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Laboratory and pilot-scale phosphate and ammonium removal by controlled struvite precipitation following coagulation and flocculation of swine wastewater

NRS-Eau, Terre et Environnement, Université du Québec, 490, rue de la Couronne, Québec, QC, G1K 9A9, Canada.
Environmental Technology (Impact Factor: 1.2). 06/2005; 26(5):525-36. DOI: 10.1080/09593332608618533
Source: PubMed

ABSTRACT To reduce the suspended solids load to a trickling filter installation, raw swine effluent was pre-treated with ferric chloride and a cationically charged polyacrylamide coagulant resulting in unexpected struvite accumulation downstream of this post-separation process. Using this pre-treated swine manure, struvite precipitation studies were carried out as a function of pH at laboratory and pilot batch and continuously operated scales. An optimal reaction time of 30 min was established for struvite precipitation in the pre-treated swine wastewater at pH 8.5, minimizing the co-precipitation of interfering minerals. Ferric chloride addition resulted in magnesium solubilization, such that no external additional source of magnesium was required for struvite formation. Aeration alone did not result in significant pH increases, so base addition was required for pH adjustment. X-ray diffraction revealed that the only crystalline phase produced was struvite. Removal of phosphate and ammonium attained 98% and 17% respectively in laboratory scale experiments. At the pilot-scale, removal attained 99% and 15% of phosphate and ammonium in both batch and continuously HRT = 1h) operated reactors.

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    • "chemical engineering research and design x x x ( 2 0 1 2 ) xxx–xxx address phosphorus removal by water professionals (Gonzalez and De Sa, 2007). MAP crystallization has been applied for several purposes, such as to prevent scaling problems (Doyle and Parsons, 2004) and to remove phosphate (Battistoni et al., 1997) or nitrogen (Laridi et al., 2005). Recent publications show an increasing interest in struvite precipitation as a technology for phosphorus recovery taking into account the economic impact of increasing energy costs and limited natural phosphorus resources (Carballa et al., 2008; Forrest et al., 2008). "
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    Chemical Engineering Research and Design 05/2013; 91(5):810–818. DOI:10.1016/j.cherd.2012.09.017 · 2.28 Impact Factor
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    • "Nutrient removal by struvite (MgNH 4 PO 4 · 6H 2 O) or magnesium ammonium phosphate (MAP) precipitation is an interesting alternative approach to address phosphorus removal (von Munch and Barr, 2001; Gonzalez and De Sa, 2007). MAPc rystallisation can be applied for several purposes, such as to prevent scalingp roblems (Doyle and Parsons, 2004) and to remove phosphate (Battistoni et al.,1 997) or nitrogen(Altinbas et al.,2002; Laridi et al.,2005). Recent publications show an increasing interest in struvite precipitation as at echnology for phosphorus recovery taking into account the economic impact of increasing energy costsand limited natural phosphorus resources (Durrant et al.,1 999; Shu et al.,2 006; Carballa et al.,2 008; Forrest et al.,2 008). "
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    ABSTRACT: Pilot-scale struvite crystallization tests using anaerobic effluent from potato processing industries were performed at three different plants. Two plants (P1 & P2) showed high phosphate removal efficiencies, 89+/-3% and 75+/-8%, resulting in final effluent levels of 12+/-3 mg PO(4)(3-)-PL(-1) and 11+/-3mg PO(4)(3-)-PL(-1), respectively. In contrast, poor phosphate removal (19+/-8%) was obtained at the third location (P3). Further investigations at P3 showed the negative effect of high Ca(2+)/PO(4)(3-)-P molar ratio (ca. 1.25+/-0.11) on struvite formation. A full-scale struvite plant treating anaerobic effluent from a dairy industry showed the same Ca(2+) interference. A shift in the influent Ca(2+)/PO(4)(3-)-P molar ratio from 2.69 to 1.36 resulted in average total phosphorus removal of 78+/-7%, corresponding with effluent levels of 14+/-4 mg P(total)L(-1) (9+/-3 mg PO(4)(3-)-PL(-1)). Under these conditions high quality spherical struvite crystals of 2-6mm were produced.
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    • "Ammonia is completely soluble, and one would not normally expect any removal by separation beyond that of partition. Some ammonia can be removed as struvite in what is also known as the MAP process (magnesium–ammonia–phosphate ) (Munch and Barr, 2001; Laridi et al., 2005), but the quantity precipitated is modest compared to the large amounts of magnesium and phosphorous required. An alternative strategy is to adsorb the ammonia using zeolites, and then to separate as a nitrogen rich sludge. "
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