于桥水库生态清淤关键技术研究与工程示范OA

Yuqiao Reservoir serves as a critical regulating storage for the Water Diversion Project from Luanhe River to Tianjin City and is the largest centralized drinking water source for Tianjin Municipality.Due to long-term inputs from upstream inflows and non-point sources within the watershed,internal pollution loads within the reservoir have been continuously accumulating,posing significant constraints on water quality security and aquatic ecological improvement.Ecological dredging,as an effective measure for rapidly removing historically deposited contaminants and interrupting endogenous release,urgently requires the establishment of a whole-process management and control pathway—"precise dredging-pollution prevention and control-beneficial reuse"—that balances engineering efficiency with ecological safety.Drawing upon the 2024 Yuqiao Reservoir dredging pilot project and based on a systematic analysis of the spatial heterogeneity of sediment nutrient distributions and adsorption-desorption characteristics at the sediment-water interface,the dredging area and layered excavation depth were scientifically determined.The construction employed an environmentally friendly cutter-suction dredger for precision operations underwater,minimizing disturbance and pollutant dispersion through cutterhead sealing and automated slurry concentration control.The dredged sediment was treated using a synergistic solidification process that combined phase-change vacuum preloading and mechanical dewatering to achieve rapid volume reduction and stabilization.Tailwater was processed via a"two-stage sedimentation+clarification"system,supplemented by magnetic coagulation precipitation as an emergency safeguard.The solidified sediment was subsequently utilized for ecological restoration within the reservoir area,thereby forming a closed-loop pathway of"pollutant removal-dewatering-water purification-reuse".The pilot project removed a total of 4.99 million cubic meters of contaminated sediment,substantially reducing nitrogen and phosphorus loads,suppressing secondary nutrient release across the sediment-water interface,and disrupting the"pollution-adsorption-release"endogenous cycling,thereby safeguarding the reservoir's water quality.The full-chain technical system developed through this project—"precise dredging-dewatering and volume reduction-tailwater purification-resource reuse"—demonstrates certain technical feasibility and application value for the treatment of internal pollution in large drinking water source areas.