What type of waste discharge into a sewer can create a toxic atmosphere?

Cyanide waste from metal finishers can create a toxic atmosphere when discharged into a sewer. This is because cyanide is a highly toxic chemical that can pose significant health risks to humans and aquatic life. When cyanide is introduced into wastewater systems, it can react with other substances and create hazardous gas emissions, leading to potential toxicity in confined spaces like sewers. Additionally, if these discharges reach treatment facilities, they can inhibit the biological processes needed to treat wastewater effectively, further compounding environmental and safety issues.

In contrast, the other types of waste mentioned typically do not create a toxic atmosphere to the same extent. Acid waste can be harmful, but it primarily affects infrastructure rather than creating toxic gases. Phosphate-rich waste can contribute to algal blooms in water bodies but does not pose immediate toxic risks in a sewer environment. Food waste, while it can lead to odors and bacteria, also doesn’t create a toxic environment like cyanide does.