chapter one history and philosophy 2 (1)
TRANSCRIPT
Chapter one
Wetlands for Water Quality
History and philosophy of the
use of wetlands for
wastewater treatment
Wetlands for Water Quality
Learning objectives
• At the end of this chapter participants will be able to:
• Know something about the history of constructed
wetlands
• Know the prerequisites for treatment of wastewater in
natural systems
Chapter one
Contents
• Origin of constructed wetlands
• Advantages natural systems
• Philosophy and context
• Prerequisites of use of natural
systems
Wetlands for Water Quality
Chapter one
Wetlands for Water Quality
History and philosophy of the
use of wetlands for
wastewater treatment
By Professor Diederik Rousseau
University of Gent, Belgium
Tänassilma wetland
(Estonia)
OLC Constructed Wetlands
Origin of constructed wetlands
Use of wetlands for wastewater treatment
Casual experiments
+
(Kangas, 2004)
Rise of ‘green movement’
+
First energy crisis (1973)
+
OLC Constructed Wetlands
Comparison of the energy inputs to natural and conventional
wastewater treatment technologies
Natural systems Conventional systems
Sun
Wind Land
Seeds Concrete
Steel Electricity
Chemicals
SoilsPlants
Microbes
Microbes
Advantages of natural systems
OLC Constructed Wetlands
Use of wetlands for wastewater treatment
Distrust of new technogies
-
Casual experiments
+
First energy crisis (1973)
+
(Kangas, 2004)
Rise of ‘green movement’
+
Origin of constructed wetlands
OLC Constructed Wetlands
Wetlands for Water Quality
(Kangas, 2004)Big bang model
(Kangas, 2004)
1970 Optimism and enthousiasm
1980 Cautiousness and scepticism
1990 Full-growing
2000 Commercialisation
Evolutionary phases of constructed
wetlands’ evolution
OLC Constructed Wetlands
Scandinavia
Bolivia
Vietnam
Canada
Australia
New
Zealand
Tanzania
Belgium
USA
India
South Africa
Application throughout the world
OLC Constructed Wetlands
Wetlands for Water Quality
Converting wastewater in useful products
Philosophy and context
Fish cum duck
Fish cum chicken
Fish cum pig
Example: wastewater aquaculture
OLC Constructed Wetlands
• Sufficient incident light
• Temperature not too low
• Adequate quantities of nutrients
• Waste water not toxic
• Detention time long enough
• Organic loading not too high
• Need for enough space
Prerequisites for natural systems
OLC Constructed Wetlands