Production and flocculating performance of sludge bioflocculant from biological sludge

X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectra showed that amino and hydroxyl groups were present in the bioflocculant molecules. More amine group existed in the bioflocculant PSB-2 relatively. The amino group was believed to play an important role in flocculation. The experiment of zeta potential measuring indicated that the charge neutralization contributed to flocculation process. Flocculating mechanism investigation reveals that the sludge bioflocculant caused kaolin suspension instability by means of charge neutralization firstly and then promoted the aggregation of suspension particles by adsorption and bridge.