Anoxia remediation and internal loading modulation in eutrophic lakes using geoengineering method based on oxygen...

Area of Science:

• Environmental Science
• Water Chemistry
• Geoengineering

Background:

• Eutrophic lakes suffer from benthic anoxia and internal phosphorus (P) release, degrading aquatic ecosystems.
• Sediment anoxia and P release are exacerbated by algal blooms and decomposition of organic matter.

Purpose of the Study:

• To experimentally evaluate a novel
• flock-lock
• geoengineering method using oxygen nanobubble technology.
• To assess the method's efficacy in remediating sediment anoxia and reducing internal P release in various aquatic conditions.

Main Methods:

• Development of oxygen-carrying materials (OCM) from natural zeolites as capping agents.
• Application of OCM to form an oxygen-locking layer between anoxic sediment and overlying water.
• Experimental evaluation in systems with and without algal blooms, measuring dissolved oxygen (DO) and labile P.

Main Results:

• OCM capping instantly increased overlying DO from ~1.5 mg/L to 3.5-4 mg/L (with blooms) and 5-6 mg/L (without blooms).
• Oxygen penetration depth in sediment increased from 0 cm to 3 cm, forming an oxygen-locking layer.
• Labile P and Fe release was significantly reduced, and oxygen depletion at the sediment-water interface was eliminated.

Conclusions:

• The
• flock-lock
• geoengineering method effectively mitigates sediment anoxia and internal P loading in eutrophic waters.
• This technology offers a sustainable solution for improving water quality and restoring aquatic ecosystem health.
• OCM application demonstrates significant potential for managing phosphorus cycling in lake ecosystems.