Fenton试剂对剩余污泥脱水性能的改善

Improvement of Excess Sludge Dewatering Performance with Fenton Reagent

研究了利用Fenton试剂调理城市污水处理厂剩余污泥,通过测定污泥毛细吸水时间(CST)、污泥比阻(SRF)和泥饼含水率来表征污泥脱水性能的变化,分别考察了污泥初始pH、H2O2投加量、H2O2/Fe2+、反应温度和反应时间对污泥调理效果的影响。综合考虑,确定Fenton调理污泥的最佳条件为:pH=3、抽滤脱水和离心脱水H2O2最佳投加量分别为3 g/L和9 g/L、H2O2/Fe2(+质量比)最佳范围为8～12、反应温度50℃、反应时间60 min。对污泥离心上清液中胞外聚合物(EPS)含量的研究表明,Fenton调理后污泥上清液中蛋白质和多糖含量有大幅升高,说明Fenton试剂能有效氧化破解EPS,从而提高污泥的絮凝性,改善污泥的脱水性能。Fenton氧化后污泥颗粒粒径变小,比表面积增大。

The conditioning of excess sludge by Fenton reagent was studied. The capillary suction time （CST）, the specific resistance to filtration （SRF） and the water content of sludge cake were measured to examine change of sludge dewatering performance. The effects of initial pH of sludge, H2O2 dosage, H2O2/Fe2＋ ratio, reaction time and temperature on sludge conditioning were investigated. The optimal condition for sludge conditioning was determined as follows： pH=3, H2O2 dosage of filtration and centrifugal dehydration was 3 g/L and 9 g/L respectively, H2O2/Fe2＋ ratio （mass ratio）=8-12, temperature T=50 ℃, and reaction time was 60 min. The research of EPS content in sludge supernatant showed that the protein and polysaccharide content significantly increased after conditioning by Fenton reagent, and it demonstrated that Fenton oxidation could effectively break EPS and improve the flocculation and dewatering performance of sludge. After Fenton oxidation, sludge particle size became smaller and the surface area increased.