[Efficiency of Magnesium Hydroxide Capping and Amendment to Control Phosphorus Release from Sediments]
Chun-Yi Yang1, Yan-Hui Zhan1, Jian-Wei Lin1
1College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
Huan Jing Ke Xue= Huanjing Kexue
|July 2, 2020
Summary
Magnesium hydroxide effectively reduces phosphorus release from freshwater sediments. This study shows magnesium hydroxide capping and amendment control internal phosphorus pollution, crucial for eutrophication management.
Area of Science:
- Environmental Chemistry
- Water Quality Management
Context:
- Eutrophication is a global issue driven by phosphorus (P).
- Internal P release from sediments exacerbates eutrophication.
- Controlling sedimentary P release is vital for freshwater body restoration.
Purpose:
- To investigate magnesium hydroxide [Mg(OH)2] as a capping and amendment material for controlling sedimentary P release.
- To evaluate the adsorption performance of Mg(OH)2 for phosphate.
- To assess the impact of Mg(OH)2 on P mobilization in sediments.
Summary:
- Mg(OH)2 demonstrated effective phosphate adsorption, with efficiency increasing with dosage.
- Adsorption data best fit Freundlich and Dubinin-Radushkevich models.
- Both Mg(OH)2 capping and amendment significantly reduced reactive soluble P (SRP) in overlying and pore waters, particularly in the top sediment layer.
- As-prepared Mg(OH)2 showed superior performance compared to commercial grades.
Impact:
- Mg(OH)2 is a promising material for mitigating internal P release in freshwater ecosystems.
- This approach offers a viable strategy for managing eutrophication.
- Reduces P loading, improving overall water quality.
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