title: Phosphate recovery through struvite-family crystals precipitated in the presence of citric acid: mineralogical phase and morphology evaluation.
abstract: Precipitation strategy of struvite-family crystals is presented in this paper to recover phosphate and potassium from a synthetic wastewater in the presence of citric acid at elevated temperature. The crystal-forming solutions were prepared from crystals of MgCl2and NH4H2PO4with a molar ratio of 1:1:1 for Mg+2, [Formula: see text], and [Formula: see text], and the citric acid (C6H8O7) was prepared (1.00 and 20.00 ppm) from citric acid crystals. The Rietveld analysis of X-ray powder diffraction pattern confirmed a mixed product of struvite, struvite-(K), and newberyite crystallized at 30°C in the absence of citric acid. In the presence of citric acid at 30° and 40°C, an abundance of struvite and struvite-(K) were observed. A minute impurity of sylvite and potassium peroxide was unexpectedly found in certain precipitates. The crystal solids have irregular flake-shaped morphology, as shown by scanning electron microscopy micrograph. All parameters (citric acid, temperature, pH, Mg/P, and N/P) were deliberately arranged to control struvite-family crystals precipitation.
authors.affiliation: a Department of Chemical Engineering , Universitas Pembangunan Nasional 'Veteran' Jawa Timur , Surabaya , Indonesia.|b Center for Waste Management, Department of Mechanical Engineering , Diponegoro University , Semarang , Indonesia.
authors.forename: D S
authors.initials: DS
authors.lastname: Perwitasari
authors.affiliation: a Department of Chemical Engineering , Universitas Pembangunan Nasional 'Veteran' Jawa Timur , Surabaya , Indonesia.|b Center for Waste Management, Department of Mechanical Engineering , Diponegoro University , Semarang , Indonesia.
authors.forename: L
authors.initials: L
authors.lastname: Edahwati
authors.affiliation: a Department of Chemical Engineering , Universitas Pembangunan Nasional 'Veteran' Jawa Timur , Surabaya , Indonesia.|b Center for Waste Management, Department of Mechanical Engineering , Diponegoro University , Semarang , Indonesia.
authors.forename: S
authors.initials: S
authors.lastname: Sutiyono
authors.affiliation: b Center for Waste Management, Department of Mechanical Engineering , Diponegoro University , Semarang , Indonesia.|c Department of Chemical Engineering , UNTAG University , Semarang , Indonesia.
authors.forename: S
authors.initials: S
authors.lastname: Muryanto
authors.affiliation: b Center for Waste Management, Department of Mechanical Engineering , Diponegoro University , Semarang , Indonesia.
authors.forename: J
authors.initials: J
authors.lastname: Jamari
authors.affiliation: b Center for Waste Management, Department of Mechanical Engineering , Diponegoro University , Semarang , Indonesia.
authors.forename: A P
authors.initials: AP
authors.lastname: Bayuseno
mesh_terms: D011232:Chemical Precipitation; D019343:Citric Acid / Q000737:chemistry*; D017616:Magnesium Compounds / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry*; D000069877:Struvite / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry
chemical_list: D019343:Citric Acid; D017616:Magnesium Compounds; D010710:Phosphates; D011188:Potassium; D000069877:Struvite; D062065:Wastewater; C030781:magnesium phosphate
keywords: Precipitation; XRPD Rietveld analysis; citric acid; elevated temperature; struvite-family crystals