Preparation and Flocculation Properties of Bioflocculant from Dewatered Sludge

Bioflocculant JT06 was extracted from dewatered sludge by ultrasonication,acetone precipitation and freezing desiccation.The preparation conditions and flocculation properties of the bioflocculant JT06 were studied.The results indicate that the optimal preparation conditions are 100 g/L sludge,15 min ultrasonication and two times volume of acetone.The high flocculation efficiency of kaolin suspension is achieved when the pH value is kept between 1 and 4,and the high flocculation rate can be reached in the absence of coagulation aid of metal cations.The different metal cations have different coa-gulation aids when the pH is above 4.There is a close relation between CaCl2 solution concentration and the flocculant dosage,and the higher the CaCl2 solution concentration is,the larger the optimal flocculant dosage is.