title: A new algorithm for design, operation and cost assessment of struvite (MgNH4PO4) precipitation processes.
abstract: Deliberate struvite (MgNH4PO4) precipitation from wastewater streams has been the topic of extensive research in the last two decades and is expected to gather worldwide momentum in the near future as a P-reuse technique. A wide range of operational alternatives has been reported for struvite precipitation, including the application of various Mg(II) sources, two pH elevation techniques and several Mg:P ratios and pH values. The choice of each operational parameter within the struvite precipitation process affects process efficiency, the overall cost and also the choice of other operational parameters. Thus, a comprehensive simulation program that takes all these parameters into account is essential for process design. This paper introduces a systematic decision-supporting tool which accepts a wide range of possible operational parameters, including unconventional Mg(II) sources (i.e. seawater and seawater nanofiltration brines). The study is supplied with a free-of-charge computerized tool (http://tx.technion.ac.il/~agrengn/agr/Struvite_Program.zip) which links two computer platforms (Python and PHREEQC) for executing thermodynamic calculations according to predefined kinetic considerations. The model can be (inter alia) used for optimizing the struvite-fluidized bed reactor process operation with respect to P removal efficiency, struvite purity and economic feasibility of the chosen alternative. The paper describes the algorithm and its underlying assumptions, and shows results (i.e. effluent water quality, cost breakdown and P removal efficiency) of several case studies consisting of typical wastewaters treated at various operational conditions.
authors.affiliation: a Faculty of Civil and Environmental Engineering , Technion - Israel Institute of Technology , Technion City , Haifa 32000 , Israel.
authors.forename: Liat
authors.initials: L
authors.lastname: Birnhack
authors.forename: Oded
authors.initials: O
authors.lastname: Nir
authors.forename: Marina
authors.initials: M
authors.lastname: Telzhenski
authors.forename: Ori
authors.initials: O
authors.lastname: Lahav
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005590:Fractional Precipitation / Q000191:economics* / Q000295:instrumentation*; D007557:Israel; D017616:Magnesium Compounds / Q000737:chemistry / Q000191:economics* / Q000302:isolation & purification; D008956:Models, Chemical; D010710:Phosphates / Q000737:chemistry / Q000191:economics* / Q000302:isolation & purification; D000069877:Struvite; D014865:Waste Disposal, Fluid / Q000191:economics* / Q000295:instrumentation; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000191:economics / Q000302:isolation & purification; D018508:Water Purification / Q000191:economics* / Q000295:instrumentation
chemical_list: D017616:Magnesium Compounds; D010710:Phosphates; D014874:Water Pollutants, Chemical; D000069877:Struvite
keywords: cost assessment; operational conditions; phosphorous removal; simulation algorithm; struvite recovery