Continuous Phosphate Removal and Recovery Using a Calcium Silicate Hydrate Composite Monolithic Cryogel Column

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Phosphate removal from water is crucial for preventing eutrophication.
• Conventional methods face challenges in efficiency and environmental impact.
• Development of sustainable and practical adsorbents is needed.

Purpose of the Study:

• To develop and evaluate a monolithic cryogel adsorbent (Cry-CSH) for continuous phosphate removal.
• To investigate the effects of operational parameters on adsorption efficiency in a flow system.
• To assess the performance of Cry-CSH in real wastewater effluent.

Main Methods:

• A novel monolithic cryogel adsorbent (Cry-CSH) composed of starch and calcium silicate hydrate was synthesized.
• Phosphate adsorption was studied in a continuous flow column system.
• The influence of flow rate, initial phosphate concentration, and adsorbent height was investigated.
• Adsorption data was modeled using Adams-Bohart, Thomas, and Yoon-Nelson models.
• The Cry-CSH system was tested on real wastewater effluent from a treatment plant.

Main Results:

• The Cry-CSH adsorbent demonstrated effective phosphate removal in a continuous flow system.
• Adsorption efficiency decreased with increased flow rate and initial phosphate concentration.
• Increased adsorbent height significantly enhanced column performance.
• The Adams-Bohart model best described the initial adsorption kinetics.
• The system achieved 94.61% phosphate removal from municipal wastewater effluent.

Conclusions:

• The monolithic Cry-CSH cryogel is a practical and green adsorbent for continuous phosphate removal.
• Adsorbent height is a key factor in optimizing column performance.
• The Cry-CSH system shows high potential for treating real wastewater and mitigating eutrophication.