hazardous dredging spoils

Area of Science:

• Waste Management
• Materials Science
• Environmental Engineering

Background:

• Venice lagoon sediment is classified as toxic waste due to heavy metals and organic pollutants.
• Effective and sustainable waste management strategies are crucial for environmental protection.

Purpose of the Study:

• To vitrify toxic Venice lagoon sediment into inert glass-ceramic materials.
• To assess the feasibility of using recycled glass cullet to stabilize sediment composition.
• To evaluate the mechanical properties and potential applications of the resulting glass-ceramics.

Main Methods:

• Sediment was calcined at 900°C and mixed with 20 wt% recycled glass cullet.
• Vitrification was performed at temperatures ranging from 1200°C to 1350°C.
• Chemical durability (leaching) tests and mechanical property assessments (Vickers hardness, bending strength) were conducted.

Main Results:

• Vitrification successfully transformed toxic sediment into inert glass.
• Optimized glass compositions demonstrated inertness through leaching tests, confirming waste inertization.
• Glass-ceramic materials exhibited good mechanical characteristics (HV = 7.5 GPa, bending strength 150 ± 8 MPa).

Conclusions:

• Vitrification of Venice lagoon sediment with recycled glass cullet is an effective method for toxic waste management.
• The process achieves both volume reduction and inertization of hazardous waste.
• The produced glass-ceramic materials are suitable for building industry applications, demonstrating successful waste valorization.