Optimization and characterization of polysaccharide-based bioflocculant produced by Paenibacillus elgii B69 and its application in wastewater treatment

► A new bioflocculant from Paenibacillus elgii B69 was purified and characterized. ► The maximum biofolcculant production was 25.63 g/L after optimized by RSM. ► It had high flocculating activities to all the tested pollution in wastewater. ► It had great potential for water pretreatment in industry.