title: Enhanced dewatering of excess activated sludge through decomposing its extracellular polymeric substances by a Fe@Fe2O3-based composite conditioner.
abstract: Efficient sludge dewatering methods are highly desired by municipal wastewater treatment plants. In this study, Fe@Fe2O3 nanomaterial, combined with polydiallyldimethylammonium chloride (PDMDAAC) and H2SO4, was used for sludge dewatering. This composite conditioner exhibited an excellent dewatering capability. By using uniform design, the optimized dosages of Fe@Fe2O3, H2SO4 and PDMDAAC were determined to be 40, 136 and 4.8mg/gDS (dry solids), respectively. The moisture content of sludge cake decreased from 78.1% to 64.8%, and the capillary suction time from 56 to 21s. The sludge extracellular polymeric substances (EPS) were decomposed, resulting in greater conversion of the bound water into free water and the release of free water. The electron spin resonance results show that the molecular oxygen activation process induced by Fe@Fe2O3 produced hydroxyl radicals, which were mainly responsible for the EPS decomposition. In this way, an efficient composite conditioner for enhancing sludge dewatering was developed.
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China.
authors.forename: Dong-Qin
authors.initials: DQ
authors.lastname: He
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China.
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Luo
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China.
authors.forename: Bao-Cheng
authors.initials: BC
authors.lastname: Huang
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Qian
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China. Electronic address: hqyu@ustc.edu.cn.
authors.forename: Han-Qing
authors.initials: HQ
authors.lastname: Yu
mesh_terms: D002152:Calorimetry, Differential Scanning; D005290:Ferric Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical; D007501:Iron / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012722:Sewage; D013464:Sulfuric Acids / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; D011095:Polyethylenes; D011108:Polymers; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D013464:Sulfuric Acids; D014867:Water; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D017665:Hydroxyl Radical; D007501:Iron; C033158:sulfuric acid; D010100:Oxygen
keywords: Composite conditioner; Dewatering; Excess activated sludge; Extracellular polymeric substances (EPS); Fe@Fe(2)O(3); Uniform design