title: Combination of struvite pyrolysate recycling with mixed-base technology for removing ammonium from fertilizer wastewater.
abstract: Removal of ammonium from wastewater via struvite (MAP) pyrolysate recycling combined with a mixed-base NaOH/Mg(OH)(2) technology was investigated, and the phosphate and magnesium concentration in the supernatant were measured. The optimal parameters for acidolysis were a pH of 1; temperature of 120°C and time of 2h. The presence of derivatives of amorphous magnesium hydrogen phosphate (MgHPO(4)), namely magnesium phosphate (Mg(3)(PO(4))(2)) and magnesium pyrophosphate (Mg(2)P(2)O(7)) were verified by experiment. The ammonium removal ratio in this combined mixed-base technology was 96.8% in the first cycle, 80.6% in the second, and 81.0% after acidolysis. The phosphate and magnesium ions concentration in the supernatant were about 1mg/L and 40 mg/L, respectively. The grain size of MAP was 1.52 nm without seeding and 1.79 nm with seeding, and the growth rate of MAP was 17.6%.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, Jiangsu, PR China.
authors.forename: Rongtai
authors.initials: R
authors.lastname: Yu
authors.forename: Jinju
authors.initials: J
authors.lastname: Geng
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Ren
authors.forename: Yanru
authors.initials: Y
authors.lastname: Wang
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
mesh_terms: D005308:Fertilizers; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D017616:Magnesium Compounds / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification*; D000069877:Struvite; D062065:Wastewater / Q000737:chemistry*
chemical_list: D005308:Fertilizers; D017616:Magnesium Compounds; D010710:Phosphates; D000644:Quaternary Ammonium Compounds; D000069877:Struvite; D062065:Wastewater