Which statement about the lime-soda ash process characteristics is correct?

Which statement about the lime-soda ash process characteristics is correct?

• A. softens water at a moderate cost
• B. it can be used for both groundwater and surface water
• C. it is most often used at small treatment plants
• D. all of the above

Answer: (B)

The main idea is that lime-soda ash softening is a versatile chemical method that can handle different water sources because it targets hardness and related minerals regardless of whether the water comes from groundwater or surface water. Adding lime precipitates calcium and magnesium as insoluble compounds, and adding soda ash helps remove silica and adjust alkalinity, allowing the process to reduce hardness across a variety of waters. This flexibility is why the statement that it can be used for both groundwater and surface water is correct. The other points don’t fit as neatly. The lime-soda ash process tends to involve significant chemical usage and sludge handling, which makes it less of a low-cost option and more suited to larger treatment facilities rather than small plants. Therefore, while it’s effective, it isn’t typically described as being used at small plants, and the cost isn’t reliably just moderate across all situations.

The main idea is that lime-soda ash softening is a versatile chemical method that can handle different water sources because it targets hardness and related minerals regardless of whether the water comes from groundwater or surface water. Adding lime precipitates calcium and magnesium as insoluble compounds, and adding soda ash helps remove silica and adjust alkalinity, allowing the process to reduce hardness across a variety of waters. This flexibility is why the statement that it can be used for both groundwater and surface water is correct.

The other points don’t fit as neatly. The lime-soda ash process tends to involve significant chemical usage and sludge handling, which makes it less of a low-cost option and more suited to larger treatment facilities rather than small plants. Therefore, while it’s effective, it isn’t typically described as being used at small plants, and the cost isn’t reliably just moderate across all situations.