Synthesis and properties of xanthan gum-acrylamide-carboxymethyl cellulose ternary anionic flocculants

Natural polymer based flocculants are prospective in water treatment on account of their advantages of wide source, simple operation process and ecological safety. However, its flocculation performance and cost effectiveness are usually not as satisfactory. In this work, xanthan gum-acrylamide-carboxymethyl cellulose (XAC) ternary anionic flocculant was synthesized with hydrothermal copolymerization. The polymerization conditions of raw material ratio, initiator dose, copolymerization time and reaction temperature were optimized by flocculation tests. The decolorization ratio of 82.9 % was obtained with XAC dosage of 35 mg/L for the 100 mg/L crystal violet aqueous solution. The as-prepared flocculants showed super decolorization ability and fast flocculation kinetics. The flocculation mechanism includes charge neutralization and bridging effects. More importantly, the operating expense of XAC is approximately 50 % of traditional polyacrylamide flocculant. In virtues of ecofriendliness, superior flocculation capacity and low expense, XAC flocculants show great promise for sewage treatment and open up a novel area for the natural polymer utilizations.