What is lime soda treatment process?
Lime softening (also known as lime buttering, lime-soda treatment, or Clark’s process) is a type of water treatment used for water softening, which uses the addition of limewater (calcium hydroxide) to remove hardness (deposits of calcium and magnesium salts) by precipitation.
What is hot lime soda process?
The warm lime softening process operates in the temperature range of 120-140°F (49-60°C). The solubilities of calcium, magnesium, and silica are reduced by increased temperature. Therefore, they are more effectively removed by warm lime softening than by cold lime softening.
What is the function of lime and soda in lime soda process?
Chemical precipitation is one of the more common methods used to soften water. Chemicals normally used are lime (calcium hydroxide, Ca(OH)2) and soda ash (sodium carbonate, Na2CO3). Lime is used to remove chemicals that cause carbonate hardness. Soda ash is used to remove chemicals that cause non-carbonate hardness.
What is the difference between hot lime soda process and cold lime soda process?
1-Hot lime soft drink process is done at high temperature (95-100°C) ,while cold lime soft drink process is done at room temperature (25-30°C). 4-In hot lime soft drink process filtration is simple as consistency of water is low, yet in virus process filtration isn’t simple.
What is soda and lime?
Soda lime is a mixture of NaOH & CaO chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO2 retention and carbon dioxide poisoning.
How can CaCO3 be reduced in water?
The general recommendation to prevent CaCO3 precipitation is to lower the water pH by acid injection. Using chemical can be very expensive. Also, chemicals are harmful for environment and health. Magnetic process as a physical method can be alternative to the chemicals in order to decrease precipitation of CaCO3.
Why coagulants are used in cold lime soda process?
If process is carried out at room temperature it is called cold lime soda process. Coagulant is necessary because at room temperature precipitate is finally divided. But do not settle easily & cannot easily filtered.
Which coagulants is used in cold lime soda process?
Use of sodium aluminate as coagulant also helps the removal of silica as well as oil, if present in water. Cold L-S process provides water, containing a residual hardness of 50 to 60 ppm.
What is the basic principle applied to remove the hardness of water by lime soda process?
Lime soda process: In lime-soda process, hard water is treated with lime (CaO or Ca (OH)2) firstly, after that with soda. In this process, the hardness is removed by sedimentation as calcium carbonate or magnesium hydroxide. The usual method for lime soda processing is treatment by excessive lime amount.
What are the advantages and disadvantages of lime soda process?
It is slow process because reactions during water softening takes place in very dilute solutions and room temp. It does not give soft water having residual hardness less than 50-60 ppm. It requires coagulant for setting particles of ppt.
Why coagulants are used in cold lime soda method?
If process is carried out at room temperature it is called cold lime soda process. Coagulant is necessary because at room temperature precipitate is finally divided. But do not settle easily & cannot easily filtered. i) Reactions take place faster.
How soda lime is formed?
Soda lime is a granular solid created by slackening quicklime (CaO) with a concentrated arrangement of sodium hydroxide, NaOH(aq). In substance reactions, Soda lime does act as sodium hydroxide yet, in contrast to sodium hydroxide, it isn’t deliquescent and doesn’t attack glass.
What is lime soda process?
Introduction Lime Soda process is a method of softening hard water. This process is now obsolete but was very useful for the treatment of large volumes of hard water. In this process Calcium and Magnesium ions are precipitated by the addition of lime (Ca (OH)2) and soda ash (Na2CO3). 2 3/3/2014 3. What is Lime Soda Process?
Why is cold lime soda not suitable for all purposes?
The cold lime soda process is not suitable for all purposes. It is limited for those purposes where partially softened water needed because this process fails to precipitate completely all the hardness forming salts. The cold lime soda process is used for municipal water and cooling water softener systems.
What is cold lime softening used for?
Cold lime softening, also known as Clark’s process, is used to reduce raw water hardness, alkalinity, silica, and other constituents. This helps prepare water for direct use as cooling tower makeup or as a first-stage treatment followed by ion exchange for boiler makeup or RO Reject recycle.
What happens when you mix lime and soda ash?
The water is treated with lime or a combination of lime and soda ash (carbonate ion). These chemicals react with the hardness and natural alkalinity in the water to form insoluble compounds. The compounds precipitate and are removed from the water by sedimentation/clarification.