PUBLIC HEALTH ENGINEERING (CE-355)

Saadat Ali

Phone: 0333-2386630

Email: saadatali18@yahoo.com

Course Introduction Water demand, sources, quality, sampling, analysis,

treatment, distribution network design

Wastewater generation, quality, effects on

environment and health, treatment

Solid waste management

Air and noise pollution control

Environmental Impact Assessments & Environmental

legislations

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Course Objectives

To give students basic concepts about public

health engineering

To give you idea about mitigation of environmental

issues that affect the public health

To make you aware about health and

environmental issues related with civil engineering

To make you aware about present environmental

status of the country and the work going on

To make you aware about legislations

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Recommended Books and Materials

Text Book: Water Supply and Sewerage. By

E.W. Steel, 6th edition.

Reference Book:

All lectures handouts will cover all the topics.

If out of books, reading material would be

provided to students as hard copy.

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Marks Distribution

2 OHTs = 30 (2 x 15)

1 final exam = 30

4 assignments = 10

4 quizzes = 10

Term project = 20 (10 write up + 10 presentation)

Total = 100

Practical

Viva voce= 20

10 Assignments = 50

2 quizzes = 10

Field visit = 20 (10 visits + 10 reports)

Total = 100

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Introduction to Public Health

Engineering

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The Concept

Many diseases are preventable through simple, non-medical methods

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Public Health?

the science of preventing disease, prolonging life and promoting health through the organized efforts of

society, communities and individuals

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History of Public Health From the beginnings of human civilization, it was

recognized that polluted water and lack of proper waste

disposal spread communicable diseases (Moin-ja-darro

and Harrapa civilizations)

Roman times, it was well understood that proper

diversion of human waste was necessary for public

health in urban areas.

During the 14th century Black Death in Europe, it was

believed that removing bodies of the dead would

further prevent the spread of the bacterial infection.

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The Water Water covers 70.9% of the Earth's surface, and is vital for all

known forms of life.

Oceans hold 96.5% of surface water, glaciers and polar ice caps

2.4%, and other land surface water such as rivers, lakes and

ponds 0.6%

Approximately 70% of the fresh water which is actively handled by

humans, is consumed by agriculture.

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The Water

Clean drinking water is essential to humans and

other life forms.

Scientists have estimated that by 2025

more than half of the world population will be

facing water-based vulnerability

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Water Cycle

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The water cycle dynamics does the trick 13

but, H2O is always on the move ...

Instant snap shot:

Ice caps

2.7%

Rivers

0.0002% Lakes

0.007%

Oceans

96.5%

Clouds

0.001%

Groundwater

0.7%

Shortage of freshwater !

A dynamic perspective

gives a better description:

4 600 years 3 000 years

8 days

16 000

years 280

days

Renewable rain gives in 2000 years as

much water as is in the oceans!!!

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Water Chemistry

Water appears in nature in all three common states of matter,

As vapor in clouds;

As solid in glaciers and

As liquid in aquifers in the ground.

Water has high specific heat capacity of 4200 J/(kgK) due to hydrogen bonding between its molecules.

The maximum density of water occurs at 3.98 C (39.16 F).

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This property allows water to moderate Earth's

climate by buffering large fluctuations in temperature.

It has the anomalous property of becoming less dense,

when it is cooled down to its solid form. Ice expands to

occupy 9% greater volume and floats over water.

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Water is miscible with many liquids, such as ethanol, in all proportions, forming a single homogeneous liquid. On the other hand, water and most oils are immiscible usually forming layers according to increasing density from the top.

Water is a universal solvent. Substances that dissolve in water, e.g., salts, sugars, acids, alkalis, gases are known as hydrophilic (water-loving) substances, while those that do not mix well with water (e.g., fats and oils), are known as hydrophobic (water-fearing) substances.

The boiling point of water is dependent on the barometric pressure. On the top of Mt. Everest water boils at 68 C (154 F), compared to 100 C (212 F) at sea level. Conversely, water deep in the ocean near geothermal vents can reach temperatures of hundreds of degrees and remain liquid.

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Water and Human Human body contains from

55% to 78% water. Most

scientists agree that

approximately 2 liters (6 to 7

glasses) of water daily is the

minimum to maintain proper

hydration.

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Potable Water

Water fit for human consumption is called drinking water or

potable water.

Some five million deaths a year are caused by polluted drinking

water. The World Health Organization (WHO) estimates that

safe water could prevent 1.4 million child deaths from diarrhea

each year

It takes around 3,000 liters of water, converted from liquid to

vapour, to produce enough food to satisfy one person's daily

dietary need

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Water Scarcity

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Pakistan available water = 1200 m3/c/year

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Sanitation

Sanitation is the hygienic means of promoting health

through prevention of human contact with the hazards of

wastes. Hazards can be either physical, microbiological,

biological or chemical agents of disease.

