Study on preparation and application of a novel flocculant based on waste mulberry branch

Key words: 
• mulberry branch /
• flocculant, microwave /
• hexadecyl trimethyl ammonium bromide /
• pulp wastewater /

Abstract: Waste mulberry branch and hexadecyl trimethyl ammonium bromide (CTAB) were used to prepare a novel flocculant (GXSZ) by microwave irradiation. The optimal conditions of preparation of the flocculant were determined. The flocculant was used to treat pulp wastewater. The result shows that the optimal conditions of preparation of flocculant are as follows: the concentration of sodium hydrate is 8%, alkalization temperature is room temperature, alkalization time is 30 min, dosage of initiator Fe2+/H2O2 is 14 mmol/L, the mass ratio of mulberry branch to CTAB is 1∶1, the microwave power is 500 W, reaction temperature is 90℃ and reaction time is 60 min. The flocculant prepared under optimal technology conditions has distinct flocculation efficiency for pulp wastewater. When the pH value of pulp wastewater is 10, the dosage of the flocculant GXSZ is 100 mg/L, the removal rate of COD and turbidity reaches to 48.2% and 81.4%, respectively. As for treating pulp wastewater, the performance of the flocculant GXSZ is superior to the aluminum chloride，and is comparative to polymerized aluminum chloride, but the dosage of the flocculant GXSZ is significantly lower than that of aluminum chloride and polymerized aluminum chloride.