Enhanced phosphate selectivity from wastewater using copper-loaded chelating resin functionalized with...

Area of Science:

• Environmental Science
• Water Chemistry
• Materials Science

Background:

• Phosphate is a critical water contaminant causing harmful algal blooms and eutrophication.
• Stringent regulations necessitate efficient phosphate removal methods for water and wastewater.

Purpose of the Study:

• To evaluate a new commercial chelating resin functionalized with polyethylenimine for enhanced phosphate removal.
• To investigate the selectivity and regeneration capabilities of the modified resin.

Main Methods:

• Batch and column experiments were conducted using a copper-loaded chelating resin (CR20-Cu).
• Phosphate removal efficiency was tested against other anions (sulfate, nitrate, chloride) at varying pH.
• Regeneration capacity was assessed using a 4% NaCl solution.

Main Results:

• CR20-Cu demonstrated high selectivity for phosphate over sulfate and nitrate, with binary separation factors of 7.3 and 4.8, respectively.
• Optimal phosphate removal efficiency was observed at pH 7.
• The resin exhibited a breakthrough sequence of HPO4(2-)>SO4(2-)>NO3(-)>Cl(-) in fixed-bed column tests.
• Over 95% phosphate recovery was achieved upon regeneration with 4% NaCl at pH 7.
• Phosphate uptake capacity remained stable after 7 regeneration cycles.

Conclusions:

• The copper-loaded chelating resin (CR20-Cu) is a highly selective and effective material for phosphate removal from water.
• The resin's excellent regenerability and stable capacity make it a promising solution for wastewater treatment.
• This technology can help meet stringent environmental regulations for phosphate discharge.