Highly Charged Cellulose Nanocrystals Applied as A Water Treatment Flocculant

Abstract

Various cellulosic materials have replaced petroleum-derived polymers, offering natural and sustainable alternatives. Among them, cellulose nanocrystals ({CNC}) feature an easily modifiable surface, enabling the exploration of a wide spectrum of applications. In this work, the quaternary agent 3-chloro-2-hydroxypropyltrimethylammonium chloride ({CHPTAC}) was used as a cationic graft on {CNCs}, to form a novel water treatment flocculant. The resulting material was chemically and structurally characterized by the determination of Zeta potential; degree of substitution by elemental analysis; hydrodynamic size by dynamic light scattering ({DLS}) and infrared spectroscopy with Fourier Transform Infrared ({FT}-{IR}); and X-ray diffraction ({XRD}). The flocculation capacity of cationic cellulose nanocrystals ({CNC}-{EPTMAC}) was evaluated in a jar test filled with an 0.25 wt.% silica ({SiO}2) suspension. {CNC}-{EPTMAC} proved to be an effective water treatment flocculant, reducing turbidity by up to 99.7% at a concentration of only 2 ppm. This work demonstrates a natural and environmentally sustainable alternative to homologous commercial flocculants.