次氯酸钠与亚铁对污泥破解及脱水效果的影响

采用次氯酸钠（NaClO）与亚铁（Fe（II））结合处理污泥以提高污泥破解和脱水效能，考察了NaClO和Fe（II）投加量的影响，并通过定量和定性分析污泥中胞外聚合物质（EPS）的迁移转化，确定NaClO和Fe（II）对污泥脱水和破解的机制.试验结果表明，NaClO和Fe（II）投加量（以干泥固体计）分别为44 mg·g^-1和66 mg·g^-1时，污泥毛细吸吮时间（CST）从原泥的112 s下降到66.3 s.同时，NaClO/Fe（II）处理污泥能够使上清液中化学需氧量（COD）显著升高，并使污泥中紧密束缚型EPS（TB-EPS）和松散束缚型EPS（LB-EPS）转化成溶解性EPS（S-EPS），导致S-EPS的溶解性有机碳（DOC）含量升高，而LB-EPS和TB-EPS的DOC含量降低.此外，NaClO/Fe（II）还能使污泥中有机物质矿化，使3种EPS中蛋白质类和腐殖酸类物质减少.NaClO和Fe（II）能够改善污泥脱水性能，强化污泥破解效果，利于污泥后续的处理处置.

Effects of sodium hypochlorite and ferrous iron on sludge disintegration and dewatering

The effects of NaClO and Fe(II) dosages on sludge disintegration and dewatering properties were investigated, and the underlying mechanism of this NaClO/Fe(II) conditioning was explored by analyzing the transformation of sludge extracellular polymeric substance (EPS). results showed that when NaClO and Fe(II) dosage were 44 mg·g^-1 and 66 mg·g^-1 drying solid, respectively, the capillary sucking time (CST) decreased from 112 s to 66.3 s for raw sludge. Moreover, chemical oxygen demand (COD) significantly increased in conditioned sludge supernatant, and tightly bound EPS (TB-EPS) and loosely bound EPS (LB-EPS) were transformed into soluble EPS (S-EPS) under NaClO/Fe(II) conditioning. As a result, dissolved organic carbon (DOC) of S-EPS increased while DOC of TB-EPS and LB-EPS decreased. In addition, the organic substances in sludge were mineralized by NaClO/Fe(II), resulting in the reduction of the protein and humic substances in the three EPSs. These results suggest that NaClO/Fe(II) could improve sludge dewaterability and disintegration efficiency, which is benefit to the subsequent sludge treatment and disposal.