Grit removal systems are generally classified into three categories:
| Name | Solid removal | Size of opening | Pretreatment? |
|---|---|---|---|
| Coarse screen | Large objects | 6–150mm | No |
| Fine screen | Fine solids | <6 mm | Yes. These will remove fine solids that MRSL compounds may be absorbed into. |
| Micro screen | Majority of solids |