Which device is used to grind solids to about 0.3 cm or smaller before treatment?

• A. Comminutor
• B. Headworks
• C. Detritus
• D. Phosphorus remover

Answer: (A)

A comminutor is used to grind solids to about 0.3 cm or smaller before treatment. In the headworks, it macerates large solids—like rags or plastics—into smaller pieces, reducing the chance of clogging pumps and screens and making subsequent treatment steps more efficient. Headworks is the overall area that includes initial screening and grit removal, not the grinding device itself. Detritus refers to debris present in the flow, not a device, and a phosphorus remover is a chemical treatment step for removing phosphorus, not size reduction.