Effect of polyamine flocculant types on dye wastewater treatment

Linear, branched, and grafted polyamine flocculants were synthesized and applied for dye wastewater treatment. The effect of polyamines on color removal was investigated by comparing two treatments: (i) alum alone and (ii) alum/polyamine in combination. Compared to alum alone treatment, the use of polyamine flocculants in combination with alum was highly efficient in color and turbidity removal. Addition of a small amount of polyamine (40 mg/L) reduced alum dosage by 50% while improving color removal efficiency by 20%. Branched polyamines were more efficient than grafted polyamines presumably because branched polyamine has higher charge density than grafted polyamine. Our results indicate that the use of alum/polyamine system is beneficial in dye wastewater treatment. The effects of polyamine flocculants on total organic carbon removal and zeta potential were also discussed.