Dynamics - Phosphorous

Question 1

Most significant inorganic phosphate…

Answer 1

Orthophosphate

Question 2

How much Phosphate is organic?

Answer 2

More than 90%

Question 3

What is phosphate found in?

Answer 3

Nucleic acids/DNA backbone
Phosphoproteins
NTP

Question 4

Where can phosphate abiotically be found?

Answer 4

Mineral phases of soils and rocks like hydroxyapatite, adsorbing into inorganic complexes like clay and carbonates

Question 5

What are the four categories of phosphate?

Answer 5

Soluble phosphate phosphorous
Acid-solubule suspended phosphorous
Organic solluble
Organic sestonic phosphorous

Question 6

Sestonic

Answer 6

A minute material moving in water and including both living organisms and nonliving matter.

Question 7

Variability of phosphorous levels…

Answer 7

Low in mountain based crystalline bedrock envrionments and high in sedimentary rock deposit lowlands.

Question 8

What does phosphorous increase with…

Answer 8

Productivity - high when lakes high level of organisms, high in presence of phosphatic rock.

Question 9

Why does metal-phosphate chelation reduce phosphorous concentraitons?

Answer 9

Metal ion and phosphorous have differ concentrations

Question 10

When might inorganic phosphorous increase?

Answer 10

Following and during heavy rainfall discharges and agricultural runoffs

Question 11

What does P uptak correlate with?

Answer 11

Dominant species metabolism - low shade, benthic/plankton algae whilst shaded P associates with particles

Question 12

What does organism phosphorous uptake follow?

Answer 12

Michaelis-Menten Kinetics

Question 13

Michaelis-Menten Kinetics

Answer 13

An enzyme kinetics model relating reaction rate to the concentration of the substrae

Question 14

Langmuir Isotherms

Answer 14

Describes equilibrium between gas and adsorbate phase

Question 15

What does abiotic adsorption follow?

Answer 15

Langmuir isotherms

Question 16

Example of langmuir isotherms..

Answer 16

Divalent metal ions (Ca/Mg) destabilise particles enhancing aggregation and sedimentation rates.

Question 17

Speec of OR and IOP utilisation?

Answer 17

OP is slower than IOP

Question 18

Phosphorous recyclign occurs…

Answer 18

Organically or inorganically; cell death, lysis and senesence.

Question 19

What production dominantes in unshaded strems?

Answer 19

Autotrophic

Question 20

Phosphorous inflow into lake composition?

Answer 20

23% leaf litter, 63% dissolved fine particulate phosphorous

Question 21

What does net inflow of P into sediments depend on ?

Answer 21

Physical, Chemical and Biological characterisitscs.

Question 22

How does sediment inflow occur?

Answer 22

Drainage basin sedimentation
Inorganic precipitation/adsorption
Allochtonous/autocthonous organic matter sedimentation
Benthic organisms on sedimentation

Question 23

How is sediment/water exchange mediated?

Answer 23

Biologically with ion exchange, electron acceptor redox reactions, biotic behaviour.

Question 24

How can physical processes mobilise phosphate from sediments?

Answer 24

Desorption, dissolution of P-compounds, ligand exchange between phosphate and hydroxide ions

Question 25

How does bacterial minerlization occur?

Answer 25

Hydrolysis phosphate ester bonds, cell autolysis and redox condition changes

Question 26

When might high sediment productivity occur?

Answer 26

Light penetration to sediments where benthic algae occur

Question 27

What is a major external source of nutrients?

Answer 27

vertebrate excrement

Question 28

How can phosphorous loss occur?

Answer 28

Sedimentation, live/dead biota, imported catchment inorganic particles.