Enhanced Capture Ability of Sludge-Derived Mesoporous Biochar with a Template-like Method

Area of Science:

• Environmental Science
• Materials Science
• Water Treatment

Background:

• Sewage sludge is a significant waste stream requiring sustainable management.
• Methylene blue (MB) is a common water pollutant requiring efficient removal methods.
• Developing novel adsorbents from waste materials is crucial for environmental remediation.

Purpose of the Study:

• To synthesize sewage sludge-derived mesoporous biochars (SS-MBCs) using cationic polyacrylamide (PAM+) as a template.
• To investigate the structural properties and methylene blue (MB) adsorption performance of SS-MBCs.
• To compare the efficacy of SS-MBCs with commercial activated carbon and other sludge-based adsorbents.

Main Methods:

• SS-MBCs were synthesized using a template-assisted method with cationic polyacrylamide (PAM+) and sewage sludge at high temperatures.
• Textural evolution, morphology, thermodynamic properties, and surface chemistry of SS-MBCs were analyzed.
• Adsorption kinetics and isotherms for MB removal were studied, and preparation factors were optimized.

Main Results:

• PAM+ templating resulted in well-developed textures and improved MB adsorption capacities of SS-MBCs.
• Increased specific surface area and oxygen functional groups (lactone) enhanced MB adsorption.
• Optimal performance was observed at pyrolytic temperatures above 800 °C, with PAM+ concentration and sludge dosage as key factors.
• Adsorption followed Langmuir isotherm model and pseudo-second-order kinetics.

Conclusions:

• SS-MBCs synthesized with PAM+ exhibit excellent methylene blue removal efficiency and adsorption capacity.
• These biochars outperform commercial activated carbon and other reported sludge-based adsorbents.
• The study demonstrates a promising method for valorizing sewage sludge into high-performance water treatment materials.