Dolomite (calcium dolomite) or limestone is used to make lime, a manufactured commodity (calcium magnesium carbonate). To produce quicklime and hydrated lime, the raw material is treated. Because of its alkaline nature, it is often used in the process of modifying the pH of acidic environments such as water and soil. It is put to use in the treatment of both potable water and wastewater.
Lime products that are often used in the treatment of water
Plain calcium carbonate or magnesium carbonate can be changed in a few ways to make products with different chemical properties and different uses. Calcination refers to the process of heating calcium carbonate, which results in the release of carbon dioxide and the formation of calcium oxide. This is how quicklime is produced. Crushing quicklime and combining it with a trace quantity of water will result in the production of hydrated lime, sometimes referred to as slaked lime and consisting of calcium hydroxide. This further processing step may be done to produce calcium hydroxide.
Lime is Used in the Water Softening Process
“Hard” water often has dissolved mineral components in it, such as calcium and magnesium, which are removed during the softening process. However, the procedure employs chemical interactions in a high pH environment to generate calcium compounds which precipitate into solids, and these particles may be filtered out of the water. As an example, calcium bicarbonate and lime both react to produce calcium carbonate and water.
Lime in the Treatment of Municipal Wastewater
When lime is added to sewage water, it elevates the pH, which may lead to algal blooms, much like water softening does. Calcium phosphates, a solid precipitated from water, are formed when lime and phosphorus mix in a high pH environment. The same high-pH environment is used in the process known as “ammonia stripping,” which results in the release of gaseous nitrogen into the atmosphere in the form of ammonium hydroxide.
Utilization of Lime in the Treatment of Industrial Wastewater
Acidic wastewater (https://en.wikipedia.org/wiki/Wastewater) is a byproduct of a wide variety of industrial operations, including mining, steel manufacturing, and fruit canning. This wastewater must be cleaned before being released into the environment. With its acid-neutralizing properties, lime also precipitates certain metals into solids, which are then collected for further use. Lime, a less caustic alternative to caustic soda, is more cost-effective and safer to use, and its sludge is more effective in capturing metals than caustic soda’s sludge.
Chemical processes are used to remove dangerous compounds and germs from the water used in households, companies, and industries. After chemical treatment, the water is safe to return to the source. There are a few different chemicals that may be used in the process of water treatment, including chlorine, lime, and hydrogen peroxide. When it comes to the treatment, each approach has a unique set of benefits and drawbacks to offer.
Before chlorinated drinking water was used around the turn of the century, cholera, typhoid fever, dysentery, and hepatitis killed thousands of Americans each year. Chlorination continues to be the technique of choice for disinfecting public drinking water supplies and swimming pools in the modern day.
Chlorination helps limit the spread of illnesses like E. coli and eliminates undesirable tastes and smells from drinking water. Even though chlorination is an excellent method for disinfecting drinking water, working with it may be challenging for those who lack the necessary knowledge and experience. Chlorinated water may dry out skin and hair, cause eye discomfort, and fade clothes.
Lime
Hard water is characterized by large concentrations of dissolved minerals, which, when they accumulate in water pipes and other internal systems, may lead to clogging and other forms of long-term harm. The use of water softeners that are produced with hydrated lime has been shown to alleviate water quality issues such as hard water and lower the amounts of harmful arsenic found in drinking water.
Lime not only changes the pH of the water, but it also acts to remove the conditions that are necessary for bacteria and viruses to thrive in an environment. Visit https://www.carmeuse.com/lime-slurry to learn more about the changes lime slurry causes during water treatment. Lime softening may sometimes result in pH values that are too high for the environment. When lime is added to water that has been chlorinated, a disinfectant called hypochlorite is formed. This disinfectant is not as effective as other free chlorine residuals, but it does remove harmful bacteria.
Hydrogen Peroxide
The usage of hydrogen peroxide, which is a bleaching chemical, may result in lighter hair, whiter teeth, and lighter colors in fabrics and textiles. It removes contaminants and inhibits bacterial development to disinfect water. Hydrogen peroxide is harmless, leaves no residue or gas, and may eliminate chlorine residue following chlorination. Because exposure to hydrogen peroxide may irritate the eyes, skin, lungs, and mucous membranes, the material has to be carried and handled with extreme caution.
