Ecological engineering draws on natural processes to address environmental problems. It relies on principles like: 1) Energy signatures that determine ecosystem structure and function, such as sunlight or organic matter inputs. 2) Self-organization through ecological succession as species colonize and evolve based on available resources. 3) Preadaptation of species that are adapted to the intended ecosystem conditions, accelerating development. Wetlands are an example where the microbial communities in the water and substrate break down pollutants through natural treatment processes like sedimentation, filtration, and biochemical reactions. Different wetland designs like free-water surface, horizontal subsurface flow, or vertical flow can be used to treat wastewater depending

1. Principles of
Ecological Engineering
Rahul K Kamble

2. Background
• Ecological engineering draws on traditional
technology for parts of design
• Traditional technology contributes half and
remaining half by ecology
• Other types of engineering applications
address environmental problems but with less
contribution from nature e.g. wastewater
treatment and chemical engineering

4. Principles of EE
• Energy signature (Forcing function)
• Self-organization (Ecological succession)
• Pre-adaptation (Pre existing features)

5. Energy signature (Forcing function)
• A set of energy source which determines
ecosystem structure and function
• Those outside causal forces that influence
system behavior and performance
• Number of different types of energy sources
affects ecosystem.

7. • Autochtonous (sunlight driven) vs.
allochthonous (detritus inputs from outside
the ecosystem)
• Auxiliary energies: Any source of energy
reduces the cost of internal self maintenance
of the ecosystem (other than sunlight and
organic matter).
• Energy and work (Thermodynamics-ability to
do work).
• Different energy-different work

8. • Each energy signature  unique kind of
system to develop.
• One-to-one matching of energy signature 
design, construction and operation of EE.
• An appropriate energy signature exists to
support the ecosystem that is being created.
• Subsides can be added e.g. water, fertilizer,
aeration, turbulence (ecosystem to develop)
• Stressor can be added e.g. fertilizer (limit
development).

9. Self-organization
(Ecological succession)
• Self organization applies to the processes by
which species composition, relative
abundance distribution and network
connection develop over time.
• This is commonly called as ecological
succession.
• Mechanism of it in an ecosystem, is form of
natural selection of those species that reach
the site (specific area) through dispersal.

10. • Species that successfully colonized is due to
finding a set of natural resources and
favorable environmental conditions.
• This conditions support a population of
sufficient size for reproduction.
• Darwin evolution occurs within all populations
while self-organization occurs between
populations within the ecosystem.
• Ecosystems are the workshops of evolution.
• Ecosystem is a selection machine working
continuously on a set of populations.

11. Preadaptation
• Self organization can be accelerated by
seeding with the species that are
preadaptation to a special conditions of the
intended ecosystem.
• E.g. designing an ecosystem to treat acid
drainage from coal mines

12. Performance curve of adaptation

13. • Preadaptations are preexisting
conditions/features that make organisms
suitable for new situations.
• “Taking-advantage of situation”
• Preadpation is an apparently random
phenomenon in nature.
• These species accelerate the development of
useful systems and lead to improved
performance.

14. • New ecosystems developing with pollution
are sources of preadpated species for
treatment ecosystem.
• Invasive, exotic species often are successful
due to preadaptation to human disturbance
 can be useful in EE.

15. Ecological engineering for SWM
• Humans generate solid waste as a byproduct
from all activities
• Disposal of these wastes are challenging one
• Solid waste consists of diversity of objects
• Material from different sources are collected
and mixed to form municipal solid waste

16. Composition of solid waste

18. Cross section view of
sanitary landfill

19. Sequential production dynamics of
gases from a sanitary landfill

20. Energy circuit diagram of
sanitary landfill

21. Composting
• Composting is the process used to breakdown
organic solid wastes into materials that can be
reused as soil amendments in agriculture and
horticulture.
• Organic wasted that are composted include
food waste, sewage sludge, yard waste, and
animal manure.
• Goal is to maintain aerobic conditions that are
insulated to retain heat and to allow access by
decomposer MO.

22. Composting
• Wide variety of systems ranging from large-
scale commercial facility that are highly
engineered to small-scale backyard systems
used by gardeners.

