Preparation and characteristics of bioflocculant from excess sludge

In this study, the feasibility of bioflocculant prepared from excess sludge to reduce its production costs and carve out a new way to attain bioflocculant was investigated. Three reagents were used to disintegrate excess sludge including alkali, acid and oxyful. Results showed that the performance of alkali treatment was the best. The flocculating rate of the prepared bioflocculant by the alkali and acid treatment for kaolin clay (5g/L) was 92.6%, 88.5% respectively. The prepared influence factors such as alkali dosage and treatment time were researched. The optimal conditions were 4 g alkali dosage and 30min treatment time for 100mL sludge suspension. Under these conditions, the flocculating rate of kaolin clay was 92.6%. The major component of purified bioflocculant was found to be polysaccharide. Infrared spectrum analysis showed the presence of hydroxyl and acylamino groups in the bioflocculant.