These includes human and animal feces, solid wastes,

domestic wastewater (sewage, sullage, greywater),

industrial wastes and agricultural wastes

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Sanitation the silent crises

2.4 billion people (40% of the world's population) lack so called adequate sanitation

18% of the world's population lack safe water supply

10% of all wastewater in developing countries is treated

Malnutrition is a major factor making us more vulnerable to disease and death, thus food security is important

The combined effects of poor personal and domestic

hygiene and lack of safe water and good environmental

sanitation is considered the most important risk factor

for disease and death

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What sanitation is about

Personal and household hygiene

Clean environment incl. water

Solid waste management

Greywater disposal and treatment

Safe excreta disposal

Stormwater handling

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Traditional interpretation:

Additional perspectives:

Acceptance, affordable, convenience and pride

Environmentally sustainable arrangements

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Principle:

Organic other solid waste

Stormwater sewage

Industrial household wastewater

Black toilet water greywater

Strategies for sanitation improvements

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Why do we often act as if we were

only a few hundred million people on

earth?

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v

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What is Wastewater Reuse?

Terminology

Water reuse

The beneficial use of treated wastewater for agriculture, industry, etc.

Water reclamation

Reclamation involves all processes used to treat wastewater so that it can be beneficially reused

Water recycling

Recycling generally means reuse of wastewater back in the same cycle where it is generated.

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What is Wastewater Reuse?

Categories of Water Reuse

Indirect Reuse

Reuse of wastewater within the context of natural water systems (rivers, aquifers, etc.). The ultimate indirect reuse is through the global hydrologic cycle

Other terms: Indirect potable reuse

Direct Reuse

The direct beneficial reuse of treated wastewater for agriculture, industry, etc.

Direct potable reuse: the reuse of reclaimed water for potable uses

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Driving Factors for Water Reuse

Water Availability

Water Consumption

Water Quality

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Benefits of Water Reuse

Important element of integrated water resources utilization and management

Treated effluent is used as a water resource for many possible beneficial purposes

Pollution control e.g. for many Arab coastal cities, wastewater would not be discharged to the sea thus reducing pollution to the marine environment and not creating public health issues

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Public Health and Water Quality

Considerations

Physical water quality considerations

Turbidity, color, etc.

Chemical water quality considerations

Chemical constituents including solids, metals, nitrogen,

phosphorus, etc.

Biological water quality considerations

Pathogens including bacteria, helminths, virus, etc.

Emerging water quality considerations

Pharmaceuticals, hormonal products, personal care

products

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Water Reuse Design Criteria

Water quality requirements

Monitoring requirements

Treatment process requirements

Treatment reliability requirements

Operational requirements

Cross-connection control provisions

Use area controls

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Treatment Reliability

Standby power supply

Multiple or standby unit processes

Emergency storage/disposal provisions

Provisions for continuous disinfection

Non-design features

Qualified personnel

Monitoring

O & M program

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Solid Waste

Waste: Anything which is not useful for a person is called as waste.

However waste is a relative terminology and a useless thing for a person-could be useful for others, e.g. Scavengers collect the solid waste from streets and sell it to waste buyers and earn money.

Solid Waste (SW): Solid waste is the waste arising from all human and animal activities and is normally solid, semi solid or liquid discarded as unwanted material.

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Problems in SWM

The problems associated with the management of solid waste in Pakistan are due to the quantity and diverse nature of waste.

The development of extensive urban areas

The engineering limitations of the impacts of technology, energy and raw materials

So, to achieve a goal of proper solid waste management in an efficient and orderly manner, the fundamental aspects and relationships involved must be identified and understood early.

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Present status in Pakistan It is estimated that presently, 56,000 tons per day of

solid waste is generated in Pakistan.

No weighing facilities are installed at any disposal sites

Open burning of waste or open disposal

Collection 51-69 %

No Disposal facilities

A lot of potential for recycling and involvement of private sector which is overlooked

Hazardous hospital and industrial wastes are being simply treated as ordinary waste

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Air and Noise

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Danger in the air we breathe At rest, human beings breathe in and out at every 4 seconds,

16 times in a minuteand

960 times an hour or

8.5 million times of air intake in a year.

This adds up to I million gallons a year (4 million liters) of oxygen-related air in a year

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Natural sources of air pollution

Ash and smoke from lightning-triggered forest fires

Ash and dust from volcanic eruptions

Salt spray from sea waves

Methane from decaying organic matter

Pollen from plants

Dust from windstorms

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Air Pollution: regional & global problems

Acid rain

Photochemical Smog

Industrial Smog

Greenhouse effect and global warming

Depletion of stratospheric ozone

Eutrophication

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Common health effects of air

indoor pollution

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We never know the worth of water till the well is

dry. ~Thomas Fuller,

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