title: Three-dimensional fluorescence excitation-emission matrix (EEM) spectroscopy with regional integration analysis for assessing waste sludge hydrolysis at different pretreated temperatures.
abstract: Heat pretreatment process can promote sludge hydrolysis and enhance the degradability of waste sludge. The effect of heat pretreatment at different temperatures on the changes of soluble chemical oxygen demand (SCOD), carbohydrates, and proteins and the structural and functional properties of organics in extracellular polymeric substances (EPS) and dissolved organic matters (DOM) were systematically investigated. Heat pretreatment was conducted at 65, 80, 100, and 121 °C for 30 min. The SCOD in DOM increased with pretreated temperatures. Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy was utilized to evaluate the biodegradable and non-biodegradable components in EPS and DOM. Moreover, the humification index (HIX) and the fluorescence index (FI) were used to evaluate the humification and DOM source. At 80 °C, the percent fluorescence response (Pi,n) of easily biodegradable soluble microbial by-product substance was higher than others; meanwhile, little non-biodegradable humic acid-like substance was accumulated. In order to enhance sludge biodegradability, 80 °C was chosen as the optimal temperature for heat pretreatment.
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China. geletu@ouc.edu.cn.|Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China. geletu@ouc.edu.cn.|Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Qingdao, 266100, China. geletu@ouc.edu.cn.
authors.forename: Liang
authors.identifier: http://orcid.org/0000-0002-2481-7256
authors.initials: L
authors.lastname: Guo
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Li
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
authors.forename: Yangguo
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
authors.forename: Mengchun
authors.initials: M
authors.lastname: Gao
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China. szlszl@ouc.edu.cn.
authors.forename: Zonglian
authors.initials: Z
authors.lastname: She
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
authors.forename: Chunji
authors.initials: C
authors.lastname: Jin
mesh_terms: D057919:Biological Oxygen Demand Analysis; D005453:Fluorescence; D006358:Hot Temperature; D006812:Humic Substances / Q000032:analysis; D006868:Hydrolysis; D012722:Sewage / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods*
chemical_list: D006812:Humic Substances; D012722:Sewage
keywords: DOM; EEM; EPS; Heat pretreatment; Hydrolysis; Waste sludge