The theoretical dosage of sulfur dioxide for dechlorination is what, per 1.0 mg/L chlorine residual?

The theoretical dosage of sulfur dioxide (SO2) required for dechlorination specifically correlates with the amount of residual chlorine present in the wastewater. For every 1.0 mg/L of chlorine, the theoretical requirement for sulfur dioxide is approximately 0.9 mg/L. This relationship exists because sulfur dioxide acts as a reducing agent that chemically reacts with chlorine to neutralize its effects, making it an effective dechlorination agent in wastewater treatment processes.

This dosage is based on stoichiometric calculations of the chlorine-sulfur dioxide reaction, which allows precise dosing to mitigate chlorine levels without leaving excess chemicals in the effluent. By understanding this dosage, wastewater operators can effectively manage chlorine residuals, ensuring compliance with discharge regulations and promoting environmental safety. Thus, the understanding of the dechlorination process alongside the required dosage provides insight into maintaining optimal wastewater quality.