title: Sewage sludge nutrient solubilization using a single-stage microwave treatment.
abstract: The effects of an advanced oxidation process combining microwave, hydrogen peroxide and acid hydrolysis in a single stage (MW/H2O2/H+ -AOP) on the process efficiency of sewage sludge treatment and nutrient recovery were investigated. At lower temperature regimes (60-80 degrees C), the soluble phosphate was substantially higher in a two-stage process than in a single stage MW/H2O2/H+ -AOP process. However, higher soluble phosphate concentration was obtained for single-stage treatment at the higher operating temperature regimes (100-120 degrees C). With the addition of an inorganic acid, a very high yield of soluble phosphate was obtained in the solution at 120 degrees C. In tests with acid addition, soluble ammonia increased as temperature increased. For single stage MW/H2O2/H+ -AOP, maximum soluble ammonia was obtained at 120 degrees C. Significant concentrations of soluble COD were also obtained in this treatment. A threshold temperature of 80 degrees C was observed, at which all of the COD could be solubilized. However, at higher temperatures (100-120 degrees C), further oxidation processes occurred to form carbon dioxide, resulting in decreased amounts of soluble COD in the solution.
authors.affiliation: Department of Civil Engineering, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Winnie I
authors.initials: WI
authors.lastname: Chan
authors.forename: Wayne T
authors.initials: WT
authors.lastname: Wong
authors.forename: Ping H
authors.initials: PH
authors.lastname: Liao
authors.forename: Kwang V
authors.initials: KV
authors.lastname: Lo
mesh_terms: D000641:Ammonia / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008872:Microwaves; D010710:Phosphates / Q000032:analysis* / Q000737:chemistry / Q000528:radiation effects; D012722:Sewage / Q000737:chemistry*; D012995:Solubility; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D010710:Phosphates; D012722:Sewage; D000641:Ammonia; D006861:Hydrogen Peroxide