超声-碱破解剩余污泥的条件优化

剩余污泥水解是实现污泥减量化和解决污水处理厂生物脱氮除磷中碳源不足的重要途径。以浓缩池污泥为对象，通过正交实验对超声-碱联合处理条件进行优化，考察了污泥破解率、上清液C/N与C/P的变化，并进行经济性分析。结果表明，对污泥破解率、上清液C/N、C/P影响最大的3个因素分别为pH、声能密度、pH。综合考虑3者，得到最佳操作条件为，声能密度=1.5 W·mL⁻¹、超声时间=15 min、pH=10、碱处理时间=1.5 h，在此条件下，污泥VSS去除率可达35％左右，可以减少污泥处置的成本。上清液SCOD>7 600 mg·L⁻¹、C/N>30、C/P>60，可以制备高碳低氮磷的污泥上清液回流，在大规模应用中比外加碳源的方式要节约成本。本研究结果可为超声-碱破解污泥的实际工程提供参考。

Condition optimization of ultrasonic-alkali treatment of excess sludge

Excess sludge hydrolysis is an important way to reduce sludge and solve the carbon source shortage of biological nitrogen and phosphorus removal in sewage treatment plants. In this study, the combined ultrasound-alkali treatment was optimized by orthogonal experiments to optimize the sludge disintegration degree and the C/N, C/P of the supernatant, and the economic analysis was carried out. The results showed that the three factors with the greatest influence on sludge disintegration degree, supernatant C/N and C/P were pH, sound energy density and pH. Considering comprehensively, the optimal operating conditions are: sound energy density = 1.5 W·mL−1, ultrasonic time = 15 min, pH = 10, alkali treatment time = 1.5 h, and the sludge VSS removal rate can reach about 35%, which can reduce the cost of sludge disposal. Supernatant SCOD> 7 600 mg·L−1, C/N>30, C/P>60, can prepare high carbon, low nitrogen and phosphorus sludge supernatant to return, which is more cost-effective than adding carbon sources in large-scale applications. The results of this study can provide a reference for the actual engineering of ultrasound-alkali sludge disintegration.