Dye wastewater treatment by chitosan / bauxite composite flocculant

Simulated decoloration treatment of dye wastewater from Reactive Brilliant Red X3B and Vat Scarlet R was performed with chitosan /bauxite composite flocculant,and the effects of dosage of composite flocculant,pH,stirring speed and stirring time on decoloration ratio were investigated.The results showed that chitosan /bauxite composite flocculant has a better performance in decoloration of wastewater than chitosan or bauxite used alone.When concentration of dye 100 mg /L,pH = 5,and dosage of composite flocculant 1.25 g /L,three kinds of mass ratios of chitosan-bauxite achieve decoloration ratio for X3B up to 75%,90% and 97% respectively.When dosage of composite flocculant is 0.5 g /L under the same conditions,the three kinds of mass ratios of chitosan-bauxite achieve decoloration ratio for R up to 100%.Bauxite has very good recyclic use property.The decoloration ratio of X3B with the 3rd recycled composite flocculant of bauxite still achieves above 94%.