Solving urban water microplastics with bacterial cellulose hydrogels: Leveraging predictive computational models

Area of Science:

• Environmental Science
• Materials Science
• Biotechnology

Background:

• Microplastic (MP) pollution is a significant environmental concern, with wastewater treatment plants (WWTPs) identified as a major source.
• Sustainable and effective methods for MP removal are urgently needed in water treatment.

Purpose of the Study:

• To develop and evaluate bacterial cellulose (BC) hydrogels derived from waste as bioflocculants for microplastic removal.
• To investigate the influence of various operational parameters on the flocculation efficiency of BC hydrogels for MPs.

Main Methods:

• BC waste was processed into hydrogels and tested for microplastic flocculation under diverse conditions.
• Response surface methodology was employed to model and optimize the flocculation process.
• Characterization techniques included UV-Vis, ATR-FTIR, IGC, water uptake assays, fluorescence, and scanning electron microscopy.

Main Results:

• BC hydrogels demonstrated high efficiency in hetero-aggregating MPs, even at exceptionally high concentrations (88.6% flocculation at 2 g/L).
• Optimal flocculation was influenced by BC:MPs ratio and hydrogel grinding times, with short exposure times (5 min) being sufficient.
• The microporous structure of the BC hydrogel was identified as key to its potent bioflocculant activity, outperforming commercial alternatives.

Conclusions:

• Waste-derived BC hydrogels are highly effective and circular bioflocculants for microplastics.
• These findings present a promising, sustainable solution for MP removal in wastewater treatment applications.