Transcript Sustainable Sanitation for the 21st Century

2.2 Major changes over time
Source: Rathnabharathie and Kariyawasam, 2007
Learning objective: gradual long-term
changes in sanitation arrangements
and tracing origins of change.
Jan-Olof Drangert, Linköping University, Sweden
Was the strong link between water and
sanitation in the 20th century a brief detour
in human history?
Most
common
agriculture
+
sanitation
All rural
What will
come next ?
water
+
sanitation
agriculture
+
sanitation
Essentially urban
Jan-Olof Drangert, Linköping University, Sweden
Urine-diverting
toilet in the 1860s
and sanitation
footprints 1910
faeces
vent
pipe
urine
collector
60km
urine bowl
urine
funnel
Stockholm
Jan-Olof Drangert, Linköping University, Sweden
How pipes gradually took over waste transport
Period
Solid waste
waste
Solid
street-
1800
kitchen-
Wastewater
Excreta
faeces
urine
Earth pits for all household waste and content
emptied in garden or on nearby farm
Latrine
buckets of
metal
Disposed of in
streets or in yard
1870
Disposed of in
streets or in yard
1900
Container for solid
waste
Black (WC)- and greywater in pipe to water body
without any treatment
1950
Solid waste incinerated
Some garbage sorted
Wastewater treatment plants being built
1970
2000
Sorting of garbage
and reuse
Urine and greywater to a septic
tank/waste pit or straight to water body
Some sludge applied on farmland
Scenario 1: grinder for organic kitchen waste, increased mixing
of waste and incineration of the sludge
Scenario 2: garbage sorted in more fractions, which are
treated separately and used in production of new products
Jan-Olof Drangert, Linköping University, Sweden
The history of management of water and used
water over the 20th century and beyond
1970
Supply
Management
Demand
Management
Reuse
Management
Priority 1: provide
water
2000
no longer the only concern
Priority 1: reduce
water volume and
emerging interest in wastewater
Pri 1: wastewater
quality
Jan-Olof Drangert, Linköping University, Sweden
Mexico City now has 20+ million people
MC
Latest opened
water source
1 km
100
km
Next?
2 km
200
km
Courtesy of Ian Adler, International Renewable Resources Institute, Mexico
Jan-Olof Drangert, Linköping University, Sweden
What we have seen so far …..
• More pipes and more mixing of various flows
has been the mantra for a long period
• But of late, there is a slow shift in focus from
supply issues to what happens to water and
waste materials after they are used
• New focus: to improve the way we deal with
excreta, organic solid waste and wastewater in
order to treat and use these resources again
• The future sources of water and nutrients will
come from reusing water and waste materials
Jan-Olof Drangert, Linköping University, Sweden