What chemical is used for dechlorination?

What chemical is used for dechlorination?

• A. Sodium Bicabonate
• B. Hydrochloric Acid
• C. Sodium Bisulfite
• D. Sodium Chloride

Answer: (C)

The use of Sodium Bisulfite for dechlorination is rooted in its ability to effectively neutralize chlorine in wastewater. Chlorine is commonly used as a disinfectant, but it must be removed before the treated wastewater is discharged into the environment to prevent harm to aquatic life and ecosystems. Sodium Bisulfite reacts with chlorine to form sodium sulfate and hydrochloric acid, effectively eliminating residual chlorine. This process is crucial because residual chlorine can be toxic to fish and other aquatic organisms. The dosage of Sodium Bisulfite must be carefully controlled to ensure complete dechlorination without over-adding, which can lead to the formation of other potentially harmful byproducts. Other choices presented do not serve this function in wastewater treatment. Sodium Bicarbonate is often used to adjust pH, Hydrochloric Acid is a strong acid that can alter water chemistry significantly, and Sodium Chloride is simply table salt, which does not dechlorinate and can lead to increased salinity in water bodies. Thus, Sodium Bisulfite is the appropriate choice due to its specific effectiveness in dehalogenating wastewater.

The use of Sodium Bisulfite for dechlorination is rooted in its ability to effectively neutralize chlorine in wastewater. Chlorine is commonly used as a disinfectant, but it must be removed before the treated wastewater is discharged into the environment to prevent harm to aquatic life and ecosystems. Sodium Bisulfite reacts with chlorine to form sodium sulfate and hydrochloric acid, effectively eliminating residual chlorine.

This process is crucial because residual chlorine can be toxic to fish and other aquatic organisms. The dosage of Sodium Bisulfite must be carefully controlled to ensure complete dechlorination without over-adding, which can lead to the formation of other potentially harmful byproducts.

Other choices presented do not serve this function in wastewater treatment. Sodium Bicarbonate is often used to adjust pH, Hydrochloric Acid is a strong acid that can alter water chemistry significantly, and Sodium Chloride is simply table salt, which does not dechlorinate and can lead to increased salinity in water bodies. Thus, Sodium Bisulfite is the appropriate choice due to its specific effectiveness in dehalogenating wastewater.