Removal of polystyrene microplastics using biochar-based continuous flow fixed-bed column

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Microplastics pose significant environmental and health risks.
• Conventional water treatment plants struggle to remove microplastics effectively.

Purpose of the Study:

• To investigate the efficacy of banana peel biochar in a continuous flow system for microplastic removal.
• To optimize parameters influencing microplastic removal efficiency.

Main Methods:

• Synthesized biochar from banana peel via nitrogen-free slow pyrolysis.
• Evaluated microplastic removal in a continuous flow column.
• Systematically varied parameters: bed height, flow rate, concentration, and microplastic size.
• Characterized biochar properties and removal mechanisms.

Main Results:

• Achieved a peak removal efficiency of 92.16% for polystyrene microplastics.
• Optimal conditions: 6-cm bed height, 3-mL/min flow rate, 0.05 g/L concentration, 150-300 µm size.
• Removal efficiency inversely correlated with flow rate and directly with bed height.
• Removal mechanisms include adsorption, filtration, entanglement, and entrapment.

Conclusions:

• Banana peel biochar is a promising material for microplastic remediation.
• Adsorption and filtration are key removal mechanisms, enhanced by biochar's hydrophobic properties.
• This study offers a sustainable strategy for mitigating microplastic pollution.