Heat

             MnO2    +    4HCl            ———————–>    MnCl2   +  Cl2   +   2H2O

The chlorine thus liberated is a strong-smelling,greenish-yellow gas with a pungent odor ; it is extremely irritating to mucous membranes.

Chlorine is in the group of Hydrogen family. Chlorine is the most unusual and versatile chemical, since its properties different from its stages like Gaseous, Liquid and aqueous. For that reason only its each states will be treated separately.

1. CHLORINATION of SWIMMING POOL
2. Chlorination of waste water
3. Chlorination of portable water
4. Chlorination of cooling water

Chlorinaton

1. Healthy
2. Safety  and
3. Aesthetics

It is in interest of public health that the pool be disinfected to prevent the transmission of disease. It is in the interest of swimmers safety that water be free of turbidity or color so that the bottom of pool at its greatest depth is visible at all times. It is in the interest of aesthetics that the pool be immaculately clean. This means the absence of film,scum leaves, surface debris and aquatic growth such as algae. Therefore the prime requisites of swimming pool operation must result in water that is clear and sparkling and free from bacteria and algae. The water should be of drinking quality , nonirritating and free of objectionable odors or tastes. In addition the pool structure must be free of film and deposits.

• Total Dissolved Solids              : Less than 2000 mg/l
• Hardness                                       : 200 – 400 mg/l
• pH Range                                      : 7.4 – 7.8
• Total Alkalinity                         : 80 – 150 mg/l

Sanitizer Level

1. Free chlorine                : 1.0 – 3.0 mg/l     (OR)
2. Bromine                          : 2.0 – 4.0 mg/l    (OR)
3. Biguanides                    : 30 -50 mg/l

              1. Disinfection: 

                70 % Calcium Hypochlorite granual type is used in  swimming pool to maintain chlorine level.

• Low chlorine level  leads to algal and bacterial growth, waterborne illnesses, cloudy water and insufficient sanitation of the water.
• High chlorine level  leads to eye, nose and skin irritations.

             We have to keeping Swimming pool Free Available Chlorine (FAC) in between 1.0 to 2.0 ppm.

           2.  pH Adjustment:

The human eye have a just slightly basic pH value of 7.35. so we have to keep in range with proper pH levels in our pool to avoid eye  irritation,itching and other various problems. For human safety we have to keep in level of the pH in our pool.

To maintain pH in balance we adjust the water with additions of pH increasers (bases) or pH de-creasers (acids) to achieve the range of  7.2 – 7.8.

               We have to keep swimming pool water pH 7.4

 High pH:

 When we analyse High pH we reduce with any following  acids.

1.Muriatic Acid ( 30 % Hydrochloric Acid Liquid )                                                         

2.Dry acid (Sodium Bisulfate – granule or powder )

 Low pH:  

 In conditions of Low pH it should be balanced with range of 7.2 to 7.8 .This is attained with an Alkali – Soda Ash (Sodium Carbonate).

            3. Algaecide (Copper Sulfate)

                Adding Algaecide in our swimming pool to prevent algae growth or destroy algae.

            4. Stabiliser:

                Adding Cyanuric acid (isocyanuric acid) to stabilize the chlorine level.  We have to keep  stabiliser level in the range of  40-80 ppm

           5. Alkalinity:  

pH is alkaline dependent,that is, alkalinity is defined as the ability of the water to resist changes in pH. Alkalinity keeps the pH from “bouncing”.We are maintaining alkalinity in the 80-120 ppm range for our pools to increase alkalinity.We are using Sodium bicarbonate and decreasing alkalinity we are using Dry acid (Sodium Bisulfate)

          6. Flocculation  ( Coagulation ):

We are adding Flocculant chemicals to bind or stick,tiny particles together, resulting in larger clumps which settle to the bottom of the pool and leave the water clear. These “clumps” can be easily removed by vacuuming the floor of the pool.

           7. Shock Treatment ( Super Chlorination ): 

                We are adding 5- 10 ppm Chlonine to pool and shock 24 – 48 hrs to get complete disinfection.

 When  Chlorine level  is  so  high that bacteria, virus, larwa  or anything micro organic matters in the pool water is completely destroyed.

Shock Treatment  can mainly  do  addition to oxidizing undesired wastes  and  used to rid the pool of algae and bacteria that might be hiding in filters and hard to sanitize all areas. Superchlorination also gets rid of chloramine odor.

          8. Backwasing:

Sand filters trap dust and dirt, as the name implies, in a bed of sand. When the filter has accumulated a large amount of dirt, the water cannot pass freely through the sand and the filter loses efficiency as the pressure increases. Backwashing sends water backwards through the filter and flushes the trapped dirt out. 

           9.  Adding Fresh Water:

We are adding with fresh water  reducing  Calcium Hardness , Cyanuric Acid Level

and  Total Dissolved Solids (TDS)

         10. Water Analysis: 

            pH, TDS, Free Chlorine,Combine Chlorine , Total Chlorine, Total Alkalinity, Calcium Hardness and Temperature.