title: Evaluating filterability of different types of sludge by statistical analysis: The role of key organic compounds in extracellular polymeric substances.
abstract: An investigation was conducted for 20 different types of sludge in order to identify the key organic compounds in extracellular polymeric substances (EPS) that are important in assessing variations of sludge filterability. The different types of sludge varied in initial total solids (TS) content, organic composition and pre-treatment methods. For instance, some of the sludges were pre-treated by acid, ultrasonic, thermal, alkaline, or advanced oxidation technique. The Pearson's correlation results showed significant correlations between sludge filterability and zeta potential, pH, dissolved organic carbon, protein and polysaccharide in soluble EPS (SB EPS), loosely bound EPS (LB EPS) and tightly bound EPS (TB EPS). The principal component analysis (PCA) method was used to further explore correlations between variables and similarities among EPS fractions of different types of sludge. Two principal components were extracted: principal component 1 accounted for 59.24% of total EPS variations, while principal component 2 accounted for 25.46% of total EPS variations. Dissolved organic carbon, protein and polysaccharide in LB EPS showed higher eigenvector projection values than the corresponding compounds in SB EPS and TB EPS in principal component 1. Further characterization of fractionized key organic compounds in LB EPS was conducted with size-exclusion chromatography-organic carbon detection-organic nitrogen detection (LC-OCD-OND). A numerical multiple linear regression model was established to describe relationship between organic compounds in LB EPS and sludge filterability.
authors.affiliation: Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
authors.forename: Keke
authors.initials: K
authors.lastname: Xiao
authors.affiliation: Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
authors.forename: Xie
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore. Electronic address: ZhouYan@ntu.edu.sg.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D002850:Chromatography, Gel / Q000379:methods; D005374:Filtration; D016014:Linear Models; D011108:Polymers / Q000032:analysis* / Q000737:chemistry; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D012995:Solubility; D013010:Sonication; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods* / Q000706:statistics & numerical data
chemical_list: D011108:Polymers; D011134:Polysaccharides; D011506:Proteins; D012722:Sewage; D014874:Water Pollutants, Chemical
keywords: Fractionized organic compounds; Loosely bound extracellular polymeric substances; Pearson's correlation analysis; Principal component analysis; Sludge filterability