Module 1 - Water & Human Needs

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WATER and theHUMAN NEEDS

Danilo V. Ravina, NAMPAP - Cebu


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What is the nature of water?

WATER is: H2O. A liquid without color, taste, or odor.

Water begins to freeze at 0 degrees centigrade and boils at 100 degreescentigrade.

When liquid, it is virtually incompressible.

Most of the worlds water is in the sea; less than 1% is fresh water.

Water makes up 70% of the earths surface & occurs as standing water(oceans, lakes) and ru nni ng water (rivers, streams), rain, and vapor.

Water makes up 60-70% of the human body or about 40 liters,distributed as follows:

- 25 liters inside the cells

- 12 liters in tissue fluid

- 3 liters in blood plasma

source: The Hutchinson Concise Dictionary of Science



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What is the Earths water resource? Bodies of water (oceans and seas) - 70% of the earths

surface

Distributed as follows:

1. Salt water 67%

2. Fresh water 3%, where it is divided as:

2a. Frozen in the polar ice caps 2%

2b. Global water source 1%


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What is the importance of water? Water its supply, usage and recovery, often defines civilization since

the basic needs of humans are derived from it.

If the human body loses 4 liters of water, it will experiencehallucinations. A loss of 8 to 10 liters may cause death.

About 1.5 liters a day are lost through breathing, perspiration andfeces.

The additional amount lost in urine is the amount needed to keep thebalance between input and output.

A person cannot survive more than 5 to 6 days without water or 2 to 3days in a hot environment.

Source: The Hutchinson Concise Dictionary of Science



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What are the basic human needs forwater?

Nourishment - for drinking and cooking

Cleaning & Hygiene - for bathing and laundry Livelihood use - for example: farming

Protective use - for fire fighting

Ornamental use - for example: landscaping

Ceremonial use - for example: religious rites



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What is WATER QUANTITY? Water Quantity is the amount of water available to meet desired needs.

They are as follows:

1. Nourishment: Drinking 11 liters/person/day

2. Cleaning & Hygiene :

Bathing / Personal Hygiene - 80 liters/person/day

Laundry - 53 liters/person/day

Dishwashing - 53 liters/person/day3. Livelihood: Office 57 liters/person/shift

Factory 57 to 132 liters/person/shift

4. Protective Use: Fire Protection 1,892 liter/minute (minimum)

as per Fire Code of the Phil.

Wet Standpipe 190 liter/minute @ 2 kg/sq.cm.as per NBC 2005 Revised

5. Ornamental Use: Lawn sprinkler 0.32 liter/second (5 gpm)



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What is Water Quality?

Water Quality is the degree to which water is pure

enough to fulfill the requirements of various demands oruses.

Water Demand Water Quality Requirements

1. Nourishment Pure, sterilized & protected from

contamination2. Cleaning & Hygiene Clean, wholesome & with

provision for hot & cold soft

water

3. Protective use High pressure

4. Ornamental use Free from silt

5. Ceremonial use Clean & wholesome



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What are the characteristics used as

the basis of water quality? For use in a building, the water supply must meet a

minimum level of quality or maximum permissible level

based on the following:

1. Physical Characteristics

a. Turbidity

b. Color

c. Taste

d. Odor

d. Temperature

NATIONAL WATER RESOURCES COUNCIL



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2. Chemical Characteristics

a. Hardness

b. Alkalinity and Acidity

c. Carbon Dioxide

d. Dissolved Oxygen

e. Organic Nitrogen

f. Chemical Oxygen Demand (COD)

g. Iron & Manganese

h. Toxic substancesi. Phenolic compounds

NATIONAL WATER RESOURCES COUNCIL


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3. Biological & Radiological Characteristics

a. Presence of Coliform bacteria

b. Presence of Pathogenic bacteriac. Presence of radioactive materials


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What are some of the Water Quality

Problems & their Causes, Effects &Correction?

Problem: Turbidity the degree of cloudiness or

muddiness of water. Cause: Silt or suspended matters picked up in the surface

or surface flow.

Effect: Discoloration and bad taste. Has little detrimental

effects on health.

Correction: Filtration


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Problem: Color can be measured through visual

comparison of the sample to the distilled water

Cause: Presence of Iron and Magnesium. Has little

detrimental effects on health.

Effect: Discoloration of fixtures and laundry

Correction: Precipitation by filtration through oxidizing

filter.


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Problem: Taste Pure water is tasteless.

Cause: Presence of algae, decomposing organic matter,

dissolved gases & phenolic substances.

Effect: Bad taste

Correction: Water treatment process


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Problem: Odor Pure water is odorless. Odor should be

absent or very faint for water to beacceptable for drinking.

Cause: Existence of contaminants in the water.

Effect: Bad odor

Correction: Water treatment process


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Problem: Hardness of Water

Cause: Presence of Calcium and Magnesium carbonates& bicarbonates. Presence of Calcium andMagnesium sulfate & chloride.

Effect: Clogging of pipes. Impaired laundering & foodpreparation (increases soap consumption as

lathering is more difficult). Causes scaling,resulting in the reduction of thermal efficiency &restriction of flow. Magnesium & Calcium sulfatehas a laxative effect.

Correction: By boiling(for carbonate hardness). By

chemical precipitation using lime & sodiumcarbonate (for sulfate & chloride hardness.Use ofwater softeners (example: zeolite)


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Problem: Pollution

Cause: Contamination by organic matter or sewage

(pathogenic bacteria)

Effect: Disease

Correction: Chlorination


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What are the other terms used to describe

Water Quality?

