Pollution Status of River and Lake Sediments and Research Progress in In-situ Remediation Technologies
River and lake sediments, as both sources and sinks of water pollutants, significantly impact overlying water quality and aquatic ecosystems. In pollution treatment and ecological restoration, managing contaminated sediments is critical. Remediation technologies are categorized into ex-situ and in-situ methods; in-situ techniques have gained prominence due to lower costs and minimal environmental disturbance. This review summarizes sediment pollution status, comprehensively examines physical, chemical, biological, and combined in-situ remediation technologies, and discusses their mechanisms, applications, and future research needs. It proposes optimization strategies for emerging technologies, material improvements, and pathways for sustainable development, emphasizing interdisciplinary integration to enhance remediation efficacy. Key pollutants include heavy metals (e.g., Cd, Hg), persistent organic pollutants (POPs), and emerging contaminants like antibiotics and microplastics. In-situ methods such as capping, chemical oxidation, and bioremediation show promise but face challenges in long-term stability and scalability. The paper underscores the need for sustainable, cost-effective solutions and highlights recent advances in combined technologies, offering a reference for future research and engineering applications.