Synthesis Optimization of a Hydrophobic Cationic Flocculant and its Mechanism Study in Clay Suspension: Experiment and Simulation
Abstract
To mitigate the negative environmental impact of flocculants while improving their efficiency, developing eco-friendly and effective flocculants is essential. In this study, a cationic hydrophobic flocculant (GgB) was synthesized using natural organic polymer guar gum and the surface-active monomer N-benzyl-2-(methacryloyloxy)-N, N-dimethylethan-1-aminium chloride via ultraviolet-initiated polymerization. The synthesis conditions were optimized through response surface methodology to maximize the flocculant's performance. The monomer was found to be most likely grafted onto the 3rd hydroxyl group of the guar gum galactose branched chain using Raman spectroscopy, elemental analysis, nuclear magnetic resonance X-ray photoelectron spectroscopy, scanning electron microscopy, and density functional theory simulation. This flocculant was subsequently applied to the flocculation-filtration processes of montmorillonite and kaolin particles in wastewater, which revealed the flocculation efficiency of GgB on montmorillonite suspension was higher than kaolinite at the same dose, but more effective for kaolinite dewatering. Mechanistic studies and molecular dynamics simulations indicated that the cooperation between charge neutralization, hydrophobic association, and adsorption bridging synergistically contributed to clay particle flocculation, and hydration of clay minerals has a significant effect on GgB, with electrostatic interactions dominating in montmorillonite systems and van der Waals forces prevailing in kaolinite systems. Overall, this research highlights the synthesis of eco-friendly flocculant and elucidates its mechanisms in clay particles, offering critical insights for the design and application of environmentally sustainable flocculants in wastewater treatment processes.
Recommended Citation
N. Li et al., "Synthesis Optimization of a Hydrophobic Cationic Flocculant and its Mechanism Study in Clay Suspension: Experiment and Simulation," Journal of Environmental Chemical Engineering, vol. 13, no. 2, article no. 115486, Elsevier, Apr 2025.
The definitive version is available at https://doi.org/10.1016/j.jece.2025.115486
Department(s)
Mining Engineering
Keywords and Phrases
Clay mineral; Graft copolymer; Guar gum; Hydrophobic cationic flocculant; Molecular simulation; Photoinitiation
International Standard Serial Number (ISSN)
2213-3437
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Elsevier, All rights reserved.
Publication Date
01 Apr 2025
