title: Improving dewaterability of waste activated sludge by combined conditioning with zero-valent iron and hydrogen peroxide.
abstract: Improvement of sludge dewaterability is crucial for reducing the costs of sludge disposal in wastewater treatment plants. This study presents a novel method based on combined conditioning with zero-valent iron (ZVI) and hydrogen peroxide (HP) at pH 2.0 to improve dewaterability of a full-scale waste activated sludge (WAS). The combination of ZVI (0-750mg/L) and HP (0-750mg/L) at pH 2.0 substantially improved the WAS dewaterability due to Fenton-like reactions. The highest improvement in WAS dewaterability was attained at 500mg ZVI/L and 250mg HP/L, when the capillary suction time of the WAS was reduced by approximately 50%. Particle size distribution indicated that the sludge flocs were decomposed after conditioning. Economic analysis showed that combined conditioning with ZVI and HP was a more economically favorable method for improving WAS dewaterability than the classical Fenton reaction based method initiated by ferrous salts and HP.
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Qilin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Guangming
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Xiwang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia. Electronic address: zhiguo@awmc.uq.edu.au.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Yuan
mesh_terms: D061249:Batch Cell Culture Techniques; D005427:Flocculation; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014866:Waste Products / Q000032:analysis*; D014867:Water / Q000737:chemistry*; D018508:Water Purification / Q000191:economics / Q000379:methods*
chemical_list: C045076:Fenton's reagent; D012722:Sewage; D014866:Waste Products; D014867:Water; D006861:Hydrogen Peroxide; D007501:Iron
keywords: Dewaterability; Fenton-like reaction; Hydrogen peroxide; Waste activated sludge; Zero-valent iron