Preparation of Microbial Flocculant MF-1 and Its Flocculation on Midcourse Wastewater in Papermaking Factory

A kind of aspergillus niger which was isolated from soil was inoculated with Czapek-Dox liquid medium. Controling the experimental conditions, microbial flocculant MF-1 was prepared. MF-1 was adopted for the treatment of midcourse wastewater in papermaking factory. The influence to the flocculation effect of the dosage of flocculant, addition of metal ions, temperature, pH value, and flocculant stirring strength was studied. The optimal flocculation condition was found to be flocculant dosage 60 mg/L, with Fe(III) as the coagulant aid, stirring at 250 rpm for 25 min at 60°C, with pH<;3. The removal rate of COD_Cr and turbidity can reach 71% and 92%, respectively. The efficiency was much higher than that of traditional flocculants.