Remarkably Enhanced Phosphate Sequestration from Waters by Biochar with High-Density Quaternary Ammonium Groups

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment

Background:

• Biochar is typically used for cationic pollutants.
• Phosphate removal from water is a significant environmental challenge.
• Developing efficient adsorbents for anionic pollutants is crucial.

Purpose of the Study:

• To fabricate a novel biochar (N-BC) for efficient phosphate removal.
• To investigate the adsorption performance and mechanism of N-BC for phosphate.
• To evaluate the reusability and practical application potential of N-BC.

Main Methods:

• Fabrication of N-BC by incorporating quaternary ammonium groups.
• Phosphate adsorption experiments at varying pH and concentrations.
• Analysis of adsorption kinetics, capacity, and mechanism.
• Column studies for continuous wastewater treatment.
• Regeneration studies using NaOH solution.

Main Results:

• N-BC demonstrated high phosphate adsorption efficiency (30 mg P/g) at pH 5.0.
• Effective phosphate removal occurred even in the presence of high chloride concentrations.
• The adsorbent was fully regenerated and reused without capacity loss.
• Column studies showed N-BC could treat 324 bed volumes before breakthrough.

Conclusions:

• N-BC offers a promising solution for phosphate purification from water.
• The study presents a new strategy for utilizing biochar for anionic pollutant removal.
• Quaternary ammonium groups are key to N-BC's phosphate sequestration ability.