[Influencing Mechanism of Calcium Peroxide Pre-treatment on Dewatering Performance of Waste Activated Sludge].

The evolution of sludge filteration dewaterability, floc structure and hydrolytic kinetics with calcium peroxide oxidation pre-treatment was investigated in this study. The effect of sludge characteristics with combined process of ferrous ion and calcium peroxide was deeply analyzed and the result suggested that the sludge dewatering performance was improved first and then worsened after CaO addition. When the dosage was 20 mg·g, sludge reached its optimal dewaterability. At the same time, sludge was effectively dissolved and the floc structure became loose and broken with the increase of organic matters in the supernatant. Moreover, sludge solubilization process followed the pseudo-zero-order kinetic equation well and the reaction rate of sludge with CaO treatment was 15.2 mg·L·h. In addition, sludge floc lysis was enhanced by the treatment of ferrous ion and calcium peroxide oxidation, whilst sludge dewaterability was improved due to the reconstruction of sludge floc structure by the iron ions produced. This study provided theoretical basis for application of calcium peroxide pre-treatment and its combining technique in sludge treatment.