Dmitri

Question 1

What is environmental awareness?

Answer 1

• Being aware that our actions have an impact on the environment and that we have a responsibility to protect it as much as possible.
• As citizens: contribute to governance and citizen/consumer actions to protect the environment’s state e.g recycling
• As engineers: provide solutions to tackle environmental issues, minimise the impact of our work, tech and solutions proposed, stimulate, participate in public debate and pass on knowledge.

Question 2

Importance of environmental awareness

Answer 2

• key notion is finite resources
• protecting ecosystems that provide us with renewable resources important to survival
• disruption, pollution, intensive reliance leads to imbalance

Question 3

What is ecological footprint?
Critiques and problems?
Helps with what?

Answer 3

• Quantifies the land needs to regenerate our impact on the environment
  Problems:
• biodiversity, social, economic and well-being factors are hard to quantify
• should be used as a reflection or discussion tool
  Helps:
• understand the magnitude of potential impact of our activities
• assess, discuss and compare potential ways forward
• awareness tool for communicating the importance of environmental protection

Question 4

Morse community and Easter Island examples

Answer 4

Morse community and Easter Island, former small settlement from Iceland that covered Greenland, and remote island in the pacific. Unknown why these communities disappeared. Likely that they over exhausted their natural resources e.g overhunting, overuse of trees for fuel leading to soil erosion and loss of habitat.

Question 5

Industrial revolution impact

Answer 5

Sometime around 1760, the industrial revolution disrupted the previous way of living in occidental societies and led to the anthropocene. Textiles, steam power and transportation, chemicals, economies of scale lead to large scale industrialisation which in turn enabled better quality of life and hence an increase in population and an increase in GDP. Later on, this enabled the large scale and widespread extraction of fossil fuels that in turn allowed other significant revolutions to take place such as the ‘green revolution’ of agrochemicals and food production, plus the ‘white revolution’ with modern medicine and chemicals.

Question 6

Definitions of

• biodata
• biosphere
• ecosystem

Answer 6

• Biodata: general term used to refer to all living things within a given area
• Biosphere: the region of Earth where life exists
• Ecosystem: a community of living organisms and its local non-living environment where matter cycles and energy flows occur

Question 7

Important characteristics of living organisms

Answer 7

• cellular structure
• reproduction
• metabolism (transformation of energy by conversion of chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism))
• growth
• adaptation
• response to stimuli
• homeostasis

Question 8

Carbon cycle

Answer 8

Contained in fossil fuels, earth’s crust, soils, plants, oceans, atmosphere
Released by burning fossil fuels, soil respiration, plant respiration, volcanoes, deforestation and land use change, ocean loss
Used up by ocean uptake, rivers, litterfall, photosynthesis

Question 9

The Gaia hypothesis

Answer 9

The hypothesis states that the biosphere is able to regulate itself and keep the planet healthy through control of the chemical and physical environment. Living systems themselves form the elements of this ‘system/machine’. Proposed that organisms and their surroundings evolved together as a single living system.

Question 10

Evidence proposed in favour of Gaia hypothesis

Answer 10

• Presence of oxygen in the atmosphere and its regulation. It is believed that the appearance of oxygen in our atmosphere occurred as a result of the evolution of photosynthetic life forms, which then allows for the support of most species and ecological processes. In addition, the concentration of oxygen in the atmosphere has been stable for a very long time. This suggests an equilibrium between production by plants and consumption by both living and non-living processes,, regulating to attain required conc. For example, at 25% conc would be harmful as would result in more forest fires. Remains from ancient forests show below 25% conc.
• Exchange of critical elements between land, sea and atmosphere. Ocean salinity has been constant at approx. 3.4% for a very long time. Most organisms require constant conc. and would not be able to tolerate much higher than this. It is thought that biological processes, involving the fixation of ions and heavy metals by bacterial colonies keeps this stable, desirable conc.
• Surface temperature regulation: energy provided by the sun has increased between 25-30% since the appearance of first life forms. Hypothesised that methanogens increased methane concs to keep warm. Surface temp has remained within the levels of habitability.

Question 11

Daisy world model

Answer 11

Model shows how a simple response of a living species to changes in its temp can modify its environment. Simulation of a hypothetical Earth-like planet populated by daisies - black and white both with the same temperature requirements for growth. The star daisyworld orbits progressively got brighter and brighter, radiating more heat. However, the surface temperature did not change. This was because the daisies were able to moderate the temperature through their ability to absorb/reflect light. To begin with, lots of black daisies to absorb light, but decreased as luminosity increases and reflecting white daisies increase.

