Near-Complete Phosphorus Recovery from Challenging Water Matrices Using Multiuse Ceramsite Made from Water Treatment...

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment Technologies

Background:

• Water treatment residual (WTR) poses significant management challenges and costs for water treatment plants.
• Aluminum-salt WTR (Al-WTR) is a common waste product requiring sustainable management strategies.
• Phosphate pollution in water bodies necessitates efficient recovery methods.

Purpose of the Study:

• To develop a novel ceramsite material (ASC) from Al-WTR for phosphate recovery.
• To evaluate the adsorption capacity and efficiency of ASC for phosphate removal from challenging water matrices.
• To assess the economic viability and environmental benefits of ASC as a phosphate adsorbent.

Main Methods:

• Transformation of Al-WTR into ceramsite (ASC) through a specific process.
• Characterization of ASC, including specific surface area (SSA) measurement.
• Phosphate adsorption experiments across a wide pH range and in the presence of competing ions and humic acid.
• Testing ASC performance with real municipal wastewater at low temperatures.
• Economic analysis comparing ASC with existing materials.

Main Results:

• ASC exhibited a high SSA (70.53 m²/g) and phosphate adsorption capacity (47.2 mg P/g).
• Over 94.9% phosphate recovery was achieved across pH 3-11, with sustained performance against competing anions and humic acid.
• Simultaneous phosphate (>97.1%) and COD (71.2%) removal was demonstrated in real municipal wastewater at 10°C.
• ASC showed potential for repurposing after phosphate saturation, such as for landscaping or soil amendment.

Conclusions:

• ASC is an eco-friendly and cost-effective adsorbent for phosphate recovery from challenging waters.
• The developed material offers a promising route towards a circular economy in the water sector.
• ASC presents a competitive alternative to conventional materials like clay-based ceramsite and biochar.