BUILDING UTILITIES 1 LECTURE 2.pdf

11/22/2012

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM WATER

BUILDING UTILITIES 1 LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYTEM Prepared by: Arch./En.P. Rachelle S. Santos

- a combination of two elementary substances – hydrogen and oxygen. It appears in its natural state as: Liquid – 830 times heavier than air Solid – ice Gas – Vapor or steam/133 times lighter than air -We tend to think of water as an inexhaustible natural resource. However, our supply of fresh water is definitely limited, and improved conservation practices are necessary if our needs are to be supplied.

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM THE DEMAND OF WATER

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM THE DEMAND OF WATER

DEMAND

REQUIREMENT

Drinking, Cooking, Dishwashing

Must be pure, sterilized and protected from contamination. Supplies taken direct from mains or from exclusive storage.

Personal Washing and Domestic Cleaning

Similar but moderated to allow cold and hot supplies to be drawn from main storage tank or cistern via distribution network.

Laundry

Generally clean and wholesome, soft and free form Iron and Manganese staining.

Fire Fighting

High Pressure. Connections must not permit contamination of mains water.

DEMAND

REQUIREMENT

Swimming

Clean, filtered and sterilized with free chlorine residue for post-sterilization. Can be recirculated.

Boilers and Heating Plants

Soft treated water, stored and circulated separate from domestic supplies.

Irrigation

No special requirement, except reasonably free from solids and slit (result in blocked Pipes and nozzles) and uudecomposed material (pollution).

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM SOURCE

THE WATER CYCLE Rain Water

SOURCES OF WATER COLLECTION ADVANTAGES

Collected from roofs of buildings and special water sheds and stored in cisterns or ponds

DISADVANTAGES Only a source during Water is soft and pure the wet season; and is suitable for the Storage becomes a hot water supply breeding place for system mosquitoes

Cistern water for drinking should be boiled, chlorinated or otherwise sterilized

Natural Surface Water

Obtained from ponds, lakes and rivers

Roofs may not be clean Easy to acquire Usually in large quantities Used for irrigation, industrial purposes and when treated, for community water supply

Contains a large amount of bacteria, organic and inorganic substances; purification and treatment is necessary

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11/22/2012

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM

SOURCES OF WATER SOURCE

Ground Water

COLLECTION

ADVANTAGES

Water Quality Problems and their Corrections DISADVANTAGES

Obtained from underground by means Usually has an of mechanical and abundant supply manual equipment

May have organic matters and chemical elements; treatment is suggested

From springs and wells and is the principal source of water for domestic use in most rural areas

Character of ground water, its hardness, depends upon the nature and condition of the soil and rock through which it passes or percolates

Requires less treatment because of natural filtering

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM

PROBLEM

Acidity

CAUSE

Entrance of oxygen and carbon dioxide

EFFECTS

CORRECTION

Raising alkaline content by the introduction of a neutralizer (sodium Rusting and clogging of silicate) steel pipes Corrosion of nonferrous pipes

Clogging of pipes

Hardness

Boiling

Presence of magnesium and calcium salts Impaired laundry and cooking

Use an ion exchanger (zeolite process)

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM

Water Quality Problems and their Corrections OBJECTIONABLE ELEMENT PROBLEM

Turbidity

CAUSE

Stilt or mud in surface or in ground

EFFECTS

METHOD OF TREATMENT

CORRECTION Carbon Dioxide, Hydrogen Sulfide

Aeration

Suspended Material

Coagulation and Settling processes

Bacteria

Chemicals and Sand Filtration

Calcium, Magnesium

Addition of Water Softeners

Discoloration Filtration Bad taste

Color

Presence of iron and manganese

Pollution

Contamination by organic matter or sewage

Discoloration of fixtures and laundry

Disease

Oxidizing filter

Chlorination

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM WATER PURIFICATION METHODS 1. Aeration – spraying the water into the atmosphere through jets or passing it over rough surfaces to remove entrained noxious gases such as carbon dioxide or hydrogen sulfide. 2. Coagulation and Precipitation – addition of coagulants, such as ferrous sulfate and lime, to the water which cause the larger suspended particles to form a gelatinous mass which precipitates readily. The precipitate is gathered in large dumps and disposed of. 3. Filtration – water is passed through layers of sand and gravel in concrete basins in order to remove the finer suspended particles. Special elements are sometimes added to remove particular objectionable elements.

Iron

Iron Filters

Sulfur

Chlorination

Pathogenic Germs

Disinfection

Acid

Marble or Limestone Filtration

LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM WATER PURIFICATION METHODS 4. Sedimentation – “the settling process”, where water is left in a large basin for a long period of time. The sediments denser than water sink to the ground while those lighter float to the surface. The sediment-less water at the center of the basin is then removed. 5. Chlorination – water is injected with hypo-chlorite or chlorine gas to kill the harmful bacteria

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