Fresh Water is water having a salt concentration below0.01%.

Salt Water contains at least 3% salt (30 parts salt per1000 parts water).

Brackish Water is a mixture of fresh and salt water,typically found where rivers enter the ocean.

Soft Water is relatively free of minerals that cause soapto precipitate causing scale buildup.

Polluted Water contains one or more impurities that

make the water unsuitable for a desired use. Purified Water the pollutants are removed, rendering

the water harmless.


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Black Water is water drained from toilet bowls and

urinals; carries body wastes and majorpollutants.

Gray Water is water drained from lavatories, sinks,

laundry trays and showers; contains minor

pollutants. Storm Water is rainwater drained from gutters and

downspouts.


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What is the Hydrologic Cycle? Hydrologic cycle, also commonly known as water cycle,

consists of evaporation, condensation and precipitation.

There are 3 principal loops in the cycle, namely:

a. Surface Runoff Loop

b. Evapotranspiration Loop

c. Groundwater Loop


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What is the relationship between Humans

and Water Cycle?

Any fresh water that is used must come out of the cycle at

one point or another.

Likewise, all the polluted wastewater we put down the

drain or throw out goes back into the cycle.

Anything we do to the land surface, from development todeforestation, will influence the infiltration-runoff ratio

and thus the cycle.

Anything we put into the air may end up as a contaminant

in precipitation. Any chemicals we put on or bury in the soil are subject to

leaching into the groundwater.


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What is the science of water? The science of water is known as Hydraulics.

Hydraulics is a field of study concerned with utilizing theproperties of water, in particular the way they flow and

transmit pressure, and with the application of theseproperties in plumbing engineering.

Hydraulics is categorized as to:

a. Hydrostatics is the science of water at rest.

b. Hydrokinetics is the science of water in motion.

c. Hydrodynamics is a general term associated with thescience of the force exerted by water in motion.


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What are the General Properties of Water?

Water supply in buildings is usually delivered from avariety of sources which are often pumped or proceed bygravity to the point of use. This means that theconveyance of water are through pipes exhibit certainbehavior of the Laws of Physics.

These general physical properties of water include:a. Water Level

b. Mass

c. Force

d. Pressuree. Head

f. Capillarity


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Water Level: Water always takes the shape of its

container to the limit of its volume and tends to find itsown level.

Mass: Mass is the amount of matter in a body. It remainsconstant regardless of where the body is in the universe.For water, a volume of one liter at a temperature of 4

degrees centigrade has a mass of one kilogram andmaybe contained in 1 cubic decimeter.

Force: Force is that which changes the state of rest or theuniform motion of a body. The equation of force is:

F or ce = M ass x A cceler ation. In other words, when a

mass of 1kg is under the standard acceleration of9.81m/sec/sec, a gravitational force of 9.81 newtons isacting on it.


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Pressure: Pressure is defined as the force per unit area.

In the case of water, the following characteristics can beobserved:

a. Pressure exerted in water is transmitted equally in alldirections.

b. The pressure at any point in a quantity of waterdepends on the vertical depth of the point below the freesurface of the water but does not depend upon the shape or

size of the container. Thus, the relationship betweenpressure and depth is one ofdirect proportion, meaning,that at twice the depth the pressure is twice as great.

c. Water is practically incompressible.

d. Pressure applied anywhere to a body of confined orenclosed fluid is transmitted with undiminished force inevery direction.


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Head: Head in water is measured vertically from the

free surface of the liquid to the point at which pressure is

being calculated. A head of water of 1.00 meter produces

a pressure on its base of 9810 Newtons/sq.meter or

9.81 kPa. It should be noted that head is the only factor

that decides intensity of pressure, not the volume of water

in the pipe.

Capillarity: Commonly known as capillary attraction, is

the spontaneous movement of water up or down narrow

tubes and pipes due to the unbalanced molecular attraction

at the boundary between the water and the pipe.


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What are the common Hydraulics Data of

Water? The units of measure or hydraulics data frequently used to

describe properties relating to water are as follows:

1 cubic meter of water = 1000 liters or 264 gallons

= 9.81 kilopascal (kPa)

Head of water in meters = pressure in kilopascal

3.785 liters of water = 1 gallon

1 liter/second (lps) = 15.85 gallons/minute (gpm)

1 pound/square inch = 6.90 kilopascal


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1 water supply fixture unit (wsfu)* = 1 to 1.5 gpm of

water flow rate*wsfu a numerical weighing factor to account for the

water demand of various plumbing fixtures, using the

privately installed lavatory as equal to 1 wsfu.

1 drainage fixture unit (dfu)* = 0.5 gpm of drainage

flow rate

*dfu a numerical weighing factor to account for the

sewage flow of various plumbing fixtures, using the

privately installed lavatory as equal to 1 dfu.


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References:

Doyle, K.M.: Plumbing and Gas Fitting, Volume 2,

Government Printing Office, Mulgrave St., Wellington,

1990

National Water Resources Council. Rural Water SupplyDesign Manual Volume 1, NWRC, Quezon City,

Philippines, 1980

Nebel, B.J. and Wright, R.T.: Environmental Science 4th

Edition, Prentice Hall, Inc., New Jersey, 1993


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Module 1 - Water & Human Needs

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