How to Fix Hard Water

How to fix hard water is a major question of water treatment or water purification process.  Water hardness test is a process of removing undesirable chemicals, materials and biological contaminants such as suspended particles, dissolved particles, iron content, bacteria etc. from contaminated water.  Most water is purified for human consumption (drinking water) in the world but water purification may also be designed for variety of others purpose, including meeting the requirements of medical, pharmacology, chemical, textile and other industrial applications. A typical water treatment procedure for industrial use : Sand Filter,  Duel media filter,  Multi grade filter, Oxidation chamber, activated carbon water filter resin water filter, water softener hardness setting, Reverse osmosis system is used when it is required to remove TDS in large extent. Depending on hard water data treatment scheme is designed to submit economical offer to ensure desired quality of treated water.

Sand Filter:

Sand filter is the primary step of WTP- water treatment process for collecting pure water system from water hardness. Sand filter remove water substance from water. Sand filter remove iron from hard water and it is used for water purification.  This is very old technique so at present it is not developing broadly.

Types of  Sand Filter :

There are three main types.

1. Rapid sand filters
2. Up flow sand filters
3. Slow sand filters

Maine use of pressure Sand filter:

1. To reduce the suspended solids very rapid level
2. To remove the odor
3. To get crystal clear water in outlet
4. To reduce the turbidity

Activated Carbon Water Filter:

Activated carbon water filter is a method of filtering that uses a bed of activated carbon to remove contaminants and impurities, using chemical adsorption to provide pure water systems.  The activated carbon water filter is most fruitfull at removing chlorine, sediment and volatile organic compounds from water from water hardness. This process of activated carbon water filter remove water hardness by water hardness test

Resin Water Filter:

Resin water filter is widely used in different separation, purification, and decontamination processes which remove water hardness from watersoft. Resin water filter works like sandfilter.

Water Treatment Process gives pure water systems from water hardness

How do Water Softeners Work:

Water softener hardness setting is an ion exchange technique by which hardness of water is removed to supply pure water. Ion exchange is the process of water softener hardness setting to supply pure water system. This water softener hardness setting process of ion exchange will continue until all available exchange sites are filled at which point the resin is exhausted and must be regenerated by suitable chemicals.

Soft Water Store Tank :

This is a tank where soft water is stored after softner filter.

Total hardness

Burette

0.02 n edta solution

Conical flask

 X ml of sample

• 2-3 drops ammonia  buffer solutions
• Pinch of drops of eriochrome black-t

Titration

Sample   vs    0.02 n edta  solution

Endpoint

Pink color changed to sky blue

Calculation

Titration value ×0.02 ×50×1000

X ml of sample

X ml	Titration value	Calculation-ppm
25	A	Ax40
50	B	Bx20
100	C	Cx10

Calcium hardness

Burette

0.02 n edta solution

Conical flask

• X ml of sample
• 2-3 drops 1 n naoh solution
• Pinch of muroxide indicator

Titration

Sample  vs    0.02 n edta solution

Endpoint

Pink color change to purple

Calculation

 Titration value ×0.02 ×50×1000

X ml of sample

X	Titration value	Calculation- ppm
25	A	Ax40
50	B	Bx20
100	C	Cx10

Magnesium hardness

Total hardness – calcium hardness – ppm

 Total alkalinity-methyl orange alkalinity

Burette

 0.02 n sulfuric acid solution

Conical flask

• X ml of sample
• 2-3 drops methyl orange indicator

 Titration

Sample vs    0.02 n sulfuric acid solution

Endpoint

Golden yellow to red orange color

Calculation

Titration value ×0.02 ×50×1000

X ml of sample

X	Titration value	Calculation
25	A	Ax40
50	B	Bx20
100	C	Cx10

 Phenolphthalein alkalinity

 Burette

0.02 n sulfuric acid solution

 Conical flask

• X ml of sample
• 2-3 drop of  phenolphthalein indicator
• Appearance of pink color

Titration

Sample  vs 0.02 n sulfuric acid solution

 Endpoint

Disappearance of pink color

Calculation

                 Titration value ×0.02 ×50×1000

                          X ml of sample

X	Titration value	Calculation- ppm
25	A	Ax40
50	B	Bx20
100	C	Cx10

Acidity

 Burette

0.02 n sodium hydroxide solution

 Conical flask

 X ml of sample

• 2-3 drop of  phenolphthalein indicator
• Solution is colorless

Titration

Sample  vs 0.02 n sodium hydroxide solution

Endpoint

Appearance of pink color

Calculation

 Titration value ×0.02 ×50×1000

X ml of sample

X	Titration value	Calculation- ppm
25	A	Ax40
50	B	Bx20
100	C	Cx10

Free residual chlorine

Burette

 0 .025 n sodium thio sulfate solution

Conical flask

•  ml of sample
• 5 drop of 100 % acetic acid
• Pinch of potassium iodide
• 2-3 drops of starch indicator
• Solution turns blue

Titration

  Sample vs 0 .025 n sodium thio sulfate solution

 End point

Disappearance of blue color

Calculation

Titrate value x 0.025×35.45×1000

X ml of sample

X	Titrate value	Calculation-ppm
20	A	A x 35.45
50	B	B x 17.7
100	C	C x 8.8

Chloride

Burette

0.027 n silver nitrate solution

Conical flask

• 5 ml of sample
• 4-5 drops of potassium dichromate as a indicator

 Titration

Sample  vs 0.027 n silver nitrate solution

Endpoint

Yellow color to brick red

Calculation

Titrate value x 0.027×35.45×1000

X ml of sample

X	Titrate value	Calculation-ppm
2.5	A	Ax382.86
5	B	Bx191.43
10	C	Cx95.715

Delivery Pump :

Soft water is sent to different section like dyeing and washing from soft water store tank. To ensure smooth running of both process and machinery distribution of water to the system has to be at the right quantity and the pressure. Water Treatment by means of reverse osmosis requires high pressure and accuracy. Regulation must be a fast and smooth response to change in operating conditins – e.g. Clogging. In order to meet this we have developed a unique mix and match approach – for example customized pumps that can handle high inlet pressure.

Engr. Kh. Mashiur Rahman, Garments Auto Machine Technologist, Web: www.autogarment.com, Email: autogarments@gmail.com, Cell: +88 017 92 52 53 54