The cooled water (chilled water) may be used for different applications as follows

• To cool electronic systems.
• To cool equipments and machines.
• To condition the air at individual rooms in a building as universities, hotels, hospitals etc..
• To cool systems inside turbines.
• To provide cooling at preservative area where animals and specimens are kept in ships and aircraft.

Definition of  Water Treatment Conditioning :

Water Treatment conditioning is the process by which hard water, both temporary and permanent, is made soft  ( by total reduction or reducing the proportion of chemicals causing hardness) to be suitable for use as boiler feed water. Conditioning is necessary for maximum output of steam and for protecting the life of boiler bodies, tubes and pipes by prevention of scale formation and corrosion.

Various water conditioning processes are employed: precipitation water treatment processes, ion exchange water treatment processes, demineralisation water treatment process , phosphate condition-ing, etc.

More than 50 per cent of water in chemical industries is used for cooling. Before setting up an industrial plant at any place, the water supply arrangement is first looked into. The available water is also analysed to find out the degree of hardness.

Besides cooling tower and boiler need water treatment processed  water is used as :

 Boiler Water Treatment Process

Water for raising steam in boilers must be soft and must not contain too much dissolved or suspended matter, so as to avoid the troubles of :

1. Scale formation
2. Corrosion  and
3. Foaming.

(a)  Scale formation: The water must be soft, otherwise, a deposit of mainly CaCO3 and CaSO4, is formed on the walls of the boiler. The formation of this hard heat insulating crust, called boiler scale, causes a much greater consumption of fuel and  also a rapid deterioration of the boiler due to overheating. The life of the boiler is thus gre.any shortened. Under the stress of continued overheating tne boiler may give way and burst due to unequal expansion of the body of the boiler and scale.

 (b) Corrosion:  Continuous deposition of scales on the walls of the boilers causes corrosion, that is the material of the body is ccrroeed and damaged. The boiler body thus gets weaker and may burst.

(c) Foaming:  Too much of dissolved matter in boiler water causes foaming and frcthing. This prevents the formation and escape of steam. Magnesium chloride if present in water, is readily hydrolysed giving NCI, which attacks the body of the boiler made of iron, causing pitting and corrosion. Pitted zones are the vulnerable points in boilers. The boiler water must not therefore contain MgCl2, i.e., it must be soft. Sea water, cannot be used in marine boilers, since it contains too much of MgCl2.

 Laundry water  Treatment Process

Water used for laundering purpose must be soft. When hard water is treated with soap, the latter is removed from water as an insoluble precipitate and is not therefore available for detergenation until all the calcium and magnesium salts are removed, that is, until the hard water is softened.

When hard water is treated with a soap solution, the soluble   sodium stearate (sodium stearate representing the soap) reacts with the calcium, magnesium and iron salts present in hard water to yield insoluble slimy precipitates of the stearates of the minerals. Soap is thus removed from water:

2C17H35COONa+Ca++    —–>  (C17H35COO)2Ca+Na+
Sodium stearate                                          (Soluble Soap)

Hard water will not, therefore, form a lather with soap until st ff. cient qbantity of it has been added to precipitate all the calcium, magnesium and iron in the water as insoluble stearate.

Laundry water must also be free from iron, otherwise brown Fe(CH)3 would be deposited en the fabric and stain the same.

When civilization developed human became aware of safe drinking water. From that time more water  filtration demand increasing gradually. Boiling water is very oldest water filtration process. This methods of water purify process killed bacteria and also this phenomena is called later as Disinfection.

Some Water Treatment Process
Reverse osmosis water treatment process
Deionized water treatment process
Electrodialysis water treatment process
Evaporation water treatment process
Distillation water treatment process
Softening water treatment process
Activated carbon filter process

Singaporean Government supplying city water from high technology of desalination by Reverse Osmosis water treatment process followed by UV and Ozone disinfection to all area in Singapore with high water quality, hygienic and  free micro organism  and  also challenging to private bottling water company for their water purity. They are supplying  water to domestic purpose for drinking purposes. This  water quality Total Dissolved Solids range is 70 – 90 ppm maintaining .

Industrial Sewage Water is  allowing to public main sewers lines or connecting to river or Sea. Before allowing these it should be acceptable by environment department as they having some Range parameters. so sewage water is essential  for certain waste water treatment to keep the world health organization WHO and local health department acceptable  range.

Each Factories having separate sewage treatment plant to remove excess unwanted contamination in sewage waters. So they have to allot some special wide area to install sewage treatment plants.

SCADA means supervisory control and data acquisition. SCADA mainly consider  to industrial equipment control systems like water treatment plant, waste water treatment plant, Boiler water treatment plant and sea water treatment process. This  computer systems monitor and control all operation as per programmed in PLC micro systems.  Waste Water Treatment system SCADA is mainly used such as wide area sewage treatment plant to monitoring all process within the control room and SCADA is reduce to water treatment engineers time to control and operate waste water treatment plant process.  Here in  Sewage Treatment, How SCADA controlling , monitoring  and collect data acquisition.

1. Primary Waste Water Treatment
2. Secondary Waste Water Treatment
3. Tertiary Waste Water Treatment

• Pre-chlorination dosing: This is made to disinfect the raw water from any infections.
• First filtration: By the pressure sand filters to remove turbidity and suspended solids.
• De-chlorination dosing: To remove the remaining Chlorine after the pressure sand filter.
• Antiscalent dosing is very important to prevent Calcium Sulfate form scaling.
• Acid dosing is very important to prevent calcium carbonate form scaling by  Sulfuric acid 98%.

• Second water filtration by cartridge filter (5micron) is important to remove any particles exceed 5 micron size.
• Feeding water into the membrane after boosting it to indicated pressure 16 bar for membrane input and the water treated to reduce the TDS under high pressure.
• The permeate water after reverse osmosis must go through another stage
• Adjusting PH value by Sodium hydroxide 49%
• Post chlorination dosing for disinfection by Sodium hypochlorite 12%.

Preliminary Treatment of Sewage Water Treatment process consists solely in separating the floating materials like dead animals, tree branches, paper, piece of rags, wood etc and also the heavy settle able inorganic solids. it also helps in removing the oils and greases etc from the sewage water.

This water treatment process reduces the BOD ( Biological oxygen demand ) of the waste water by about 15 to 30 %. This waste water treatment process used are Screening for removing floating papers, rags, clothes, etc. Grit champers or Detritus tank for removing grit and sand and skimming tanks for removing oils and grease.

• Filters ( intermittent sand filters as well as trickling filters

• Aeration Tanks with the feed of activated sludge ( ie the sludge, which is settled in secondary sedimentation tank, receiving effluents from aeration tank)

• Oxidation ponds etc. Since all these aerobic units generally make use of primary settled sewage,  they are easily classified as secondary units.