11/22/2012LECTURE 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 DEMAND Drinking, Cooking, Dishwashing REQUIREMENT Must be pure, sterilized and protected from contamination. Supplies taken direct from mains or from exclusive storage. Similar but moderated to allow cold and hot supplies to be drawn from main storage tank or cistern via distribution network. Generally clean and wholesome, soft and free form Iron and Manganese staining. High Pressure. Connections must not permit contamination of mains water. LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM THE DEMAND OF WATER DEMAND Swimming REQUIREMENT Clean, filtered and sterilized with free chlorine residue for post-sterilization. Can be recirculated. Soft treated water, stored and circulated separate from domestic supplies. No special requirement, except reasonably free from solids and slit (result in blocked Pipes and nozzles) and uudecomposed material (pollution). Personal Washing and Domestic Cleaning Boilers and Heating Plants Laundry Fire Fighting Irrigation LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM THE WATER CYCLE Rain Water LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM SOURCE SOURCES OF WATER COLLECTION ADVANTAGES Collected from roofs of buildings and special water sheds and stored in cisterns or ponds Cistern water for drinking should be boiled, chlorinated or otherwise sterilized 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 Roofs may not be clean Easy to acquire Usually in large quantities Used for irrigation, industrial purposes and when treated, for community water supply Natural Surface Water Obtained from ponds, lakes and rivers Contains a large amount of bacteria, organic and inorganic substances; purification and treatment is necessary 1 treatment is suggested LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM Water Quality Problems and their Corrections PROBLEM CAUSE EFFECTS Corrosion of nonferrous pipes CORRECTION Ground Water Obtained from underground by means Usually has an of mechanical and abundant supply manual equipment Acidity Entrance of oxygen and carbon dioxide Raising alkaline content by the introduction of a neutralizer (sodium Rusting and clogging of silicate) steel pipes Clogging of pipes Boiling From springs and wells and is the principal source of water for domestic use in most rural areas Requires less treatment because of natural filtering Character of ground water. 5. Sedimentation – “the settling process”. The sediments denser than water sink to the ground while those lighter float to the surface.11/22/2012 LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM SOURCES OF WATER SOURCE COLLECTION ADVANTAGES DISADVANTAGES May have organic matters and chemical elements. Chlorination – water is injected with hypo-chlorite or chlorine gas to kill the harmful bacteria 2 . Magnesium Iron Pollution Contamination by organic matter or sewage Disease Chlorination Sulfur Pathogenic Germs Acid Aeration Coagulation and Settling processes Chemicals and Sand Filtration Addition of Water Softeners Iron Filters Chlorination Disinfection Marble or Limestone Filtration LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM WATER PURIFICATION METHODS 1. 2. 3. The precipitate is gathered in large dumps and disposed of. Coagulation and Precipitation – addition of coagulants. The sediment-less water at the center of the basin is then removed. Special elements are sometimes added to remove particular objectionable elements. depends upon the nature and condition of the soil and rock through which it passes or percolates Hardness 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 PROBLEM CAUSE EFFECTS CORRECTION LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM OBJECTIONABLE ELEMENT METHOD OF TREATMENT Carbon Dioxide. 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. where water is left in a large basin for a long period of time. such as ferrous sulfate and lime. LECTURE 2: FUNDAMENTALS OF WATER SUPPLY SYSTEM WATER PURIFICATION METHODS 4. Filtration – water is passed through layers of sand and gravel in concrete basins in order to remove the finer suspended particles. to the water which cause the larger suspended particles to form a gelatinous mass which precipitates readily. its hardness. Hydrogen Sulfide Turbidity Stilt or mud in surface or in ground Discoloration Filtration Suspended Material Bad taste Bacteria Color Presence of iron and manganese Discoloration of fixtures and laundry Oxidizing filter Calcium.