题目 Title

Inhibition of sediment erosion and phosphorus release by remediation strategy of contaminated sediment backfilling.

期刊 Journal

Water Research (IF=12.8)

作者 Author

Li XC; Huang L; Reible D; Zeng X; Liu SW; Fu JH; Wang K; Fang HW

摘要 Abstract

The management of sediment-water interfaces, especially bed stability, is essential for controlling accumulated contaminants in the sediment. In this study, the relationship between sediment erosion and phosphorus (P) release under the remediation strategy of contaminated sediment backfilling (CSBT) was explored through a flume experiment, i.e. the dredged sediment was calcined into ceramsite after dewatering and detoxification and then backfilled to the dredged area for sediment capping, thus avoiding the introduction of foreign materials via in-situ remediation and the large-scale land occupation associated with ex-situ remediation. Acoustic Doppler velocimeter (ADV) and optical backscatter sensor (OBS) were used to measure the vertical distributions of flow velocity and sediment concentration in the overlying water, respectively, and diffusive gradients in thin films (DGT) was used to measure the P distribution in the sediment. The results revealed that improving bed stability from CSBT can considerably improve the robustness of sediment-water interface and reduce sediment erosion by more than 70%. The corresponding P release from the contaminated sediment could be inhibited with an in-hibition efficiency as high as 80%. CSBT is a potent strategy for managing contaminated sediment. This study provides a theoretical reference for controlling sediment pollution, further supporting river and lake ecological management and environmental restoration.

简介 Brief introduction

水-沙交界面处的河床稳定性对于控制底泥污染物的释放至关重要。本研究通过水槽实验，探讨了受污染底泥陶粒化回填技术对底泥上已吸附磷的抑制效果。受污染底泥陶粒化回填技术是先将疏浚底泥脱水干化及无害化处理后，烧结成陶粒并回填至原疏浚区域。采用ADV和浊度仪分别测量水流流速和含沙量，并通过水样测量水体中的磷含量。结果表明，陶粒回填可以增加床面稳定，降低床面侵蚀率（70%以上），同时抑制底泥上已吸附磷的释放（抑制率高达80%）。此外，受污染底泥陶粒化回填技术避免引入外来材料、长期占用土地和二次污染等问题，为控制河流内源污染提供了理论参考，为河湖生态管理和环境恢复提供有力策略。

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