Polyacrylamide grafted cellulose as an eco-friendly flocculant: Efficient removal of organic dye from aqueous solution

The efficient and safe flocculation of colored wastewaters from textile and leather industries is of great significance for natural environment and human health. In this work, an eco-friendly bamboo pulp cellulose grafting ployacrylamide (BPC-g-PAM) flocculant was synthesized and employed to remove organic dyes from dye solutions by flocculation. The flocculation performance of the synthesized BPC-g-PAM was evaluated by chroma and turbidity removals of a series of cationic and disperse dye solutions. A L₉(3⁴) orthogonal experiment was designed to optimize the flocculation process of the BPC-g-PAM. The positive results showed that, the BPC-g-PAM exhibited an excellent flocculation performance to organic dye solutions. The average decolorization rate reached 96.7 % and the chroma could be reduced to 5° or even lower for the disperse dye solutions. The mechanism of the BPC-g-PAM flocculation to disperse dyes was investigated and determined as chemical adsorption kinetics. Furthermore, the eco-friendly BPC-g-PAM also held an excellent biodegradability of 66.5 % at 45 d and 67.6 % at 90 d in soil extracting solution, which were far higher than the corresponding data of the commercial PAM.