Chemical Handling and Storage Flashcards

Alum (aluminum sulfate) is commonly added during water treatment primarily for what purpose?

Answer: Coagulation and flocculation of suspended particles

Alum acts as a coagulant, causing fine suspended particles to clump together into larger floc that can be removed by sedimentation or filtration.

Polymer chemicals used in water treatment should be stored to avoid which of the following conditions?

Answer: Freezing temperatures and direct sunlight

Polymers can degrade or freeze if exposed to very low temperatures, and UV light from direct sunlight can break down their molecular structure.

When a chemical delivery is received at the treatment plant, what should the operator verify FIRST?

Answer: The chemical matches the purchase order, container labels, and SDS

Verifying that the delivered chemical matches the purchase order and labeling ensures the correct chemical is received and prevents dangerous mix-ups.

Calcium hypochlorite (HTH) stored at a water treatment facility presents which primary hazard?

Answer: It is an oxidizer that can ignite organic materials and some metals

Calcium hypochlorite is a strong oxidizing agent that can react violently with organic materials, fuels, and some metals, creating a fire or explosion risk.

What does a GHS diamond-shaped pictogram with a flame symbol on a chemical label indicate?

Answer: The chemical is flammable or an oxidizer

Under the Globally Harmonized System (GHS), a flame pictogram indicates the substance is flammable, self-reactive, self-heating, or an oxidizer.

Which chemical is typically used at water treatment plants to raise the pH of finished water for corrosion control?

Answer: Sodium hydroxide (NaOH) or lime (Ca(OH)2)

Sodium hydroxide (caustic soda) and lime are alkaline chemicals commonly used to increase water pH and reduce the Langelier Saturation Index for corrosion control.

What is the purpose of a chemical feed day tank at a water treatment plant?

Answer: To hold a working supply of chemical solution and allow safe, controlled dosing

Day tanks provide a manageable, intermediate volume of chemical solution from which metering pumps can draw for accurate and safe dosing into the treatment process.