. "Paris, France" . "S, Z(MSM6046137308)" . "Effects of organic matter on the crystallization of struvite crystals in biologically treated swine wastewater"@en . . . "22320" . "Influence de la matiere organique sur la pr\u00E9cipitation de struvite dans du lisier de porcs trait\u00E9 biologiquement" . "79648" . "RIV/60461373:22320/13:43895150!RIV14-MSM-22320___" . . . . "Effects of organic matter on the crystallization of struvite crystals in biologically treated swine wastewater"@en . "Beline, Fabrice" . "Capdevielle, Aur\u00E9lie" . . . "Daumer, Marie-Line" . "R\u00E9cents Progres en G\u00E9nie des Proc\u00E9d\u00E9s, Vol. 3" . "SFGP" . "5"^^ . . "RIV/60461373:22320/13:43895150" . "L?influence de la MO sur la pr\u00E9cipitation de struvite a \u00E9t\u00E9 observ\u00E9e dans le domaine du traitement des effluents porcins mais n?a pas, ? notre connaissance, \u00E9t\u00E9 quantifi\u00E9e. L?influence de la MO sur la pr\u00E9cipitation du phosphore a \u00E9t\u00E9 \u00E9tudi\u00E9e sur trois fractions de lisier de porcs trait\u00E9 biologiquement et acidifi\u00E9es ? pH 4,5: une fraction totale, une fraction centrifug\u00E9e et une fraction filtr\u00E9e ? 0,45 ?m. Les r\u00E9sultats des essais en milieu r\u00E9el ont \u00E9t\u00E9 compar\u00E9s ? ceux obtenus en milieu synth\u00E9tique. La pr\u00E9cipitation a \u00E9t\u00E9 conduite par ajout de MgO. Le pH maximal atteint est rest\u00E9 inf\u00E9rieur ? 7,5 d?o? la formation d?esp?ces phosphat\u00E9es autres que la struvite (MgNH4PO4?6H2O) et le phosphate de calcium amorphe (ACP). Les concentrations ioniques (Mg2+, Ca2+, N-NH4+, P-PO43-), le pH, la taille et la forme des cristaux ont \u00E9t\u00E9 suivis pendant 24 heures. Les essais r\u00E9alis\u00E9s ont mis en \u00E9vidence trois types d?influence de la MO : des cin\u00E9tiques de pr\u00E9cipitation et de dissolution plus faibles qu?en milieu synth\u00E9tique, des faci?s de cristaux diff\u00E9rents et des tailles de cristaux plus importantes. Suivant la nature des fractions de la MO (dissoute, collo?dale ou particulaire), plusieurs hypoth?ses sont propos\u00E9es. Les groupes fonctionnels de la MO dissoute se fixent ? la fois sur les germes de brushite (CaHPO4?2H2O) et sur les particules de Mg(OH)2 emp?chant leur croissance ou leur dissociation. La viscosit\u00E9 induite par la pr\u00E9sence de particules collo?dales ralentit les cin\u00E9tiques de pr\u00E9cipitation/dissolution en diminuant le noyau d?agr\u00E9gation des particules de struvite/brushite. Enfin, la MO particulaire semble opposer en plus une g?ne st\u00E9rique ? la nucl\u00E9ation de struvite. Bien que moins de struvite ait \u00E9t\u00E9 form\u00E9e en pr\u00E9sence de MO particulaire, les cristaux sont beaucoup plus gros et leur forme offre une meilleure r\u00E9sistance ? la brisure." . . . "Santellani, Anne-C\u00E9cile" . "1775-335X" . . "2-910239-77-2" . "1"^^ . "Influence de la matiere organique sur la pr\u00E9cipitation de struvite dans du lisier de porcs trait\u00E9 biologiquement" . . . . "2013-05-16+02:00"^^ . "The precipitation of struvite is not only influenced by the process parameters but also by the organic matter (OM). In urology, the OM inhibits or promotes the struvite crystallization function of the length and the charge of the carbon chain. Whereas the influence of OM was observed on the struvite precipitation in swine wastewaters, it has never been, to our knowledge, quantified in processes applied on farm. The influence of OM on the precipitation of phosphorus was studied on three fractions of swine wastewaters acidified to pH 4.5 and biologically treated: a total fraction, a centrifuged fraction and a fraction filtered at 0.45 ?m. The results of these precipitation runs were compared to those obtained in synthetic medium. The precipitation started with the addition of MgO. The maximum pH reached remained below 7.5 which enable the formation of phosphate species other than struvite (MgNH4PO4?6H2O) or amorphous calcium phosphate (ACP). Ion concentrations (Mg2+, Ca2+, N-NH4+, P-PO43-), pH, size and shape of the crystals were monitoring during 24 hours. The results revealed three kinds of influence of the MO: the kinetics of dissolution and precipitation were lower than in synthetic medium, the crystals habits were different and the crystals sizes larger. Depending on the nature of the OM fractions (dissolved, colloidal and particulate), several hypotheses are proposed. The functional groups of the dissolved OM are fixed on both the seeds of brushite (CaHPO4?2H2O) and the particles of Mg(OH)2 inhibiting their growth or their cleavage. The viscosity induced by the presence of colloidal particles slows the kinetics of precipitation/dissolution by reducing the aggregation kernel of the particles of struvite/brushite. Finally, particulate OM seems to oppose steric hindrance to the nucleation of struvite. Although less struvite was formed in the presence of particulate OM, the crystals were larger and their shape had better resistance to breakage."@en . "[459597851C8E]" . . . "Toulouse, Albi" . "Swine wastewaters; Organic matter; Crystallization; Phosphorus; Struvite"@en . . . "S\u00FDkorov\u00E1, Eva" . "10"^^ . .