The main difference between carbonate and non-carbonate hardness is that carbonate hardness involves the presence of bicarbonate and carbonate ions in water, whereas non-carbonate hardness consists of the remaining hardness in water after carbonate hardness has been removed.
Carbonate and non-carbonate hardness are aspects of water quality that impact various industrial processes, household activities, and environmental factors.
Key Areas Covered
1. What is Carbonate Hardness
– Definition, Features
2. What is Non-carbonate Hardness
– Definition, Features
3. Similarities Between Carbonate and Non-carbonate Hardness
– Outline of Common Features
4. Difference Between Carbonate and Non-carbonate Hardness
– Comparison of Key Differences
5. FAQ: Carbonate and Non-carbonate Hardness
– Frequently Asked Questions
Key Terms
Carbonate Hardness, Non-carbonate Hardness, Permanent Hardness, Temporary Hardness
What is Carbonate Hardness
Carbonate hardness is a specific type of water hardness that is primarily associated with the presence of bicarbonate and carbonate ions. These ions are derived from the dissolution of bicarbonates and carbonates of calcium and magnesium in water. Carbonate hardness is often referred to as temporary hardness due to its unique behavior upon heating.
The primary sources of carbonate hardness are minerals containing carbonate and bicarbonate ions, such as calcium carbonate and magnesium carbonate. These minerals can be found in geological formations, and their dissolution into water contributes to their hardness. Additionally, carbonate hardness can also be introduced through the decay of organic matter, which releases bicarbonate ions. Carbonate hardness is typically measured in terms of alkalinity, which represents the ability of water to neutralize acids. Alkalinity is often expressed in terms of milligrams per liter (mg/L) or parts per million (ppm) of calcium carbonate equivalent. The measurement involves titrating the water sample with a strong acid until the bicarbonate and carbonate ions are neutralized, leading to a change in pH.
Carbonate hardness holds significance due to its wide-ranging impact on industrial processes, household functions, and environmental considerations. It plays a crucial role in causing scaling issues in water heaters, pipes, and appliances, as the precipitation of calcium carbonate during heating leads to scale buildup, reducing efficiency. Additionally, high carbonate hardness can diminish the effectiveness of soaps and detergents, forming soap scum and impacting lathering ability. In agriculture, carbonate hardness in irrigation water can alter soil properties, affecting soil structure and nutrient availability. Moreover, in aquatic environments, elevated carbonate hardness levels can influence the pH of natural waters, providing buffering capacity crucial for stabilizing pH in aquatic ecosystems, although excessive levels can lead to undesirable pH shifts.
What is Non-Carbonate Hardness
Non-carbonate hardness (NCH), often referred to as permanent hardness, arises from the presence of divalent metal ions other than calcium and magnesium that are not associated with bicarbonate and carbonate ions. Common contributors to non-carbonate hardness include sulfate, chloride, and nitrate ions of calcium and magnesium.
The primary sources of non-carbonate hardness are minerals and salts containing sulfate, chloride, and nitrate ions of calcium and magnesium. Unlike carbonate hardness, non-carbonate hardness does not exhibit a behavior of precipitation upon heating and is considered “permanent” in the sense that it persists in water even after boiling. Non-carbonate hardness is typically measured as the residual hardness in water after carbonate hardness has been removed. The total hardness of water can be determined by titration methods, measuring the concentration of divalent metal ions using complexometric titrations. The difference between total hardness and carbonate hardness gives the value for non-carbonate hardness.
The presence of non-carbonate hardness in water brings various consequences and impacts on industrial processes, water treatment, and daily activities. Furthermore, it contributes to the formation of scale deposits on surfaces like pipes and appliances, reducing equipment efficiency and increasing maintenance costs. Similar to carbonate hardness, non-carbonate hardness interferes with the effectiveness of soaps and detergents, diminishing lathering ability and cleaning efficiency. Moreover, high levels of non-carbonate hardness can lead to corrosion in metal pipes and equipment, impacting the integrity of the infrastructure through the formation of corrosion products.
Similarities Between Carbonate Hardness and Non-Carbonate Hardness
- Both contribute to the total hardness of water.
- Both carbonate and non-carbonate hardness contribute to the formation of scale deposits in water systems, affecting pipes, heating elements, and appliances.
- Moreover, they can interfere with the action of soaps and detergents, reducing their effectiveness and lathering ability.
Difference Between Carbonate Hardness and Non-Carbonate Hardness
Definition
Carbonate hardness is a specific type of water hardness that is primarily associated with the presence of bicarbonate and carbonate ions, while non-carbonate hardness is part of water total hardness that is not caused by carbonates but mainly by anions of sulfate.
Origin
Carbonate hardness arises from the presence of bicarbonate and carbonate ions, primarily derived from the dissolution of bicarbonates and carbonates of calcium and magnesium. On the other hand, non-carbonate hardness arises from divalent metal ions, primarily calcium and magnesium, associated with ions other than bicarbonate and carbonate.
Precipitation
Moreover, carbonate hardness exhibits a behavior of precipitation upon heating, while non-carbonate hardness does not exhibit precipitation upon heating.
Removal
Carbonate hardness can be removed by methods that target the precipitation of carbonates, such as boiling or lime softening. However, non-carbonate hardness requires different treatment methods, as boiling or lime softening is not effective.
FAQ: Carbonate Hardness and Non-Carbonate Hardness
What is an example of non-carbonate hardness?
The presence of calcium sulfate is an example of non-carbonate hardness.
What is another name for non-carbonate hardness?
Permanent hardness is another name for non-carbonate hardness.
What are non-carbonates?
Non-carbonates are chemical compounds that do not contain carbonate ions. They include substances like sulfates, chlorides, and nitrates.
Conclusion
The main difference between carbonate and non-carbonate hardness is that carbonate hardness involves the presence of bicarbonate and carbonate ions in water, whereas non-carbonate hardness consists of the remaining hardness in water after carbonate hardness has been removed.
Reference:
1. “Carbonate Hardness.” Wikipedia. Wikipedia Foundation.
Image Courtesy:
1. “Glass of Water” (CC0) via Pickpic
Leave a Reply