23. Composting

24. Steps in composting process
1. Separation of refuse into compostable and
non compostable
2. Shredding
3. Blending
4. Digestion
5. Product up-gradation
24

25. • Ratio of C:N is most important one
• Optimum ratio for composting is about 25:1 to
30:1.
• Protein materials (food waste) breaks down
easily, support MO.
• Materials such as cellulose, lignin, or aromatics
breakdown slowly.
• Composting is an example of ecological
succession.
• Series of microbial taxa contribute to breakdown
of organic waste in an organized sequence

26. • Composting is interesting example of succession
because of biogenic changes in temperature.

28. A: Mesophilic MO- aerobic/anaerobic- Metabolize carbohydrates such as sugars,
starches, Temp. 35o
C
B: Thermophilic MO (Heat leaving)- metabolize protein and other N waste, Temp.
60o
C, no MO can exists above 70o
C.
C: Cooling down stage, actinomycetes and fungus population increases-
metabolize cellulose/more resistant carbon compounds.
D: Humus formation

29. • In mechanized composting complete
ecological succession sequencing takes place
in one week
• In open window operation takes a month to
complete the same.

30. Treatment wetlands
• Water is an indispensible part of human life
• Water requirement for domestic, industrial
and agricultural purposes
• On an average an individual requires about
130 L of water per day
• Large quantity of wastewater is generated
• Wastewater treatment is not carried out at
many places

31. • Typical wastewater treatment includes:
Preliminary, Primary, Secondary (Biological)
and Tertiary (Advanced) wastewater
treatment

33. • These treatment technologies has some
bottlenecks viz. technology, cost, skilled
human resource, efficiency, etc.
• Thus, some other methods needs to be
adopted  Treatment wetlands
• Wetlands are land areas that are wet during
part or all of the year because of their location
in the landscape.
• Also called as swamps, marshes, bogs, fens, or
sloughs.

34. • Wetlands  higher rate of biological activity
than most ecosystem  can transform many
of the common pollutants in wastewater 
into less harmless byproducts or essential
nutrients.
• Wetlands are least expensive treatment
system to operate and maintain
• Minimum fossil fuels and chemicals are
typically necessary to meet treatment
objectives.

39. Figure: Free Surface Water
Steps involved: Sedimentation, Filtration, Oxidation, Reduction, Adsorption,
Precipitation

40. Figure: Typical application of a FWS wetlands for municipal wastewater treatment

41. • FWS closely mimic natural wetlands
• Attract wide variety of wildlife's, namely
insects, mollusks, fishes, amphibians, reptiles,
birds, mammals.
• FWS  potential for human exposure for
pathogens; rarely used for secondary
treatment.
• FWS are most commonly used for advanced
treatment.

42. Figure: HSSF wetland schematic
Horizontal subsurface flow

43. Figure: Application of a HSSF wetland
Horizontal subsurface flow

45. • In HSSF wastewater is intended to stay beneath
the surface of media and flow in a around the
roots and rhizomes of the plant
• Wastewater not exposed to  risk associated
to human or wildlife is minimized.
• HSSF wetlands are more expensive than FWS
• HSSF for smaller flow rates than FWS wetlands
• HSSF wetlands comprised of inlet piping, clay
or synthetic liner, filter media, emergent
vegetation, berms, outlet piping with water
level control

46. • HSSF wetlands have a limited capacity to
oxidize ammonia, because of limited oxygen
transfer

47. Figure: Typical arrangement of vertical flow constructed wetlands
Vertical flow

48. Figure: Typical arrangement of vertical flow constructed wetlands
Vertical flow

49. Figure: Typical arrangement of vertical flow constructed wetlands
Vertical flow

50. • VF wetlands ability to oxidize ammonia
• Thus, applied to higher ammonia than
municipal or domestic wastewater
• Very concentrated wastewater can be treated
in VF systems.
• In wetlands, most bacteria are associated with
solid surfaces of plants, decaying OM and soils.
• Fungi are typically found growing in association
with dead and decaying plant litter

51. • Microbial metabolism includes the use of
enzymes to breakdown complex OM or
synthesis of organic compounds.