1.2 Resources:

1
1.2 Resources

• From waste via reuse to sustainability ?

Where are the unlimited resources? What might be
the problem to access them?
energy
Learning objective to familiarise with a
coordinated view on resources, and to understand
the context and role of sanitation.
Jan-Olof Drangert, Linköping University, Sweden
2
Reflections on water and plant nutrients

• Water molecules cannot be manufactured or
  destroyed
• Water is renewable (sun-driven cycle) everywhere
• Water available in situ (rural, peri-urban) or
  imported (cities)
• Energy supplied by humans (rural) or electricity
  (urban)
• 70 of global water use is for crop production
• A balanced diet requires a loan of 1300m3/yr p
  person based on current practice. This is 70
  times greater than the basic water need of 50 l
  per person per day.

• Phosphorus (P) cannot be manufactured or
  destroyed
• P is immobile and mined in only a few countries
• Food available in situ (rural) or mostly imported
  (cities)
• Energy supplied by humans and sun (rural) or
  fossil(urban)
• 90 of global rock P extrac-tion is for crop
  production
• A balanced diet results in depletion of 22.5
  kg/yr of phosphate rock or 3.2 kg/yr of P per
  person based on current practices, of which 0.5
  kg is found in the food.

Jan-Olof Drangert, Linköping University, Sweden
3
Input to and output from the food chain
fertilizer
rain irrigation water
manure
choice
loss
excreta
organics
agri- culture
households
no choice
evapo- transpi-ration
food
Losses on farm
Jan-Olof Drangert, Linköping University, Sweden
4
The water cycle dynamics does the trick
Instant snap shot
Shortage of freshwater !
Clouds 0.001

8 days
A dynamic perspective gives a better description
but, H2O is always on the move ...
Renewable rain gives in 2000 years as much water
as is in the oceans!!!
Rivers 0.0002
16 000 years
Lakes 0.007
280 days
Oceans 96.5
Ice caps 2.7
3 000 years
Groundwater 0.7
4 600 years
Jan-Olof Drangert, Linköping University, Sweden
5
Annual renewal and use of fresh water
Country H2O m3 /person/year km3/yr total in country Rivers from/to countries Portion being used Total use per year per person - by house-holds - by indu-stry - by agri- culture
Sweden 21 110 176 4 2 479 m3 36 55 9
Holland 680 10 80 16 1 023 m3 5 61 34
Saudi Ara 160 2 0 164 255 m3 45 8 47
Lebanon 1 620 5 -1 16 271 m3 11 4 85
India 2 170 1 850 235 18 612 m3 3 4 93
Tanzania 2 780 76 0 1 36 m3 21 5 74
Kenya 590 15 0 7 48 m3 27 11 62
Egypt 30 2 56 97 1 202 m3 7 5 88
USA 9 940 2 478 0 19 2 162 m3 12 46 42
Chile 35 530 468 0 4 1 625 m3 6 5 89
China 2 470 2 800 0 16 462 m3 6 7 87
Source P. Gleick, 1993
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Global scarcity of plant nutrients - a new
driving factor for sanitation

• Phosphorus is a limited resource, and large
  untapped reserves will eventually only be found
  on sea shelves and as anthropogenic depositions
  in lake sediments.
• 95 of mined potash goes to the fertiliser
  industry and has no substitute. Mines exhausted
  in some 50 years.
• 60 of mined sulphur goes to fertilizer industry
  and has no substitute. Mines exhausted in some 20
  years.
• Costly to recover these plant nutrients from lake
  sediments compared to trapping them directly at
  the source i.e.as output from households and
  industries.
• Nitrogen can be manufactured from the N in the
  air, but this requires much energy (1 litre of
  oil to produce 1 kg of nitrogen).

D. Cordell J-O Drangert, Linköping University,
Sweden
7
Phosphate Rock Worldwide Estimates (thousands
of metric tons)
P scarcity is worse than oil scarcity because P
CANNOT be substituted in food production
Courtesy of Ian Caldwell, Stockholm Envrionment
Institute, Sweden
8
Food, water and nutrient flows
transpiration evaporation
0.9 l
H2O
1.5 l
food
1.1 l
Urine 1.5 l
Faeces 0.15 l
nutrients
Virtual water 4 cu.m.
nutrients
Jan-Olof Drangert, Linköping University, Sweden
9
NUTRIENTS and demography
Billion people
9
World Total 16th - 21st century

6
21th century
20th century
urban
3
rural
1500
1600
1700
1800
1900
2000
2100
Jan-Olof Drangert, Linköping University, Sweden
10
Actual reuse of nutrientsfor urban agriculture
food security (in Swedish towns 1850 2000)
Proportion nutrients being reused
100
Glass, tins, ceramics
Heavy metals
50
waste pits
urine diversion
WC
stop
only WC
WWTP
1870
1910
1950
2000
Jan-Olof Drangert, Linköping University, Sweden
11
Human resources capacity to manage sanitation
arrangements
Level of management
WWTP,
biogas
Utility
flush toilet,
water supply,
sewerage
Organic waste
sewerage
drainage
wetland
urine-diverting toilet
septic tank
Grease trap,
Household
Organic waste
pit latrine
biogas
User contribution
Work hours
Paying fees
Jan-Olof Drangert, Linköping University, Sweden
12
Manpower blindness driver of new
responsibility sharing
Our pre-conceived views play a role

• We tend to account only for what is done by
  governments and projects in water and sanitation
• What is done by residents and small
  entrepreneursis rarely appreciated, if at all
  recognized (blindness)
• Yet, many urbanites survive thanks to such local
  initiatives
• Here, we pledge that both kinds of activities are
  needed to solve current sanitation problems

Jan-Olof Drangert, Linköping University, Sweden