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KA40803 - Advanced Environmental Engineering

Topic : Ecosystems and Energy Flows

By Dr. Nurmin Bolongnurmin@ums.edu.my

Learning outcome

This topic will provide the learners with the ability to:• Explain ecosystem & its role and importance

to environmental engineer• Identify and analyze energy and material flows• Distinguish the Circulation of energy and

matter in human

• List out the meaning/definition of an ecosystem…

5-10 min

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• An ecosystem consists of the biological community that occurs in some locale, and the physical and chemical factors that make up its non-living or abiotic environment

http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/ecosystem/ecosystem.html

• An ecosystem is a community of living organisms (plants, animals and microbes) in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system

Tansley (1934); Molles (1999), p. 482; Chapin et al. (2002), p. 380; Schulze et al. (2005); p. 400; Gurevitchet al. (2006), p. 522; Smith & Smith 2012, p. G-5

Eco?• a prefix mostly relating to ecological or environmental termsSystem?• a set of connected things or parts forming a complex whole, in

particular.• a set of things working together as parts of a mechanism or an

interconnecting network.• a set of organs in the body with a common structure or

function.(physiology)• a group of related hardware units or programs or both, esp. when

dedicated to a single application. (computing)• a set of principles or procedures according to which something is

done; an organized scheme or method. (organization)

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Ecosystem processes

List the processes, and explain(at least one – provide your reference)*do make sure no duplication with other friends/team

Work in group (3-5) 10-15 min task

Write down and explain

10 mins+ 10 mins

• Study of plants, animals, and their physical environments – and how energy-materials behave in ecosystem

• Ecosystem → complex yet possible to be narrowed and linked to the role u are in. (ie. Engineers, Geologist, zoologist, scientists, etc)

Remarks!

STD PROJECT: PRESENTATION topic:TOPIC #1-Discuss two examples of ecosystems and explain the connection towards current global issues.

20 min

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STD PROJECT- Presentation on: TOPIC#2 Human activities impact on ecosystems and environment. Why we as engineers should care.

10 mins+ 10 mins

Environmental engineers need to consider the ecosystems impacted by designs-by incorporating the expertise of professionals in other disciplines

Black bear in south carolina

An example of a bear-proof trash can in Shenandoah national Park, USexample

Energy & material flows in ecosystem

• Inside ecosystem – both energy & materials flows with fundamental difference– Energy flow only in one direction– Material flow is cylndrical

[Nutrients] + CO2→ → → O2+ [high energy molecules]

All energy originates from sun (as light energy)

sunlight

Example in photosynthesis (simple way)

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An Example of a one-way flow of energy

Rate of energy extracted or decreasingAnd NOT recycled

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An Example of a nutrient flow through an ecosystem

Start with dead organic (also termed as detritus)

Produces compounds as ammonia etc

Stabilized or fully oxidized & forms as a more stable compounds

CO2 use by plants & others as nutrients

Plants then die or use by other

Formation of new plant tissue

3 types of microbial decomposers:• Aerobic• Anaerobic• facultative 5 min

think & answer

What are major properties?

[detritus]+O2→CO2+H2O+[nutrients][detritus]→CO2+CH4+H2S+NH3+….+[nutrients]

Facultative – use oxygen when available and also can use anaerobic reactions if not available

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The arrow shows how energy is received from the sun and flows through the system

Balance equation: [IN]=[OUT]

Human influence on ecosystem

(1) Effect of pesticides• Organic pesticides such as

DDT• Decomposed very slowly• Stored in fatty tissus of

animals – transferred through food chain

Biomagnified in the food chain

Data from Woodell, G.M et al, 1967, Science 156:821-824

Human influence on ecosystem

(2) Effect of nutrients on a lake• Model of lake shows the

producers (algae) receive energy from sun (photosysthesis) –produce biomass & oxygen

• Consumers: fish, plankton etc –use oxygen & produce CO2, transfer nutrients

• Decomposers: eg worms, microorganism also respire (use energy) & use oxygen & produce CO2

• When not in balance –eutrophication can be reversed

ALGAE

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Human influence on ecosystem

(3) Effect of organic wastes on a stream• Problem also due to oxygen

depletion• Water can hold only limited

amount of gas; amount of oxygen can be dissolved depends on :– water temp, atms pressure,

concentration of dissolved solids

Stream – flushed out compared to lake

Ref: Vesilind, Morgan, Heine; 2011

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Mechanism of re-aeration in natural streams (constant noted as k)

consume

If the rate of oxygen use> the dissolved oxygen level drop (cannot keep up with oxygen consumption)=Deficit (D)

Deficit (D) = saturation of oxygen in water (S)-Concentration of DO (C)

Unit mg/L

[IN]=[OUT]Qs+Qp=Q0

S=upstreamp=pollution source

0=downstream

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Human influence on ecosystem

(4) Effect of Design on an ecosystemRemodel & incorporate :• energy-efficient• Water-efficient• Environment-friendly

materials• Green and sustainable

design

Example?

5 min think & answer

Energy flows and balances

Flow of energy in the living ecosystem

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More example of energy flow occurrences

Energy is NEVER produced or consumed – but changed form

[Rate of energy IN] = [Rate of energy OUT]

The first law of thermodynamics: The total amount of energy in the universe can neither created nor destroyed, only exchanged.

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A power plant uses 1000 Mg of coal per dayThe energy value of the coal is 28,000 kJ/kgThe plant produces 2.8 x 10exp6 kWh of electricity each dayWhat is the efficiency of the power plant?

Try!(ans: eff=36%)

The Circulation of Matter and Energy

• Humans being will always seek to improve their quality of life, and without doubt, this will harm the environment.

• The Earth’s entire biosphere can be viewed as a single, self-regulating “body” as which will react to disturbances much as a human reacts to attack by disease - Gaia Hypothesis - (such as extreme weather)

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THANK YOU