Studied On The Influence Of Composite Flocculant Of MBFGA1 And PAC On Residual Aluminum

Bioflocculants, having good flocculating activity, are the metabolic products of the microorganism, which are safe, non-toxic, easily cultivated, and can be biodegraded. Its main components are amylases, glycoprotein, nucleic acid, proteinicsubstance. Since the advantages of using bioflocculants in both environmental safety and economic over some other inorganic flocculants and organic flocculants, great attention has been paid to explore the bioflocculants mechanism and to investigate their characteristicsinuse. As a result, it is of great value in the research of bioflocculant.Paenibacillus polymyxa GA1 was a bacterium with high bioflocculant producing rate which was screened out from soil by our lab. It could produce bioflocculant MBFGA1 with super ordinary flocculability and decolorizing property.The Central Composite Design, including five factors: pH, dosages of MBFGA1 and PAC, contact time and temperature, was employed to study the influence of composite flocculant of MBFGA1 and PAC on residual aluminum, with the flocculating rate and residual aluminum concentration as the targets response. With of determination coefficients (R2) equal to 0.8485 and 0.8025, respectively, which indicated that they all had a significant property. The results showed that contact time and temperature were the two key factors influencing the flocculating rate, and that dosages of MBFGA1 and PAC were the two key factors influencing residual aluminum concentration. The optimal adsorption conditions were pH 8.54, dosage of MBFGA1 111.02 mg·L-1, dosage of PAC86.22 mg·L-1, contact time 81.94 min and temperature 23.51℃, and under these conditions, the flocculating rate was 97.98% and the residual aluminum concentration was 136.45μg·L-1.FTIR analysis demonstrates that the group of -OH,C=O and C-O-C are main functional groups for removing Al.