Question 12

Extension of daisyworld model that supports the idea that biodiversity is valuable

Answer 12

Later extensions of the simulation included other species such as rabbits, foxes etc. Increasing the number of species improved regulation, supporting the idea that biodiversity is valuable.

Question 13

Factors capable of destroying all life on Earth

Answer 13

• Nuclear explosions:
  small scale compared with natural events e.g earthquakes
  temp and blast effects localised
  radiation effects severe for higher animals, much less significant for microorganisms
• Chemical pollution
  short term effects usually localised
  toxic effects vary from species to species
  subtle and long term effects difficult to quantify and assess, effect on atmosphere, climate, fertility
• Biological warfare
  likely to be highly selective for higher animals
  possible effects on food crops
  unlikely to affect micro-organisms
  effects limited by biological diversity
• Genetic engineering
  similar constraints to biological warfare
  limited viability in the environment
  possible hazards resulting from transfer of abilities to other species
  exchange of genetic materials is a natural process
  unknown effects and improper use
• Natural disasters
  earthquakes
  volcanoes
  comet strike

Question 14

What is biodiversity?

Answer 14

Commonly used to describe the variety of living organisms of all kinds that inhabit a particular area. Most commonly, it is measured by the no of species present in an ecosystem, but genetic diversity within those species and the diversity of diff ecosystems across the landscape are also important. Biodiversity is many cases is critical to the well being of ecosystems.

Question 15

Ecosystem services

Answer 15

• Provisioning
  food, fresh water, wood and fibre, building materials, air in terms of oxygen from photosynthesis
• Regulating
  climate regulation, flood regulation, disease regulation, water and air purification
• Cultural
  aesthetic, spiritual, educational, recreational

Question 16

Biodiversity - effect of natural environment

Answer 16

Species diversity in natural habitats is high in warm areas and decreases with increasing latitude and altitude. On land, diversity is higher in areas of high rainfall and lower in drier areas. The richest areas are undoubtedly tropical moist forests.
- microfauna of tropical moist forests -> 90% of species on only 7% of world’s surface area
- a biodiversity hotspot is a geographical region that is both a significant resevoir of biodiversity, and is threatened with destruction
34 hotspots identified by conservation international cover 2.3% of the Earth’s land surface, contain more than 50% of the world’s plant species, and approx 42% of all terrestrial vertebrae -> many threatened by human activity

Question 17

Loss of biodiversity

Answer 17

At its most fundamental and irreversible level, loss of biodiversity involves the extinction of species, and over geological time, all species have a finite span of existence. Thus, species extinction is a natural process that occurs without the intervention of humans. Extinction caused directly or indirectly by humans are occurring at rates which far exceed any reasonable estimates of background extinction rates.

Question 18

Indicator species in biodiversity

Answer 18

Certain species can serve as indicators of the health of ecosystems. A species may be used as an indicator or ‘key stone’ species given that they fulfil two criteria:
- an indicator species should be extremely sensitive to environmental distress
- an indicator species should be relatively abundant in the community being monitored
In the Canadian Arctic, these criteria are met by polar bears -> ice melting, bears have less time for hunting, difficult for them to survive

Question 19

Human causes of loss of biodiversity

Answer 19

• overexploitation e.g fishing rate much higher than reproduction rate
• habitat destruction and modification through development and agriculture
• pollution
• climate change

Question 20

Climate change and loss of biodiversity

Answer 20

UN intergovernmental panel on climate change (IPCC) report (Oct 2018): Urgent warning that there is only a dozen years for global warming to be kept to a maximum of 1.5 degrees, beyond which even half a degree will significantly worsen the risks of draughts, floods, extreme heat and poverty for millions.
Specific to biodiversity:
- Arctic sea ice would remain during most summers if warming is kept at 1.5, but at 2, ice free summers are 10x more likely leading to greater habitat loss for polar bears, whales, seals and sea birds
- coral reefs will still decline by 70-90% but at 2 degrees virtually all of the world’s reefs would be lost

Question 21

Maintaining biodiversity

Answer 21

• ‘on-site management’: protection and preservation of national parks contributes to economy whilst also protecting species
• ‘off-site’ management:imposing a price on natural resources and ecosystem sources
• governments’ encouragement of schemes with involvement of industrial companies e.g coca-cola has been working with environmental organisations to conserve key watersheds and improve the efficiency of its water uses

Question 22

Mitigation strategies

Answer 22

Most desirable:

• Avoid; avoiding impacts by modifying a proposed site or existing operation in order to prevent or limit a possible impact. Changing the location at design of a processing plant is simple example.
• Minimise; actions to minimise during design, construction or operation. Implement decisions or activities that are designed to reduce the undesirable impacts of a proposed action on biodiversity. For example, installing tertiary treatment to remove phosphates from effluents that could lead to eutrophication of wetlands and changes in species conservation
• Rectify; post development remediation. Rehabilitating or restoring the affected environment, one example is Richards Bay minerals’ efforts to restore dune habitats after the extraction of titanium dioxide from coastal sand dunes in South Africa.
• Compensate; provision of substitute resources or environments. Compensatory measures should be used as a last resort, and might include so-called offsets such as purchasing an area of equivalent habitat for longer term protection. An example is the Flambaeu Copper mine in Wisconsin, this was originally planned as a copper mine and concentrator. Would have extracted ore at 1% copper and turned it into concentrate at 30% copper -> would have led to a large volume of wet fines having to be stored on site forever. Preventing acid drainage developing was a serious community concern in view of what they considered to be the biorich Wisconsin river and its surroundings. So was backfilled and reseeded.The eventual plan was to mine the ore at a higher grade and sell the ore to Canada to an existing facility. This meant that the return for the company was reduced and that some copper was left behind that might well have been mined had there been a processing facility on site.

Question 23

Why conserve biological diversity?

Answer 23

-The present and potential use of elements of biodiversity -> biological resources
-The maintenance of the biosphere in a state supportive of human life
-The maintenance of biological diversity is the ethical responsibility of humans as a resource:
a certain level of biological diversity is necessary to provide the material basis of human life;
to maintain the biosphere as a functioning sytem
to provide the basic materials for agriculture and other utilitarian needs.

Question 24

Food & biodiversity

Answer 24

Although a relatively large no of plant species (>1000) have been used as foodstuffs, only a small % of these are nutritionally significant on a global level, and only v few of these have been intensively managed on a commercial scale. Similarly, many animal species are eaten but only a small % are of global nutritional significance. So:

• living environment of these plants and species, they can’t survive without other species
• insurance policy: need substitutes

Question 25

Pharma & biodiversity

Answer 25

Drugs derived from natural sources make an important global contribution to health care. Some 120 chemicals extracted in pure form from approx 90 species used in medicine throughout the world. Chewed willow tree bark, used to alleviate aches and tooth pains led to the discovery and synthesis of acetylsalicylate -> aspirin.
The majority of antibiotics in current use are naturally produced by either bacteria or fungi. These organisms produce antibiotic compounds in order to compete with other microorganisms within their environment, particularly soil. The accidental discovery of penicillin in the 30s sparked a massive drive to examine 1000s of species of bacteria and fungi for new compounds that could also act as antibacterial agents.

Question 26

Other material values of biological diversity

Answer 26

The role of forests in watershed regulation and stabilisation of soils in erosion-prone areas
The role of coral reefs in supporting important fisheries
The role of natural ecosystems protected as national parks in generating income from wildlife tourism

Question 27

The precautionary principle (insurance)

Answer 27

A relatively small proportion of the world’s biological diversity is actively exploited by humans, other elements of biological diversity may be important for diff reasons:

• they may have values which are unknown or unused which may be discovered and exploited
• they may become useful or vital at some time in the future owing to changing circumstances
• they may be critical for supporting life forms that are exploited by humans

Question 28

The sustainable development challenge

Answer 28

Continuing to grow the world’s economies to alleviate poverty without destroying the fundamental ecological systems that sustain life as we know it.

Question 29

Definition of pollution

Answer 29

The direct or indirect introduction, as a result of human activities, of substances, heat, noise or vibration, into the air, water or land, which may be harmful to human health, or the quality of the ecosystem, or result in damage to material property, or impair or interfere with amenities and other legitimate uses of the environment.

Question 30

Primary pollutants and secondary pollutants

Answer 30

• Primary: exert harmful effects in the form in which they have been released into the environment.
• Secondary: product of chemical reactions occurring in the environment, usually between less harmful precursors.

Question 31

Global distillation of pollutants

Answer 31

At low latitudes, evaporation of pollutants exceeds deposition, pollutants are transported by the atmosphere and oceans. At high latitudes, deposition of pollutants exceeds evaporation. Pollutants enter the polar food web and accumulate in biodata.

Question 32

Environmental toxicology

Answer 32

An interdisciplinary science concerned with the study of natural and anthropogenic pollutants and their impact on living organisms and ecological systems.

Question 33

Bioaccumulation

Answer 33

An increase in the conc of a chemical in a biological organism over time compared to its concentration in the environment. Compounds accumulate in living things when they are taken up faster than they are metabolised or excreted. Understanding the dynamic process of bioaccumulation is important in protecting human beings and other organisms from the adverse effects of chemical exposure and it has become a critical consideration in the regulation of chemicals.

Question 34

Biomagnification

Answer 34

A process that results in the accumulation of a chemical at higher levels than are found in its food. Occurs when a chemical become more and more concentrated as it moves up through a food chain.

Question 35

3 levels of minimising environmental impact

Answer 35

• Microscale: molecular interaction e.g for catalysed reactions: development of new reactions that are more selective, reducing loss and waste of feedstock. On chemical level -> try find reactions that produce no waste.
• Mesoscale: unit and plant operations e.g a reactor. Minimise or eliminate the formation of side products including pollutants. By-products are considered waste. Can alter reactor configurations process conditions
• Macroscale: industry sector. Everything is considered e.g LCA, raw materials -> disposal, consideration of interactions with environment.

Question 36

What is waste minimization?

Answer 36

Any management or process modification that ultimately reduces the mass or toxicity of waste sent to storage, treatment and disposal facilities.

Question 37

Waste definition

Answer 37

a) any substance which constitutes a scrap material or an effluent or other unwanted surplus owing from the application of a process
b) any substance which requires to be disposed of as being broken, worn-out, contaminated or otherwise spoiled.

Question 38

Green chemistry

Answer 38

Prevention of waste
Atom economy
Less hazardous reactions
Safer products
Safer solvents (or no solvents)
Energy efficiency: ambient T and P
Renewable feedstock
Avoid derivatisation
Catalysis, not stoichiometric reagents
Design for degradation
Real time online monitoring
Inherently safer chemistry

Question 39

Industrial ecology

Answer 39

To link a number of processes via their material and energy streams, so as to minimise the overall use of non-renewable resources without comprimising the delivery of services.

Question 40

Factors other than cost that affect materials recovery

Answer 40

• Availability of collection network

- Availability of process technology

Question 41

UNEP deifnition of life cycle approach

Answer 41

A conceptual approach to production that demands that all phases of the life cycle of a product or a process should be addressed with the objective of prevention or minimisation of short and long term risks to human health and to the environment - complete supply of energy and materials leading to the product or process must be considered - including the disposal of the product and decomissioning.

Question 42

Formation of CO and NO

Answer 42

CO produced as by-product during incomplete combustion:
HC + O2 -> CO + CO2 + H2O which takes place in the internal combustion engines of motor vehicles that operate at certain air to fuel ratio.
NO is produced because of high temp due to the combustion of fuel:
N2 + O2 -> NO
NO levels in exhaust gases are critically dependent upon the peak combustion temp

Question 43

Abatement of NO from stationary sources

Answer 43

NH3 over vanadia catalyst, excess of oxygen in pipes:
NH3 + O2 + NO -> N2 + H2O
NH3 + NO2 + O2 -> N2 + H2O
NH3 + NO -> N2 + H2O

Question 44

TWC

Answer 44

Pt/Rh/CeO2/Al2O3 formulation, operates at stoichiometric air to fuel ration at approx 14.5% almost complete conversion
Oxidation:
NO + CO -> N2 + CO2
NO + HC -> N2 + H2O
HC + O2 -> CO2 + H2O
CO + O2 -> CO2
NOx conversion drops as A/F increases leading to no HC or CO coming in.

Question 45

NOx storage-reduction catalyst system

Answer 45

Used in Japan where fuel used doesn’t contain sulfur. Includes an adsorbent (BaO/Al2O3) to store NOx under lean operation, and a catalyst e.g Pt/Al2O3 to reduce NOx under normal stoichiometric conditions. With this system, a cyclic engine operation is required, that is controlled by the engine computer system. Major problems: - deactivation by sulfur present in the exhausts, catalyst deactivation due to the particle growth of both the precious metals and the NOx storage material