Influence of organic matter on treatment and resource utilization of dredged river sediment.

River sediment dredging is an important way to solve internal pollution in rivers and improve their water environment. How to dispose of and utilize these dredged sediment has become a global environmental issue. Organic matter (OM), as the main component of dredged river sediment, exhibits significant influence on substance migration and transformation, furthering affecting their treatment and resource utilization processes. This review systematically summarizes treatment and resource utilization methods of dredged river sediment, and discusses the influence of OM on these disposal processes. The treatment processes mainly involve in physicochemical and bio-ecological methods. Heterogeneity of OM determines the treatment difficulty of organic-rich sediment. During their treatment processes by advanced oxidation, nanoconfinement-based catalyst design promotes selective non-radical pathways that resist scavenging by humic substances. When reacting with humic substances, the second-order rate constant of 1O2 is 1000 times that of ·OH. Machine learning-assisted optimization enables efficient catalyst screening and precise tuning of reaction parameters. The main resource utilization processes are ecological restoration, construction and building material manufacturing, energy recovery, environmental eco-friendly materials. OM content governs resource utilization strategies of dredged river sediment. The sediment with a low OM content (<5%) is suitably utilized as building materials and ecological substrates, that with medium OM content (5-10%) require pretreatment before utilization. But, when OM content exceeded 10%, the sediment is prioritized for energy recovery, and its calorific value increases by 1.5-2.5 MJ/kg for every 10% increase in OM content. This review systematically elucidates the critical constraints of OM, aiming to provide theoretical basis for selecting cost-effective treatment processes and resource utilization pathways for dredged river sediment with varying OM content, thereby reducing disposal costs and enhancing product quality stability.