Preliminary Treatment – A treatment process consisting of screening and grit removal before the wastewater flows on to other treatment processes.
Primary Treatment – A treatment process that usually consists of clarification by solid-liquid separation that removes a substantial amount of suspended and floating matter.
Secondary Treatment – A treatment process that uses biological processes utilizing bacteria to remove pollutants.
Tertiary Treatment – A treatment process that uses physical, chemical, or biological processes to remove suspended solids and nutrients in wastewater to accomplish a level of treatment greater
than what can be achieved by secondary treatment.
Headworks – Headworks is the beginning, or head, of a treatment plant where influent flow is measured and sampled and where preliminary treatment occurs.
Grit – The fine abrasive particles removed from wastewater, such as sand and eggshells.
Detritus – Combination of grit (inorganics) and organics.
Screenings – The materials in wastewater that are removed on screens at the headworks of treatment plants, such as sticks, stones, plastics, and personal hygiene products.
Aeration Basin – A tank in which wastewater is aerated to achieve biological treatment.
Clarifier – A circular or rectangular tank used to remove floatable and settleable solids in wastewater.