Deutsch: gelöschter Kalk / Español: cal apagada / Português: cal hidratada / Français: chaux éteinte / Italiano: calce spenta

Slaked lime (also known as calcium hydroxide) is a chemical compound with the formula Ca(OH)₂. In the context of the environment, slaked lime is used for various purposes, including water treatment, soil stabilization, and pollution control, due to its alkaline properties and ability to neutralize acids.

Description

Slaked lime is produced by adding water to quicklime (calcium oxide, CaO), a process known as slaking. The reaction is exothermic and results in a white, powdery substance that is highly reactive. Slaked lime is commonly used in environmental management for its ability to neutralize acidic substances and precipitate contaminants.

The use of slaked lime dates back to ancient civilizations, where it was employed in construction and agricultural practices. Today, its environmental applications are diverse and critical for maintaining ecological balance and human health.

Special Considerations

Slaked lime must be handled with care as it can cause skin and eye irritation upon contact. Proper storage and usage guidelines are essential to ensure safety and effectiveness in environmental applications.

Application Areas

Slaked lime is utilized in several environmental areas, including:

• Water Treatment: Used to adjust pH levels, soften water, and remove impurities such as heavy metals and organic compounds.
• Soil Stabilization: Applied to improve the engineering properties of soil, making it suitable for construction and agriculture.
• Air Pollution Control: Helps to reduce emissions of sulfur dioxide (SO₂) from industrial processes by neutralizing acidic gases.
• Waste Treatment: Used in the treatment of sewage and industrial effluents to neutralize acids and precipitate contaminants.
• Agriculture: Enhances soil quality by neutralizing acidic soils and providing essential nutrients like calcium.

Well-Known Examples

• Water Treatment Plants: Slaked lime is added to water to control pH and remove impurities, ensuring safe drinking water.
• Flue Gas Desulfurization (FGD): Used in power plants to remove sulfur dioxide (SO₂) from exhaust gases, reducing air pollution.
• Soil Improvement Projects: Applied to stabilize and neutralize acidic soils in agriculture, promoting healthy crop growth.
• Sewage Treatment Facilities: Utilized to treat wastewater by neutralizing acids and facilitating the removal of contaminants.

Treatment and Risks

Slaked lime's environmental applications come with certain risks and challenges:

• Health Risks: Direct exposure can cause skin and eye irritation, respiratory issues if inhaled, and gastrointestinal problems if ingested.
• Environmental Risks: Overuse or improper application can lead to soil and water alkalinity, negatively impacting plant and aquatic life.
• Handling and Storage: Requires careful handling and proper storage conditions to prevent moisture absorption and ensure safe use.

Examples of Sentences

• "The water treatment facility uses slaked lime to neutralize acidic impurities and improve water quality."
• "Farmers often apply slaked lime to acidic soils to enhance crop growth and soil health."
• "The power plant employs a flue gas desulfurization system that uses slaked lime to reduce sulfur dioxide emissions."
• "Proper handling of slaked lime is essential to avoid health risks associated with skin and eye contact."
• "Environmental engineers recommend the use of slaked lime for stabilizing contaminated soils at construction sites."

Similar Terms

• Quicklime: Calcium oxide (CaO), a precursor to slaked lime used in similar applications.
• Hydrated Lime: Another term for slaked lime, emphasizing its water content.
• Limewater: A saturated solution of calcium hydroxide in water, used for similar purposes.
• Calcium Carbonate: A related compound often used in conjunction with slaked lime for environmental applications.

Summary

Slaked lime, or calcium hydroxide, is a versatile chemical widely used in environmental management for water treatment, soil stabilization, air pollution control, and waste treatment. Its ability to neutralize acids and precipitate contaminants makes it invaluable for maintaining ecological balance and human health. However, proper handling and application are crucial to mitigate potential health and environmental risks.

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