Review of Treatment Techniques for Dredged Sediments in the Context of Valorization as Secondary Raw Materials
Ayodele Afolayan, Robert Černý, Jan Fořt
Abstract
The valorization of dredged sediments (DS) presents a sustainable solution for managing waste while addressing resource scarcity and environmental concerns. This review explores treatment techniques and reuse options for DS, focusing on applications in the construction industry. However, disposal poses challenges due to potential contamination with heavy metals and organic pollutants. The study categorizes treatment approaches into physical, chemical, biological, and thermal processes. Physical methods, such as separation and dewatering, offer volume reduction but have limited capacities against chemically bound contaminants. Chemical treatments, including oxidation and immobilization, target specific pollutants but often entail high costs and environmental risks. Biological approaches, such as bioremediation and phytoremediation, provide sustainable, low-cost alternatives but require longer timescales. Thermal processes like pyrolysis and vitrification efficiently destroy or stabilize contaminants but involve high energy demands. Pyrolysis emerges as a particularly promising technology, combining effective decontamination with energy recovery and biochar production. Despite the advances in the area, the review identifies key barriers to large-scale DS reuse: contamination variability, lack of standardized guidelines, and limited long-term performance data. Future research should focus on integrated treatment strategies, such as combining DS with other industrial by-products, and optimization of processing, aiming to attain cost-effective, sustainable reuse. Overall, the valorization of treated DS supports circular-economy principles and offers significant environmental and economic benefits.