Phosphorus recovery from aqueous solutions via phase separation using bioinspired coacervates
Xiaocui Fan1, Bin Liu2, Jie Xu3
1College of Engineering, Shandong Xiehe University, Jinan 250109, China; College of Resources and Environment, Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, Southwest University, Chongqing 400716, China.
Journal of Environmental Sciences (China)
|July 2, 2025
Summary
Recovering phosphorus (P) from wastewater is vital for sustainability. Bioinspired poly(ethylenimine)-poly(acrylamide-co-acrylic acid) (PEI-PAMcoAA) coacervates efficiently remove P, with potential for fertilizer reuse.
Area of Science:
- Environmental Chemistry
- Materials Science
- Sustainable Engineering
Background:
- Phosphorus (P) is essential for agriculture but a water contaminant causing eutrophication.
- Sustainable P management requires efficient wastewater recovery methods.
- Bioinspired coacervates offer a novel approach for phosphorus removal.
Purpose of the Study:
- To investigate phosphorus (P) removal from aqueous solutions using poly(ethylenimine)-poly(acrylamide-co-acrylic acid) (PEI-PAMcoAA) coacervates.
- To optimize P removal efficiency by examining key parameters like coacervate composition, pH, initial P concentration, and calcium addition.
- To assess the potential for reusing recovered P as a fertilizer.
Main Methods:
- Synthesized bioinspired PEI-PAMcoAA coacervates for P adsorption.
- Systematically varied PEI:PAMcoAA ratios, solution pH, initial P concentrations, and calcium concentrations.
- Quantified P removal efficiency using adsorption studies and analyzed P speciation within coacervates.
Main Results:
- Optimized PEI:PAMcoAA ratio significantly enhanced P removal from 47.21% to 95.44%.
- PEI-PAMcoAA coacervates achieved 77.96% P removal efficiency at neutral pH without calcium via electrostatic adsorption.
- Calcium addition under alkaline conditions improved P removal to 82.42% by facilitating precipitation and providing binding sites.
Conclusions:
- PEI-PAMcoAA coacervates, especially with calcium, demonstrate high efficiency for P removal from wastewater, particularly at low concentrations.
- The recovered P can be potentially reused as a non-toxic fertilizer, contributing to a circular economy.
- This bioinspired coacervate approach offers a simple, effective, and environmentally friendly solution for sustainable P management.
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