Dewaterability of five sewage sludges in Guangzhou conditioned with Fenton's reagent/lime and pilot-scale experiments using ultrahigh pressure filtration system. (1st November 2015)

• Record Type: Journal Article
• Authors: Liang, Jialin; Huang, Shaosong; Dai, Yongkang; Li, Lei; Sun, Shuiyu
• Is Part Of: Water research. Volume 84(2015)
• Page Start: 243
• Page End: 254
• Publication Date: 2015-11-01
• Subjects: Sewage sludges -- Dewaterability -- Fenton's reagent -- Lime -- Ultrahigh pressure filtration; DS dry solids content -- PSs polysaccharide -- PNs protein -- RS raw sludge -- CST capillary suction time -- DSC differential scanning calorimetry -- EPS extracellular polymeric substances -- SEM scanning electron microscope -- SRF specific resistance to filterability -- TOC total organic carbon -- TSS total suspended solids -- VSS volatile suspended solids -- SCOD soluble chemical oxygen demand -- TCOD total chemical oxygen demand -- WWTPs wastewater treatment plants -- VSS/TSS% organic matter contents; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2015.07.041
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Sludge conditioning with Fenton's reagent and lime is a valid method for sludge dewatering. This study investigated the influence of different organic matter content sludge on sludge dewatering and discussed the main mechanism of sludge conditioning by combined Fenton's reagent and lime. The results indicated that the specific resistance to filterability (SRF) of sludge was reduced efficiently by approximately 90%, when conditioned with Fenton's reagent and lime. Through single factor experiments, the optimal conditioning combinations were found. In addition, the relationship between VSS% and consumption of the reagents was detected. Furthermore, it was also demonstrated that the SRF and filtrate TOC values had a significant correlation with VSS% of sludge (including raw and conditioned). The main mechanism of sludge dewatering was also investigated. Firstly, it revealed that the dewaterability of sludge was closely correlated to extracellular polymeric substances (EPS) and bound water contents. Secondly, the results of scanning electron microscopy (SEM) stated that sludge particles were to be smaller and thinner after conditioning. And this structure could easily form outflow channels for releasing free water. Additionally, with the ultrahigh pressure filtration system, the water content of sludge cake conditioned with Fenton's reagent and lime could be reduced to below 50%. Moreover, the economic assessment shows that Fenton's reagent and lime combined with ultrahigh pressure filtration system can be an economical and viable technology for sewage sludge dewatering. Finally, three types of sludge were classified: (1) Fast to dewater; (2) Moderately fast to dewater; (3) Slow to dewater sludge. Graphical abstract: Highlights: An SRF reduction efficiency of > 90% was achieved with Fenton's reagent and lime. Conditioners released extracellular polymeric substances and bound water in sludge. Ultrahigh pressure filtration system was used in pilot-scale experiments. Our novel mechanistic models will allow more intuitive dewatering of sludge.