Fe^(2+)/S_2O_8^(2-)氧化法改善污泥脱水性能研究

Improvement of Sludge Dewatering Performance by Fe^(2+)/S_2O_8^(2-) Oxidation Process

采用亚铁离子活化过硫酸盐调理污泥,探究其对污泥脱水性能的影响。以CST降低率和污泥沉降比为评价指标,借助响应面法的Box-Behnken试验设计,考察各实验因素对污泥脱水性能的交互影响,确定最优工艺条件,并对脱水机理进行分析。结果表明:Na_2S_2O_8投加量为125.24 mg/g DS,Fe^(2+)投加量为32.86 mg/g DS,pH值为6.8时,CST降低率达到89.35%,污泥脱水性能最好,三因素交互作用明显。对调理前后污泥样品的分析测试结果表明,该过程主要是Fe^(2+)活化激发S_2O_8^(2-)产生强氧化自由基SO_4^-·,将团聚紧密的污泥絮体破解为碎片状,形成孔洞结构,附着在污泥颗粒上的胞外聚合物发生溶解,这些变化有利于结合水的脱除。

The application of persulfate activated by ferrous ion in conditioning of sewage sludge was studied to improve the sludge dewatering performance.Through the Box-Behnken test design,the influence of experimental factors on the dewatering performance of sludge was investigated and the optimum process conditions were determined,using CST reduction rate as the evaluation index,and the dehydration mechanism was analyzed.The results showed that when the Na2S2O8 dosage was125.24 mg/g DS,the Fe2＋ dosage was 32.86 mg/g DS,and the p H value was 6.8,the CST reduction rate reached a maximum of89.35%,and the three factors interaction was remarkable.The test results of sludge samples showed that Fe2＋activates S2O82-to produce strong oxidized radicals-SO4-·,the agglomerated sludge flocs are broken into fragments to form pore structure,and the extracellular polymeric substances attached to the sludge particles are dissolved,which are conducive to the removal of bound water.