title: Enhancement of struvite pellets crystallization in a full-scale plant using an industrial grade magnesium product.
abstract: A full-scale struvite crystallization system was operated for the treatment of the centrate obtained from the sludge anaerobic digester in a municipal wastewater treatment plant. Additionally, the feasibility of an industrial grade Mg(OH)2as a cheap magnesium and alkali source was also investigated. The struvite crystallization plant was operated for two different periods: period I, in which an influent with low phosphate concentration (34.0 mg P·L-1) was fed to the crystallization plant; and period II, in which an influent with higher phosphate concentration (68.0 mg P·L-1) was used. A high efficiency of phosphorus recovery by struvite crystallization was obtained, even when the effluent treated had a high level of alkalinity. Phosphorus recovery percentage was around 77%, with a phosphate concentration in the effluent between 10.0 and 30.0 mg P·L-1. The experiments gained struvite pellets of 0.5-5.0 mm size. Moreover, the consumption of Mg(OH)2was estimated at 1.5 mol Mg added·mol P recovered-1. Thus, industrial grade Mg(OH)2can be an economical alternative as magnesium and alkali sources for struvite crystallization at industrial scale.
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, Santiago de Compostela 15782, Spain E-mail: dafne.crutchik@gmail.com; Faculty of Engineering and Sciences, Universidad Adolfo Ibáñez, Diagonal Las Torres 2640, Santiago, Chile.
authors.forename: D
authors.initials: D
authors.lastname: Crutchik
authors.affiliation: FCC Aqualia, Guillarei WWTP, Camino de la Veiga s/n, Tui E-36720, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Morales
authors.affiliation: FCC Aqualia, Guillarei WWTP, Camino de la Veiga s/n, Tui E-36720, Spain.
authors.forename: J R
authors.initials: JR
authors.lastname: Vázquez-Padín
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, Santiago de Compostela 15782, Spain E-mail: dafne.crutchik@gmail.com.
authors.forename: J M
authors.initials: JM
authors.lastname: Garrido
mesh_terms: D003460:Crystallization; D005240:Feasibility Studies; D008276:Magnesium Hydroxide / Q000737:chemistry*; D010710:Phosphates / Q000032:analysis* / Q000737:chemistry; D012722:Sewage / Q000737:chemistry; D000069877:Struvite / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D014873:Water Pollutants / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D008276:Magnesium Hydroxide; D010710:Phosphates; D012722:Sewage; D000069877:Struvite; D062065:Wastewater; D014873:Water Pollutants