热碱预处理对高含固剩余污泥厌氧消化的影响及其动力学研究

Influence of thermal-alkaline pretreatment on higher solid containing excess sludge anaerobic digestion and the kinetic study

以高含固剩余污泥为研究对象,考察不同碱投加量下热碱联合预处理对剩余污泥溶胞效果和厌氧消化性能的影响,并运用3种动力学模型对剩余污泥生物化学产甲烷潜力过程进行模拟。结果表明,热碱联合预处理有助于促进剩余污泥的溶胞效果,并且随着碱投加量的增加,溶胞效果不断增强,当碱投加量为80mg/g(单位质量SS的NaOH投加量计)时,COD、氮、磷的溶出量均达到最大值,分别为58 622.2、1 792.8、790.3mg/L,溶出率分别为54.9%、45.7%、37.6%。热碱联合预处理可有效改善剩余污泥厌氧消化性能,但碱投加量过大时对可能对产甲烷过程带来抑制作用,碱投加量为60mg/g时剩余污泥厌氧消化的累积产甲烷量最大,为158.9mL/g,较不进行热碱联合预处理的空白组(106.5mL/g)高49.2%。3种动力学模型中,锥体模型对厌氧消化产甲烷过程的拟合效果最好,不同处理条件下模型拟合相关系数R^2均在0.990以上,该模型可准确预测最终的累积产甲烷量,预测误差均在2%以下。

In this paper,the excess sludge with higher solid content was selected as research object,and the disintegration and anaerobic digestion of the excess sludge after thermal-alkaline pretreatment under different alkalinedosage were studied.Biochemical methanogenic potential(BMP)of the pretreated excess sludge was simulated by three kinetic models.The results showed that the excess sludge was disintegrated after thermal-alkaline pretreatment and the effect of disintegration was enhanced with the increasing of alkaline dosage.When the alkaline dosage was 80 mg/g(counted by NaOH dosage per unit mass of sludge SS),the maximum COD,nitrogen and phosphorous solubilization of 58 622.2,1 792.8,790.3 mg/L was achieved with the solubilization rate was 54.9%,45.7% and37.6%respectively.The anaerobic digestion of excess sludge was improved by thermal-alkaline pretreatment,while the methane production process was inhibited under excessive alkaline dosage.When the alkaline dosage was 60 mg/g,the maximun methane production was 158.9 mL/g and 49.2% higher than that of the control test(without thermal-alkaline pretreatment,106.5 mL/g).The Biochemical methanogenic production data was simulated by three kinetic models,and Cone model achieved the best simulation performance,the fitting coefficient R^2 of different test was all above 0.990.By using which,the final methane production was accurately predicted,with the prediction errors between measured value and predicted value were all under 2%.