Novel biodegradable flocculanting agents based on cationic amphiphilic polysaccharides.

Area of Science:

• Polymer Chemistry
• Colloid and Surface Science
• Environmental Engineering

Background:

• Clay dispersions are common in industrial wastewater.
• Effective flocculation is crucial for solid-liquid separation.
• Cationic polysaccharides offer potential as eco-friendly flocculants.

Purpose of the Study:

• To investigate the flocculation properties of novel cationic polysaccharides.
• To determine the influence of polymer structure on flocculation efficiency in clay dispersions.
• To elucidate the flocculation mechanisms involved.

Main Methods:

• Synthesis of cationic polysaccharides with varying N-alkyl substituents on a dextran backbone.
• Evaluation of flocculation performance using turbidimetry and zeta potential measurements.
• Analysis of floc size to understand aggregation behavior.

Main Results:

• Alkyl chain length critically affected optimum polymer dose and flocculation window width.
• Butyl substituents yielded the most effective flocculation, while octyl and dodecyl groups reduced efficiency.
• Charge density influenced residual turbidity, but molar mass had minimal impact.
• Zeta potential measurements indicated negative surface charge at optimal polymer dosage.

Conclusions:

• The study demonstrates the tunable flocculation properties of cationic polysaccharides based on alkyl chain length.
• Both patch and bridging mechanisms contribute to the flocculation of clay dispersions.
• Optimized cationic polysaccharides show promise for efficient clay flocculation in environmental applications.