نتایج جستجو برای: mineral phosphate

تعداد نتایج: 168424  

2006
D. Vantelon A. Hofmann K. Hanselmann A. M. Flank

In a high mountain lake and catchment area, a natural process of phosphorus enrichment is observed, induced by the iron-cycle. Investigations focus on the speciation of P and Fe in iron and manganese rich oxidic mineral crusts formed at the surface of rock pebbles. Iron and phosphorus are spatially associated although they are not forming iron phosphate minerals. While Fe and P K edge XAS spect...

2011
P. ÁLVAREZ-LLORET

Bone is a composite biomaterial mainly composed of packed collagen fibres and nano-sized hydroxylapatite (HA) crystals. Quantitative measurements of bone mine­ ral composition can provide insights into the bone mine­ ral formation in health and disease . Bone mineral characteristics such as crystal lini ty, carbonate and phosphate mineral content may vary as a function of age, sex, diet, bone l...

2011
Karen E Wright Thomas Hartmann Yoshiko Fujita

BACKGROUND Induced precipitation of phosphate minerals to scavenge trace elements from groundwater is a potential remediation approach for contaminated aquifers. The success of engineered precipitation schemes depends on the particular phases generated, their rates of formation, and their long term stability. The purpose of this study was to examine the precipitation of calcium phosphate minera...

Journal: :Applied and environmental microbiology 1995
S Babu-Khan T C Yeo W L Martin M R Duron R D Rogers A H Goldstein

We have recently shown that the ability of some gram-negative bacteria to dissolve poorly soluble calcium phosphates (Mps+ phenotype) is the result of periplasmic oxidation of glucose to gluconic acid via the quinoprotein glucose dehydrogenase (GDH), a component of the direct oxidation pathway. Escherichia coli K-12 derivatives synthesize apo-GDH but not the cofactor pyrroloquinoline-quinone (P...

Journal: :Environment international 2006
Sona Saxena S F D'Souza

The low-grade rock phosphate of Jhabua, Madhya Pradesh (India), was investigated for its possible application in the removal of lead, copper, zinc and cobalt ions from aqueous solutions. Effects of contact time, amount of adsorbent and initial concentration of metal ions were studied. Adsorption of heavy metal ions was found to follow the order: Pb2+ > Cu2+ > Zn2+ > Co2+. The probable mechanism...

2001
H. M. Dion J. B. Harsh H. H. Hill

Inorganic phosphate may influence the adsorption of glyphosate to soil surface sites. It has been postulated that glyphosate sorption is dominated by the phosphoric acid moiety, therefore, inorganic phosphate could compete with glyphosate for surface sorption sites. We examine sorption of glyphosate in low organic carbon systems where clay minerals dominate the available adsorption sites using ...

Journal: :Environmental science & technology 2009
Drew Gorman-Lewis Tatiana Shvareva Karrie-Ann Kubatko Peter C Burns Dawn M Wellman Bruce Mcnamara Jennifer E S Szymanowski Alexandra Navrotsky Jeremy B Fein

In this study, we use solubility and drop-solution calorimetry measurements to determine the thermodynamic properties of the uranyl phosphate phases autunite, uranyl hydrogen phosphate, and uranyl orthophosphate. Conducting the solubility measurements from both supersaturated and undersaturated conditions and under different pH conditions rigorously demonstrates attainment of equilibrium and yi...

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