title: Ultrasonic application to boost hydroxyl radical formation during Fenton oxidation and release organic matter from sludge.
abstract: We examined the effects of ultrasound and Fenton reagent on ultrasonic coupling Fenton oxidation (U+F) pre-treatment processes for the disintegration of wastewater treatment plant sludge. The results demonstrated that U+F treatment could significantly increase soluble chemical oxygen demand (SCOD), total organic carbon (TOC), and extracellular polymeric substances (EPS) concentrations in sludge supernatant. This method was more effective than ultrasonic (U) or Fenton oxidation (F) treatment alone. U+F treatment increased the release of SCOD by 2.1- and 1.4-fold compared with U and F alone, respectively. U+F treatment increased the release of EPS by 1.2-fold compared with U alone. After U+F treatment, sludge showed a considerably finer particle size and looser microstructure based on fluorescence microscopy, and the concentration of hydroxyl radicals (OH•) increased from 0.26 mM by F treatment to 0.43 mM by U+F treatment based on fluorescence spectrophotometer. This demonstrated that U+F treatment improves the release of organic matter from sludge.
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Changxiu
authors.initials: C
authors.lastname: Gong
authors.affiliation: 1] School of Environment, Tsinghua University, Beijing 100084, China [2] Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China, China [3] Collaborative Innovation Center for Regional Environmental Quality, Tsinghua University, Beijing, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Jiang
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: De'an
authors.initials: D
authors.lastname: Li
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Sicong
authors.initials: S
authors.lastname: Tian
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D012722:Sewage; D000069453:Ultrasonic Waves
chemical_list: C045076:Fenton's reagent; D012722:Sewage; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron