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Pollution control
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Important reminders:
Presentation on Honors course 3 & 4 October @ 13:15 in Science Centre, Westville Campus
!!!!!!! Hons. Applications close 31 October for admission in 2008!!!!!
Download Biol347 PowerPoint presentations:
http://marinesci.ukzn.ac.za/documents/
and choose the BIOL347 folder
REMEMBER: Each week’s presentations will only be available after the Tuesday lecture.
Presentation only provide the framework, please do some extra reading on each subject – you are expected to do 68 hours of self-study during the
course of the semester, i.e. about 5 hours per week
The Environment and People
Overview of Environmental science
Human Population growth
The Environment Live on Earth
The Biosphere: Populations, Communities, Ecosystems and
Biogeochemical cycles
The distribution of Live on Earth
The dynamic earth and Natural Hazards
Resource use and management
People and natural resources
Fundamentals of energy, fossil fuels, nuclear energy
Renewable and alternative energy sources
Water resources
Conserving Biological Resources
Land Resources and management
Food and Soil Resources
Dealing with Environmental Degradation
Principles of Pollution control, Toxicology and Risk
Water Pollution
Air Pollution: Local and Regional
Air Pollution: Destruction of the Ozone layer and global climate
change
Municipal Solid Waste and Hazardous WasteSocial Solutions to
Environmental Concerns
Environmental Economics
Historical and Cultural Aspects of Environmental Concerns
Principles of Pollution Control
Pollution and waste are symptoms, not causes, of the environmental crisis.
Paul Hawken
Pictures © 2006 Jones and Bartlett Publishers
Chapter objectives
• What is meant by “pollution”
• How pollution is produced
• How pollution is controlled
What is pollution?
Pollution = society’s excess output into the environment
Something produced in amounts high enough to be harmful to us, other life, or valuable objects
Pollution has many faces
Pollution as matter cycling and energy flow
The environment ultimately consists of matter cycles and energy flows.
Pollution represents local concentrations in the matter cycle or energy flows
e.g. Heat pollution is a form of air and water pollution
Pollution has many faces
Pollution as an accelerated natural process
Not only man-made, e.g. Volcanoes release gasses that is harmful to life, affect global climate and cause acid rain.
People cause pollution at a greater rate than nature, because:•High quantities of waste produced•Quality of waste accelerates pollution because of lots of new substances e.g. dye
Pollution has many faces
Pollution as a stepwise process
High volumes of waste produced as by products for other products/ processes
“Everything must go somewhere” as either energy flowing or matter cycling
As a result, waste often end up in water, air or land.
Life Cycle Analysis (LCA) / Cradle to grave analysis can pinpoint steps in processes that can either be eliminated or made more efficient
Therefore: “Cradle to grave” pollution = the many ways a product can pollute in its lifetime
Pictures © 2006 Jones and Bartlett Publishers
Pollution has many faces
Pollution as a stepwise process
Pictures © 2006 Jones and Bartlett Publishers
Pollution has many faces
Pollution = population x consumption
The amount of pollution depends on:
(1)The number of people(2)The amount of waste produced per person (determined by
consumption)
Therefore:
Pollution = population x consumption
OR
Pollution = population x consumption
OR
Pollution = population x consumption
History of pollution
Pollution exists from the beginning of time!!!
• Ancient volcanoes helped form the atmosphere
• Later on gasses from erupting volcanoes caused mass
extinctions
• Animals pollute rivers with urine and feces
• Bird droppings can contaminate areas surrounding nests
• Early civilizations discarded their waste (evidence in caves)
• Egyptians and Greeks had polluted drinking water Today, the scale of pollution is much greater due to:
• Large human population
• Fossil fuel-driven technologies
Controlling pollution
No water is pure in nature:
• Before people existed, water contained gasses and other
substances
• Highly polluted water only contain 1 % toxins and other
pollutants
• Raw sewage entering treatment facilities contained at least
99.9 % water. The problem: sewage and toxicant
molecules are much larger than water molecules
Zero pollution is an unrealistic goal:
• Modern society cannot exist without producing pollutants
• Total purity is economically impossible – the cost of
removing all pollutants increases exponentially after a
given point
• Total purity is unnecessary – the benefits of pollutant
removal decrease exponentially after a given point
• Not even nature is totally pure
Controlling pollution
How much to control?
Pictures © 2006 Jones and Bartlett Publishers
Controlling pollution
What to control?
Pictures © 2006 Jones and Bartlett Publishers
Low cost High cost
Controlling pollution
Pollution control vs. remediation vs. restoration
Remediation counteracts some of the effects of pollution after it has been released into the environment, e.g. treat lakes contaminated with acid rain with lime. Very expensive
Restoration seeks to reinstate the environment to its former condition. Extremely expensive
Pollution control aims to remove the pollutant and dispose of it in a landfill or incinerator, e.g. cleaning up toxic fly ash from electricity generating plants. Very expensive.
Controlling pollution
Implementing pollution control
There are three basic ways prevent people from polluting:
Persuasion: Ask people to change polluting behavior. Should be accompanied by education. Very cheap, but not too effective.
Regulation: Pass laws requiring less pollution. Most useful when polluters are few in numbers and pollution can be easily monitored, e.g. hazardous waste of large factories.
Incentives: Reward behavior that reduces pollution, e.g. tax incentives and subsidies for renewable energy use. Much lower cost than regulation. Examples: (1) deposits paid when potential waste is purchased and (2) pay as you throw schemes, where the polluter has to pay for discarding waste
Controlling pollution
Implementing pollution control
There are three basic ways prevent people from polluting:
Persuasion: Ask people to change polluting behavior. Should be accompanied by education. Very cheap, but not too effective.
Regulation: Pass laws requiring less pollution. Most useful when polluters are few in numbers and pollution can be easily monitored, e.g. hazardous waste of large factories.
Incentives: Reward behavior that reduces pollution, e.g. tax incentives and subsidies for renewable energy use. Much lower cost than regulation. Examples: (1) deposits paid when potential waste is purchased and (2) pay as you throw schemes, where the polluter has to pay for discarding waste