Effects of Potassium Ferrate-Walnut Shell Pretreatment on Dehydration Performance of Residual Sludge

Abstract Sludge dehydration is not only the primary part in sludge reduction, but also a difficult point in sludge treatment and disposal, while the high moisture content of the sludge will also limit its resource utilization. In this paper, the strong oxidizing property of potassium ferrate was used to treat the residual sludge, and walnut shells are used as a skeleton builder to obtain the dehydrated sludge that can be recycled. The disintegration degree of extracellular polymer of sludge (EPS), the moisture content of the sludge, and the specific resistance of sludge (SRF) were investigated to explo re the effects of potassium ferrate-walnut shell pretreatment on sludge dehydration performance. The experimental results show that the optimal dosages of potassium ferrate and walnut shells are 60 mg/gDS and 0.8 g/gDS, respectively, and the moisture content and SRF of the sludge after pretreatment reach the lowest values of 70.2% and 1.107×1011 m/kg, which greatly improves the dehydration performance compared with the individually treated potassium ferrate and walnut shells, and provides the new ideas and methods for sludge dehydration.