What chemical is commonly used to treat laundry wastes?

Hydrochloric acid is often used in the treatment of laundry wastes particularly for the purpose of pH adjustment and to break down organic materials. Laundry wastes can contain various substances, including detergents and other residues, which may require neutralization to optimize conditions for biological treatment processes. Hydrochloric acid effectively lowers the pH of alkaline wash waters, creating a more neutral environment that can enhance subsequent treatment steps, such as biological treatment.

In contrast, while other chemicals like sodium hydroxide, chlorine gas, and acetic acid have their specific uses in wastewater management, they are not typically used for the treatment of laundry wastes. Sodium hydroxide is an alkaline substance useful in certain cleaning processes, chlorine gas is primarily a disinfectant, and acetic acid is often used as a pH adjuster in other contexts but not specifically for laundry wastewater treatment. Thus, hydrochloric acid stands out as a commonly utilized chemical in this specific application.