title: Three-dimensional fluorescence excitation-emission matrix (EEM) spectroscopy with regional integration analysis for assessing waste sludge hydrolysis treated with multi-enzyme and thermophilic bacteria.
abstract: The hydrolysis effect of waste sludge after multi-enzyme and thermophilic bacteria pretreatments is investigated using excitation-emission matrix (EEM) with fluorescence regional integration (FRI) in this study. The compositional characteristics of extracellular polymeric substances (EPS) and dissolved organic matters (DOM) were analyzed to evaluate the sludge disintegration. The EPS and cell wall in sludge were disrupted after hydrolysis which led to carbohydrate, protein and soluble chemical oxygen demand (SCOD) of DOM increasing in sludge supernatant. The bio-degradability level in the extracted fractions of EPS and DOM depending on the fluorescence zones was found after hydrolysis. The highest proportion of percent fluorescence response (Pi,n) in EPS and DOM was soluble microbial by-product and humic acid-like organics. A significant increase of humic acid-like organics in DOM after thermophilic bacteria hydrolysis was obtained. The assessment of hydrolysis using EEM coupled with FRI provided a new insight toward the bio-utilization process of waste sludge.
authors.affiliation: Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China. Electronic address: geletu@ouc.edu.cn.
authors.forename: Liang
authors.initials: L
authors.lastname: Guo
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Mingmin
authors.initials: M
authors.lastname: Lu
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: Jiawen
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zong
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Zonglian
authors.initials: Z
authors.lastname: She
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D002498:Centrifugation; D004798:Enzymes / Q000378:metabolism*; D006868:Hydrolysis; D008872:Microwaves; D012722:Sewage / Q000382:microbiology*; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D004798:Enzymes; D012722:Sewage
keywords: EEM; FRI; Multi-enzyme; Sludge hydrolysis; Thermophilic bacteria