title: A kinetic study of struvite precipitation recycling technology with NaOH/Mg(OH)2 addition.
abstract: Struvite precipitation recycling technology is received wide attention in removal ammonium and phosphate out of wastewater. While past study focused on process efficiency, and less on kinetics. The kinetic study is essential for the design and optimization in the application of struvite precipitation recycling technology. The kinetics of struvite with NaOH/Mg(OH)2 addition were studied by thermogravimetry analysis with three rates (5, 10, 20 °C/min), using Friedman method and Ozawa-Flynn-Wall method, respectively. Degradation process of struvite with NaOH/Mg(OH)2 addition was three steps. The stripping of ammonia from struvite was mainly occurred at the first step. In the first step, the activation energy was about 70 kJ/mol, which has gradually declined as the reaction progress. By model fitting studies, the proper mechanism function for struvite decomposition process with NaOH/Mg(OH)2 addition was revealed. The mechanism function was f(α)=α(α)-(1-α)(n), a Prout-Tompkins nth order (Bna) model.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
authors.forename: Rongtai
authors.initials: R
authors.lastname: Yu
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Ren
authors.forename: Yanru
authors.initials: Y
authors.lastname: Wang
authors.forename: Lili
authors.initials: L
authors.lastname: Ding
authors.forename: Jingji
authors.initials: J
authors.lastname: Geng
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D007700:Kinetics; D017616:Magnesium Compounds / Q000737:chemistry*; D008276:Magnesium Hydroxide / Q000737:chemistry*; D008956:Models, Chemical; D010710:Phosphates / Q000737:chemistry*; D059027:Recycling; D012972:Sodium Hydroxide / Q000737:chemistry*; D000069877:Struvite; D013818:Thermogravimetry
chemical_list: D017616:Magnesium Compounds; D010710:Phosphates; D012972:Sodium Hydroxide; D000069877:Struvite; D008276:Magnesium Hydroxide
keywords: Activation energy; Kinetics; Model; Pre-exponential; Struvite precipitation recycling