Transcript What are `nutrients`

The history of the living organisms
conquering land
1. The situation in the primordial sea,
400 millon years ago
Nutrients
in food
CREATCEAN SEA
Elementary
nutrients
Nutrients
in urine
What happened when the living
organisms conquered land ?
2 The situation after the first organisms had
conquered land
Nutrients
in food
Nutrients
in urine
After just a few tousand years:
Where are the green
fields my ancestors
were bragging
about?
Interlude:
What are ’nutrients’ ?
’Nutrients’ are the essential elements
needed to construct a body
These elements need to be attainable in
right proportions
E.g.: You need four times more tires than steering
wheels to build a car
Nutrients
The constituents of an animal (or vegetable) body:
H With
O gaseous
phases
C — can be
N transported
S by the air
10
times more common in the
Without
body
than in the Earth crust
gaseous
P
Na phases
More common
—
be
– phosphorus is K
the most
important
nutrient
in must
the
Earth
transported
!
crust than in
Ca as
solids or
the body
…64 liquids
Nutrients are essential for life
-- but phosphorus is the most
crucial
We need a method to use the
phosphorus molecules several
times, without losses,
so we can retain
phosphorus on land!
!
If we could transfer the
phosphorus seamless from
organism to organism without
losses to sea, we might solve it !
The regenerative cycle, basic for living systems
-- ecosystem level:
DN
A
Reconstruction
Consumption
PO
4
Urin
e
A seamless transport of
phosphorus from organism
to organism!
Recycling
Petrified newspaper
found in the
Cretaceous – Devon
geosynclinal
The regenerative cycle
High exergy
DN
Reconstruction
A
Urin
Consumption
e
PO
4
Recycling
Low exergy
Ecosystem maturation
Available solar exergy
Mature system
• Low diversity
• Annual plants
• Competition
• Parasitism
• Nutrient leakage
• Export
• Fast change
• Water export by drainage
Immature system
• High diversity
• Perennial plants
• Co-operation
• Mutualism
• Nutrient circulation
• On-site consumption
• Slow change
• Water export by evaporation
Present times
In preindustrial times, the farmland nutrients came from the
meadows
N
Phosphorus and nitrogen were collected by the meadow plants
A certain amount of meadows were needed to feed the farmland
Meadows
Feed
Manur
e
Farmland
PO
Food
4
PO
4
During industrialisation, people moved into cities
In the cities, they also needed food, food from the farms
The food contained nutrients
N
The nutrients that went away to the cities never came back
The nutrients were collected by the meadow plants
The export led to an impoverishment of the agricultural land
Manur
e
Feed
Food
PO
PO
44
PO
4
The impoverished land produced insufficient harvests
This triggered emigration
The industrialisation process might
have been halted by the loss of nutrients from farmland
Food
PO4
The situation was solved by the invention of artificial fertilizers
By that, the nutrients from the meadows became unnecessary
Even more food could be produced
Food
PO4
Food
PO4
Food
PO4
But in the cities, the situation was becoming problematic
Pollution
Pollution
PO4
Pollution
PO4
Pollution
PO4
Pollution
PO4
PO4
Food
PO4
But the invention of the piping system eased the problems
Pollution
Pollution
PO4
Pollution
PO4
Pollution
PO4
Pollution
PO4
PO4
However, at the end of the pipe, new problems were encountered
Plancton algae multiplied gladly from the new phosphorus
Pollution
Pollution
PO4
PO4
Already 50 years after the introduction of the process,
it was realised that it was the phosphorus
that caused the problems in the water
Therefore, the politicians asked the technicians for a way to
remove the phosphorus from the waste water
Pollution
Pollution
PO4
PO4
Naturally, they solved the problem in their usual expedient way
The problem
Large particle
filtration
Sedimentation
Sedimentation
Aeration
Sludge
Air
Flocculation
Rotation
Aluminum
sulphate
Filtering
Problem solved!
The problem
The problem to be solved was:
”How to get (moderately) clean water
from the polluted water?”
This problem was solved .
Problem solved!
However, the question not asked was:
”How to recycle the phosphorus
to avoid the problem?”
A large part of the phosphorus is contained in the sludge
Sludge
Food
Food
Most of the food to the city comes from very large distances
..while the phoshorus in the sludge is placed
on a much smaller area
PO
PO
4
City4
PO
4
Food
Food
Food
This means that there will be an accumulation of phosphorus
around the city
The larger the amount accumulated,
the larger the leakage
After some time, the leakage from this heap
will equal what is put on
PO
4
PO
4
PO
PO
4
4
PO
4
PO
4
PO
4
Food
Food
Food
At that time, the investment in water purification plants
becomes meaningless
PO
4
PO
4
PO
PO
4
4
PO
4
PO
4
PO
4
Food
The HEAP-effect, in a saturated system
Food
Food
When saturated, the
system leaks at the
same rate as it is
loaded
City
PO
4
PO
PO
4
4
PO PO
4
4
PO
PO
4
4
With effiecient waste
water treatment
methods
(P precipitation),
this state is attained
faster
Hampered
Effluent
Accumulation
Process
The
HEAP trap
The HEAP trap:
H ampered
E ffluent
A ccumulation
(stored
P rocess amount)
(stored
Q
kQ
amount)
Leakage
kQ=J
= input
J
Q
(leakage)
The HEAP effect
-- diffuse nutrient leakage
• Is an inevitable effect of urban
agglomerations
• Is an inevitable effect of deficient nutrent
recycling
• Can be solved by a changed settlement
infrastructure
– (or an extremenly expensive transportation system)
In an insecure situation (as in
speculations of the future)
analysis
be a good
tool
Werisk
assume
twocan
different
futures:
Our
assumptions
canbe
prove
• Energy
will always
cheap
The
different
combinations
create
(somebody
invents a little black
box with a plug and gives itwill
to everybody
for
free)
We planoutcomes
our society accordingly
•different
Right
• Energy will become expensive
•Wrong
Right
Wrong
Expensive
energy
OK
Cheap
energy
OK
OKEmbarrasing?
RIP
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