Effectiveness of Microbial Composite Strains in Reducing River Sediment

The accumulation of sediment in rivers and lakes can elevate riverbeds, leading to a reduction in river channel flood-carrying capacity, impairment of water conservancy project benefits, and destruction of aquatic ecosystems. Systematic dredging projects are required in the routine maintenance of river channels to ensure flood control safety and ecological health. This study utilized a successfully constructed efficient composite engineering bacterial strain system to conduct field pilot-scale validation in a closed river environment with a water volume of 10,000 cubic meters. Various indicators such as sediment thickness, organic matter, COD (chemical oxygen demand), total nitrogen, and total phosphorus were measured, along with metagenomic analysis, to explore the application effectiveness and feasibility of microbial composite strain technology in river sediment remediation. The results demonstrated that the composite strain technology effectively reduced the thickness and pollutant content of river sediment. The average sediment thickness significantly decreased from 32 cm to 22 cm, with a 10 cm thick mineralized layer forming within two weeks. The reductions in organic matter content, COD content, total nitrogen, and total phosphorus content reached 60.03%, 47.73%, 37.36%, and 29.16%, respectively. Metagenomic analysis revealed that the biodiversity of the treated river channel was higher than that of parallel and control channels at both the phylum and genus levels. The experimental results are useful for optimizing river sediment remediation.