Performance and mechanism of sludge dewaterability enhanced by potassium ferrate pretreatment and calcium chloride addition

Journal of Water Reuse and Desalination

Jing, Zhaoqian¹  Liu, Yali¹  Wang, Zheng¹  Kang, Xiaorong²  Li, Xin³ 

[1]School of Civil Engineering, Nanjing Forestry University, Nanjing 210037, China

[2]School of Civil Engineering, Yancheng Institute of Technology, Yancheng 224051, China

[3]School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China

关键词: calcium chloride;    CST;    excitation-emission matrix;    sludge potassium ferrate;    waste activated sludge;   

DOI  :  10.2166/wrd.2016.147

学科分类：工程和技术（综合）

来源: IWA Publishing

【 摘 要 】

The potential benefits and mechanisms of potassium ferrate pretreatment and calcium chloride addition on sludge dewaterability were investigated in this study. The capillary suction time (CST) was used to evaluate sludge dewaterability. Results indicated that potassium ferrate of 0.1 g/g total solids (TS) and calcium chloride of 0.4 g/g TS were optimal parameters, and corresponding CST reached 43.7 s. Soluble organics in extracellular polymeric substances (EPS) were determined by three-dimensional excitation-emission matrix fluorescence spectroscopy, which was used to explain the mechanism of sludge dewaterability. The fluorescence intensities of protein-like and humic-like substances in EPS had a negative relationship with the CST. Scanning electron microscopy images indicated that calcium chloride neutralized the surface charge of particles, making the soluble protein-like substances agglomerate and form bigger flocs, consequently enhancing sludge dewaterability.

【 授权许可】

CC BY-NC-ND