Fenton-絮凝联合调理对污泥脱水性能影响

Effects of Fenton-flocculation combined conditioning on sludge dewatering

为改善污泥脱水性能并比较不同调理方法的优劣,采用絮凝、Fenton氧化及Fenton-絮凝联合对城市污水处理厂剩余污泥进行调理。研究以滤饼含水率、污泥比阻(SRF)、上清液浊度、胞外聚合物(EPS)作为评价指标,综合考察试剂投加量、反应时间、污泥pH等因素对污泥脱水性能的影响及其最佳条件。结果表明:在H2O2、Fe2+的投加量分别为4 g/L、30 mg/L,Fenton反应时间为60 min时,Fenton氧化对污泥絮体的破解效果最佳。该最佳Fenton反应条件下进行污泥絮凝调理,投加CPAM 60 mg/L、调节初始pH为5,污泥调理效果最佳,使得滤饼含水率、上清液浊度、SRF分别降低了24.56%、42.12%、66.67%。Fenton-絮凝联合调理对于污泥脱水性能的改善显然优于单独絮凝调理。Fenton试剂可通过强氧化作用有效破解污泥絮体的EPS,进而有效降低污泥含水率;CPAM的絮凝作用使污泥比阻大大降低,提高了污泥脱水性能。

In order to improve the sludge dewatering performance and compare the advantages and disadvantages of different conditioning methods, flocculation, Fenton oxidation and Fenton-flocculation were used to condition the residual sludge in the municipal wastewater treatment plant. Filter cake moisture content, sludge specific resistance(SRF), supernatant turbidity, and extracellular polymer(EPS) were used as evaluation indicators, and the effects of dosage of the agent, reaction time, and pollution sludge pH and other factors on sludge dewatering performance were comprehensively examined for obtaining the optimal conditions. Results showed that Fenton oxidation on the optimal performance of cracking sludge flocculation by Fenton process was obtained at 4 g/L H2O2, 30 mg/L Fe2+, and Fenton reaction time 60 min. The sludge flocculation conditioning was performed under the optimal Fenton reaction conditions. Filter cake moisture content, supernatant turbidity, SRF were reduced by 24.56%, 42.12% and 66.67%, respectively at CPAM 60 mg/L and initial pH 5. Fenton-flocculation combined conditioning had obviously improved the dewatering performance of sludge better than flocculation conditioning alone. Fenton reagent could effectively break the EPS of sludge floc through strong oxidation, and then effectively reduce the sludge moisture content. The flocculation of CPAM greatly reduced the specific resistance of sludge and improved the sludge dewatering performance.