绿色纳米铁/铈联用过碳酸钠改善厌氧消化污泥脱水性能的研究

Improvement of dewatering performance of anaerobically digested sludge by green nano iron/cerium combined with sodium percarbonate

采用绿色合成的纳米铁/铈(Fe/Ce-NPs)联用过碳酸钠(SPC)对厌氧消化(AD)污泥进行调理,考察了Fe/Ce-NPs投加量、SPC投加量、调理时间、初始pH对AD污泥脱水性能的影响。通过Box-Behnken响应面试验设计对前3个单因素进行优化,以确定其交互作用和最优解。结果表明,构建了响应值为含水率的二次模型,模型的P<0.05、R^(2)=0.9899>0.95,模型拟合效果显著。根据响应值的分布特点,确定AD污泥脱水的最佳条件为:Fe/Ce-NPs投加量为41.3 mg/(g·TSS)、SPC投加量为308 mg/(g·TSS)、反应时间为43 min,最佳条件下泥饼含水率降至73.6%,与模型预测值相差仅0.118%,具有较高的精确度。同时,对厌氧消化(AD)污泥的脱水机理进行了分析。

The anaerobically digested sludge is conditioned by using environmentally friendly synthesized nano iron/cerium(Fe/Ce-NPs)in conjunction with sodium bicarbonate.This study aims to investigate the influences of Fe/Ce-NPs dosage,sodium bicarbonate dosage,conditioning time,and initial pH on the dewatering performance of sodium bicarbonate sludge.The first three single factors are optimized through a Box-Behnken response surface experimental design to determine their interaction and the optimal solution.A quadratic model is established with the moisture content as the response variable.The model has a P<0.05,R^(2)=0.9899>0.95,indicating a significant fitting effect.According to the distribution characteristics of the response variables,the optimal conditions for dewatering of anaerobically digested sludge are determined as follows:Fe/Ce-NPs dosage is 41.3 mg/(g·TSS),sodium percarbonate dosage is 308 mg/(g·TSS),and the reaction time is 43 minutes.Under these optimal conditions,the moisture content of the sludge cake drops to 73.6%,representing a 0.118%of deviation from the predicted model value.Additionally,a comprehensive analysis is given on the dewatering mechanism for anaerobically digested sludge.