Straw N-halamines: evaluation in single and multistage filtration systems

Area of Science:

• Materials Science
• Environmental Science
• Microbiology

Background:

• Cellulose, a sustainable biopolymer, is a potential platform for developing novel antimicrobial agents.
• N-halamines are a class of compounds known for their biocidal activity.
• Effective water purification methods are crucial for public health and environmental safety.

Purpose of the Study:

• To synthesize and evaluate new N-halamines based on cellulose from rice straw for antimicrobial applications.
• To assess the efficacy of these N-halamines in single and multistage filtration systems against bacteria and viruses.
• To compare the performance of cellulose-based N-halamines with existing synthetic biocidal polymers.

Main Methods:

• Extraction of cellulose from rice straw.
• Synthesis of two N-halamine compounds, I-Cl and II-Cl, using the modified cellulose.
• Testing antimicrobial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, and PRD1 bacteriophage (virus).
• Evaluation in single and multistage filtration systems with modifications to particle size and flow rate.

Main Results:

• N-halamine II-Cl demonstrated significant log reductions: 9 logs for E. coli in 2 hours, 9 logs for S. aureus in 1 hour, and 7 logs for PRD1 bacteriophage in 5 hours.
• Antimicrobial activity was confirmed in modified cellulose materials tested in filtration systems.
• The performance of the cellulose-based N-halamines was found to be comparable to synthetic biocidal polymers in similar water treatment scenarios.

Conclusions:

• Cellulose extracted from rice straw can be effectively functionalized into N-halamines with potent antimicrobial capabilities.
• These novel bio-based materials offer a promising sustainable alternative for water disinfection and purification.
• The developed N-halamine cellulose shows significant potential for use in advanced filtration systems to combat waterborne pathogens.