Effects of potassium permanganate conditioning on dewatering and rheological behavior of pulping activated sludge: mechanism and feasibility

摘要: The difficulties in sludge dewatering are associated with the high organic content, colloidal materials solids and hydrophilicity of extracellular polymeric substances (EPS). Based on principle advanced oxidation processes, waste pulping activated was subjected to potassium permanganate (KMnO4) pretreatment then influence mechanism were comprehensively investigated present study. At lower KMnO4 dosage, changes physicochemical rheological characteristics that: (1) as disintegration degree increased, total extractable EPS increased bound water released; (2) behavior showed that yield stress viscosity decreased while flowability positive thixotropic weakened; (3) particle size microscopic structure changed insignificantly. These resulted damaging gel-like environment making surface floc stripped but did not completely induce breakage a result redox potential. Thus, dewaterability improved optimum dosage 16 g kg−1 dry solid. On perspective environmental safety, conditioning is feasible.