Effect of humic substances on phosphorus removal by struvite precipitation.
Chemosphere
; 141: 94-9, 2015 Dec.
Article
em En
| MEDLINE
| ID: mdl-26151483
ABSTRACT
Humic substances (HS) are a major fraction of dissolved organic matters in wastewater. The effect of HS on phosphorus removal by struvite precipitation was investigated using synthetic wastewater under different initial pH values, Mg/P molar ratios and HS concentrations. The composition, morphology and thermal properties of harvested precipitates were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and thermo-gravimetric analysis (TGA), respectively. It showed that inhibition effect of HS reached its maximum value of 48.9% at pH 8.0, and decreased to below 10% at pH>9.0. The increase of Mg/P ratio enhanced phosphorus removal efficiency, and thus reduced the influence of HS on struvite precipitation. At pH 9.0, the inhibitory effect of initial HS concentration matched the modified Monod model with half maximum inhibition concentration of 356mgL(-1), and 29% HS was removed in conjunction with struvite crystallisation. XRD analysis revealed that the crystal form of struvite precipitates was changed in the presence of HS. The morphology of harvested struvite was transformed from prismatic to pyramid owing to the coprecipitation of HS on crystal surface. TGA results revealed that the presence of HS could compromise struvite purity.
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Base de dados:
MEDLINE
Assunto principal:
Fosfatos
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Fósforo
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Compostos de Magnésio
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Purificação da Água
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Águas Residuárias
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Substâncias Húmicas
Idioma:
En
Revista:
Chemosphere
Ano de publicação:
2015
Tipo de documento:
Article