生物沥浸联合类Fenton作用对污泥脱水性能的改善

Improvement of sludge dewaterability using bioleaching combined with a Fenton-like reaction

为了解生物沥浸促进下的类Fenton调理对污泥脱水性能的影响,采用序批式恒温培养法,以比阻（SRF）、毛细吸水时间（CST）、过滤时间（TTF）和上清液中胞外聚合物（EPS）组分含量等指标,比较生物沥浸、Fenton氧化以及生物沥浸联合类Fenton氧化3种调理方法对污泥脱水速率和脱水程度的影响,并探讨其调理机制.结果表明,污泥经过生物沥浸联合类Fenton氧化调理后,比阻和毛细吸水时间分别从14.0×10^（12） m/kg和24 s下降到0.178×10^（12） m/kg和7.7 s,脱水性能较单独生物沥浸提高80.0%,与单独Fenton相比提高90.6%.此外,H_2O_2投加量对污泥的脱水效果具有重要影响,在本研究条件下最佳H_2O_2投加量是20 mg/g DS（干物质）.因此,生物沥浸联合类Fenton作用可显著改善污泥脱水性能,EPS释放、Fe^（3＋）絮凝和大量结合水转化为自由水是促进污泥脱水的主要原因.

To investigate the inf luence of Acidithiobacillus ferrooxidans-based bioleaching combined with a Fenton-like reaction on sludge dewaterability, Fenton oxidation and bioleaching were performed using separate and combined conditioning via batch experiments. Several parameters, such as specific resistance to filtration（SRF）, capillary suction time（CST）, and the time to filter（TTF）, were used to evaluate the dewatering performance. The contents and composition of extracellular polymer substances（EPS） and the sludge particle size were also measured to analyze the possible conditioning mechanism. After bioleaching combined with the Fenton-like reaction, SRF and CST decreased from 14.0 × 10^（12） to 0.178 × 10^（12） m/kg and from 24 to 7.7 s, respectively. The results indicated that the optimal H_2O_2 dosage was 20 mg/g DS（dry substance）.Combined conditioning using Fenton oxidation and bioleaching proved to be more effective to improve sludge dewaterability compared with traditional Fenton oxidation or bioleaching conditioning. The dosage of H_2O_2 had a marked influence on sludge dewaterability during conditioning by bioleaching combined with the Fenton-like reaction. In conclusion, a combination of bioleaching and Fenton-like reaction can improve sludge dewaterability, and EPS dissolution, Fe^（3＋） coagulation, transformation of bound water into free water may be responsible for improvement of sludge dewaterability.