ENVIRONMENT|deterioration of the environment|waste|wastewater · ENVIRONMENT|environmental policy|pollution control measures
- umar síothlaithe phríomhúil Tagairt Faomhadh an téarma seo mar chuid de Thionscadal Lex
- ga
- primary settlement tank
- en
- Sainmhíniú tank designed to reduce the velocity of the wastewater flow, allowing heavier organic solids (called raw sludge) to settle Tagairt "Partech. Primary Settlement Tank (PST) (8.5.2019)"
- Nóta They are the first stage of treatment after the removal of rags and grit in the inlet works. Scrapers present in the tank move continuously along the floor of the tank to deposit the raw sludge in hoppers for removal. The scum which floats to the surface is directed by water jets or scum boards to the sludge sump. The raw, settled sludge is removed by pump or gravity feed to a sludge treatment process, either on site or via tanker to a larger processing centre. Approximately 60% of suspended solids and 35% of BOD removal efficiency can be achieved at this stage.