An Eco-friendly One-Step Synthesis of Dicarboxyl Cellulose for Potential Application in Flocculation

A simple one-step and homogeneous synthesis method of dicarboxyl cellulose for the flocculant application is developed via Schiff base route using the cellulose from Phyllostachys heterocycla. The bamboo pulp cellulose is dissolved in NaOH–urea solution and oxidized as dialdehyde cellulose by NaIO4, which is continuously reacted with the residual urea and NaOH in the original reaction system to synthesize dicarboxyl cellulose. This one-step method greatly reduces the complexity and heterogeneity of the traditional two-step synthesis procedure, and avoids greatly the environmental pollution caused by the cellulose solvent. The dicarboxyl cellulose is characterized by Fourier transform infrared spectroscopy and X-ray diffraction spectroscopy, which exhibits an excellent coagulation–flocculation capability to kaolin suspension with a turbidity removal of 99.5%.