Lecture Presentations onEnvironmental Engineering

Course EENV101Part 1b Wk 3-4 (Jan 21- Jan 28)

Environmental RisksChapter Six of Textbook

By Engr. Jessica. M. Castillo

Rev. 3T 2015-16

Week 3 : Learning Objectives

Discuss how the different areas of the

environment (air, water and soil) are damaged

or destroyed. (CO2)

Identify the different Scenario in the

environment and its effects.(CO2)

Discuss the meaning of green chemistry, the

toxic release inventory and the pollution

prevention hierarchy. (CO2)

Explain how pollutants of the different

environments are produced. (CO2)

Explain the effects of pollutants on the

different environments. (CO2)Rev. 3T 2015-16

Rev. 3T 2015-16

Rev. 3T 2015-16

Threats to Biosphere• OVERUSE OF RESOURCES (FOOD etc.)

• DISRUPTION OF THE BIOGEOCHEMICAL CYCLE

• POLLUTION IN AIR WATER AND SOIL

• NATURAL ATMOSPHERIC CHANGES

• DISTURBANCE/IMBALANCE OF THE

ECOSYSTEM

Threats to Biodiversity

• OVERHARVEST

• HABITAT DESTRUCTION

• NEW SPECIES INTRODUCTION (includes GMO)

• POLLUTANTS INTRODUCTION

• GLOBAL ATMOSPHERIC CHANGES

Environmental Risk

Rev. 3T 2015-16

• Environmental Risk is the measure of the impact

resulting from exposure to an environmental hazard

(unsafe condition).

Example of environmental hazards:

Chemicals

Biological Pathogens

Ozone depletion

Water scarcity

Food shortage etc.

Risk = f (hazard, exposure)

• Note: Since hazard may not be completely

eliminated we can reduce also the risk by reducing

the exposure.

Rev. 1T 2013-14

Types of Environmental

Hazards

• Ecotoxicity : environmental risk applied to the

health of plants, animals, and the entire ecosystem,

which support human life.

Physical

Toxicological

Global hazards

Rev. 3T 2015-16

Rev. 1T 2013-14

Green Chemistry

• In green Chemistry, RISK is reduced

by using chemicals and materials that

would not pollute the environment or

or harm humans (living things) if they

are exposed to them.

• Green chemistry

reduces toxicity,

minimizes waste,

saves energy,

cuts down depletion of natural

resources

Rev. 3T 2015-16

• Examples of Green Chemistry

Initiatives:

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Taking chromium and arsenic, which are

toxic out of pressure-treated wood.

Using less toxic chemicals for bleaching

paper.

Substituting yttrium for lead in auto paint

Using enzymes instead of a strong base

for the treatment of cotton fibers.

Etc.

Hazardous wastes and

Chemicals

Effects of Exposure to toxic or hazardous chemicals

Death

Diseases like cancer

Birth defects

Infertility

Stunted growth

Neurological disorder

etc

Rev. 3T 2015-16

Toxic Release Inventory (TRI)

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The Toxic Release Inventory or TRI, is a

database that contains specific

toxic chemical release, transfer, waste

management and pollution prevention activities

from manufacturing facilities throughout the United

States.

www.epa.ohio.gov/portals/27/tri/tri/right2kn.pdf

Toxicitydeals with the effects of chemicals on living organisms

Bioaccumulation

Concentration of a chemical builds up in an organism

over time.

POLLUTION?

the introduction into the environment

of a substance or thing that has harmful

or poisonous effects.

Rev. 1T 2013-14

Disciplines in

Environmental Engineering

Pollution Control

Water and Wastewater management

Solid waste management

Toxic and hazardous waste management

Environmental Management

Pollution

Air

Water

Land/Soil

Noise pollution

Thermal pollution

Radiation pollution

Pollution is the introduction of contaminants

into the natural environment that cause adverse

change (in its composition and use).(Merriam-Webster Dictionary)

Contaminants

• Contaminants : unnatural presence of particles, substances such as poison or hazardous material

• …not naturally-occurring

• Man-made (anthropogenic)

• …changes in the natural environment

• Impairs the environment in performing its intended task

• Leads to the destruction of the ability of the environment to perform its intended function in the future.

Pollution Prevention Hierarchy

Rev. 3T 2015-16

Source Reduction

Recycling/Reuse

Treatment

Disposal

Example

The non-renewable resources have to be conserved as they cannot be replenished. The reserves of the resources such as fossil fuels are limited and man is heavily dependent on these resources for his day to day needs.

The renewable resources too have to be judiciously used. Though they are replenished, they are subjected to a lot of pollution that renders them useless. E.g. water

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RISK ASSESSMENT

Hazard Assessment

Dose-Response Assessment

Exposure Assessment

Risk Characterization.

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Hazard Assessment

Dose-Response Assessment

“ What health problems are caused

by the pollutant when released

into the environment?”

What is the probability that humans (living things)

will experience an adverse effect when exposed

to a specific concentration of a chemical

(pollutant)?”

Exposure Assessment

Risk characterization

“ How severe will the adverse response

(effect) be based on the extent and

frequency of exposure?”

Based on the hazard and the exposure,

what is the level of the risk?

What is the acceptable level of risk?

Rev. 1T 2013-14

12 Principles of Green Engineering

Developed by Paul Anastas and Julie Zimmerman

1. Inherent Rather Than Circumstantial Designers need to strive to ensure that all materials and energy

inputs and outputs are as inherently nonhazardous as possible.

2. Prevention Instead of Treatment It is better to prevent waste than to treat or clean up waste after it is

formed.

3. Design for Separation Separation and purification operations should be designed to minimize energy

consumption and materials use.

4. Maximize Efficiency Products, processes, and systems should be designed to maximize mass, energy,

space, and time efficiency.

5. Output-Pulled Versus Input-Pushed Products, processes, and systems should be "output pulled" rather

than "input pushed" through the use of energy and materials.

6. Conserve Complexity Embedded entropy and complexity must be viewed as an investment when making

design choices on recycle, reuse, or beneficial disposition.

7. Durability Rather Than Immortality Targeted durability, not immortality, should be a design goal.

8. Meet Need, Minimize Excess Design for unnecessary capacity or capability (e.g., "one size fits all")

solutions should be considered a design flaw.

9. Minimize Material Diversity Material diversity in multicomponent products should be minimized to

promote disassembly and value retention.

10. Integrate Material and Energy Flows Design of products, processes, and systems must include

integration and interconnectivity with available energy and materials flows.

11. Design for Commercial "Afterlife“ Products, processes, and systems should be designed for

performance in a commercial "afterlife."

12. Renewable Rather Than Depleting Material and energy inputs should be renewable rather than

depleting.

Rev. 1T 2013-14

a) R.A. 9275 Philippine Clean Water Act of 2004b) R.A. 8749 Philippine Clean Air Act of 1999c) R.A. 9003, Ecological Solid Waste

Management Act of the 2000d) R.A. 6969, Toxic Substances and Hazardous

and Nuclear Wastes Control Act of 1990

Government Lawsto protect the environment and prevent pollution