Optimized preparation and performance evaluation of a bifunctional chitosan-modified flocculant

Area of Science:

• Polymer Science
• Environmental Chemistry
• Water Treatment Technologies

Background:

• Growing diversity of sewage pollutants necessitates advanced water treatment agents.
• Improving efficiency and multi-functionality of water treatment agents are key research areas.
• Chitosan, a natural polymer, serves as a base for developing effective flocculants.

Purpose of the Study:

• To synthesize and optimize a novel chitosan-grafted copolymer, poly(CTS-g-AM-MAPTAC), using acrylamide (AM) and MAPTAC monomers.
• To enhance the solubility, flocculation, and bactericidal properties of the chitosan-based flocculant.
• To evaluate the performance of the synthesized poly(CTS-g-AM-MAPTAC) in wastewater treatment.

Main Methods:

• Graft copolymerization of chitosan with AM and MAPTAC monomers.
• Optimization of preparation conditions using response surface methodology (RSM).
• Evaluation of flocculation and sterilization efficiency, solubility, and biodegradability.

Main Results:

• Optimal preparation conditions determined: 6 mol L⁻¹ initiator concentration, 4 mass ratio of total monomer to chitosan, 25% monomer molar ratio, and 60 min illumination time.
• Optimized poly(CTS-g-AM-MAPTAC) exhibited high intrinsic viscosity (5.4965 dL g⁻¹) and grafting rate (220.34%).
• The synthesized flocculant demonstrated good solubility across varying pH, high turbidity removal, effective sterilization, good biodegradability, and low reagent consumption.

Conclusions:

• Poly(CTS-g-AM-MAPTAC) is a highly effective, multi-functional water treatment agent derived from chitosan.
• The optimized preparation method yields a superior flocculant with enhanced properties.
• This novel flocculant presents a promising, eco-friendly solution for complex wastewater treatment challenges.