Dynamics - Phosphorous Flashcards
Most significant inorganic phosphate…
Orthophosphate
How much Phosphate is organic?
More than 90%
What is phosphate found in?
Nucleic acids/DNA backbone
Phosphoproteins
NTP
Where can phosphate abiotically be found?
Mineral phases of soils and rocks like hydroxyapatite, adsorbing into inorganic complexes like clay and carbonates
What are the four categories of phosphate?
Soluble phosphate phosphorous
Acid-solubule suspended phosphorous
Organic solluble
Organic sestonic phosphorous
Sestonic
A minute material moving in water and including both living organisms and nonliving matter.
Variability of phosphorous levels…
Low in mountain based crystalline bedrock envrionments and high in sedimentary rock deposit lowlands.
What does phosphorous increase with…
Productivity - high when lakes high level of organisms, high in presence of phosphatic rock.
Why does metal-phosphate chelation reduce phosphorous concentraitons?
Metal ion and phosphorous have differ concentrations
When might inorganic phosphorous increase?
Following and during heavy rainfall discharges and agricultural runoffs
What does P uptak correlate with?
Dominant species metabolism - low shade, benthic/plankton algae whilst shaded P associates with particles
What does organism phosphorous uptake follow?
Michaelis-Menten Kinetics
Michaelis-Menten Kinetics
An enzyme kinetics model relating reaction rate to the concentration of the substrae
Langmuir Isotherms
Describes equilibrium between gas and adsorbate phase
What does abiotic adsorption follow?
Langmuir isotherms
Example of langmuir isotherms..
Divalent metal ions (Ca/Mg) destabilise particles enhancing aggregation and sedimentation rates.
Speec of OR and IOP utilisation?
OP is slower than IOP
Phosphorous recyclign occurs…
Organically or inorganically; cell death, lysis and senesence.
What production dominantes in unshaded strems?
Autotrophic
Phosphorous inflow into lake composition?
23% leaf litter, 63% dissolved fine particulate phosphorous
What does net inflow of P into sediments depend on ?
Physical, Chemical and Biological characterisitscs.
How does sediment inflow occur?
Drainage basin sedimentation
Inorganic precipitation/adsorption
Allochtonous/autocthonous organic matter sedimentation
Benthic organisms on sedimentation
How is sediment/water exchange mediated?
Biologically with ion exchange, electron acceptor redox reactions, biotic behaviour.
How can physical processes mobilise phosphate from sediments?
Desorption, dissolution of P-compounds, ligand exchange between phosphate and hydroxide ions
How does bacterial minerlization occur?
Hydrolysis phosphate ester bonds, cell autolysis and redox condition changes
When might high sediment productivity occur?
Light penetration to sediments where benthic algae occur
What is a major external source of nutrients?
vertebrate excrement
How can phosphorous loss occur?
Sedimentation, live/dead biota, imported catchment inorganic particles.
