[Adsorption Behavior of Phosphate by CaO₂ Remolded Sediment]

Area of Science:

• Environmental Science
• Geochemistry
• Water Quality Management

Context:

• Sediment contamination with phosphorus is a major issue in aquatic ecosystems, leading to eutrophication.
• Endogenous phosphorus release from sediments exacerbates water quality problems.
• In situ sediment remediation techniques are crucial for restoring degraded water bodies.

Purpose:

• To investigate the effects of calcium peroxide (CaO2) remodeling on sediment properties and phosphorus dynamics.
• To evaluate the efficiency of CaO2 remodeling in reducing endogenous phosphorus release.
• To determine the adsorption behavior and kinetics of phosphate onto CaO2-remodeled sediment.

Summary:

• CaO2 remodeling altered sediment structure, removing organic matter and iron-manganese oxides, increasing porosity, and boosting Ca2+ content.
• Remodeling significantly reduced total phosphorus (TP) by ~20% and active phosphorus by ~30%, stabilizing endogenous phosphorus.
• Phosphate adsorption capacity increased from 1.44 mg·g-1 to 20.91 mg·g-1, with adsorption kinetics best described by a quasi-second-order model.

Impact:

• CaO2 remodeling effectively mitigates endogenous phosphorus release, reducing the risk of eutrophication.
• The enhanced phosphate adsorption capacity of remodeled sediment offers a novel remediation strategy.
• This study provides valuable insights into sediment management and water quality improvement through chemical treatment.