Development of a high-efficiency phosphorus recovery method using a fluidized-bed crystallized phosphorus removal...

Area of Science:

• Environmental Engineering
• Chemical Engineering
• Materials Science

Background:

• Conventional single-tank fluidized-bed systems for Magnesium Ammonium Phosphate (MAP) recovery face challenges with excessive crystal growth.
• Overgrown MAP crystals reduce effective surface area and degrade fluidization, leading to decreased phosphorus recovery efficiency.
• This limitation hinders stable and efficient phosphorus removal from wastewater.

Purpose of the Study:

• To develop and evaluate an improved fluidized-bed crystallized phosphorus removal system for enhanced MAP recovery.
• To address the limitations of single-tank reactors by implementing a two-tank system.
• To achieve stable and high phosphorus recovery ratios through controlled MAP particle size.

Main Methods:

• Development of a novel two-tank fluidized-bed reactor system, comprising a main and a sub-reaction tank.
• Utilizing seed crystals for MAP crystallization on their surfaces within the fluidized bed.
• Conducting a pilot experimental system demonstration test to validate the two-tank reactor's performance.

Main Results:

• The two-tank system successfully maintained a constant mean MAP particle size in the main reaction tank.
• Treated water phosphorus concentrations ranged from 14.0 to 79.5 mg/L, with phosphorus recovery ratios between 84% and 92%.
• The system consistently achieved phosphorus recovery ratios above 80%, demonstrating stable and effective treatment.

Conclusions:

• The two-tank fluidized-bed system offers a significant advancement in MAP recovery technology.
• Maintaining constant MAP particle size is crucial for stable and high-efficiency phosphorus removal.
• This innovative approach provides a reliable solution for wastewater phosphorus management and resource recovery.