过氧化钙预处理对活性污泥脱水性能的影响机制

本研究采用过氧化钙对活性污泥进行预处理,深入分析了调理过程中污泥过滤脱水性能、絮体结构以及反应动力学的变化特性,探讨了亚铁离子协同过氧化钙处理对污泥特性的影响.结果表明,经过CaO_2处理后,污泥的过滤脱水性能先改善后恶化,当投加量(以TSS计)为20 mg·g~(-1)时,污泥的过滤脱水效果达到最佳.同时,污泥絮体结构变得疏松破碎,其上清液有机物浓度出现了明显的上升,污泥得到了有效裂解.污泥溶解反应过程遵循零级反应动力学模型,反应速率常数为15.2mg·L~(-1)·h~(-1).此外,亚铁离子和CaO_2协同处理可以进一步强化污泥中大分子有机物的裂解释放,同时,反应过程中形成铁离子的絮凝作用可以实现污泥絮体结构的重建,从而改善污泥过滤脱水性能.该研究成果为CaO_2及其联用处理技术在污泥处理过程中的应用提供了必要的理论依据.

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 CaO₂ addition. When the dosage was 20 mg·g^-1, 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 CaO₂ treatment was 15.2 mg·L^-1·h^-1. 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.