Primary Stage of Wastewater Treatment

by Reid Burns in January 31st, 2023

The first "primary" stage of wastewater treatment simplified and explained.

A wastewater problem can develop in runoff water created by an array of uses. We have explained this in our what is wastewater blog post. When a wastewater issue happens the first type of treatment is called the "Primary Stage." We have broken down each wastewater stage here, but by request wanted to go deeper into the Primary treatment stage.

The easiest way to understand the primary treatment in a wastewater system is the removal of TSS (total suspended solids). This happens by running the water via a pump through a solid removal process. Some popular processes and systems involved here are Screens, Jet Aeration, Dissolved Air Flotation, and Oil and Water Separators. These systems all can remove larger solids, and then be run through a secondary treatment or discharged. Here at bioprocessH2O we help build DAF units, which are one solution for primary wastewater treatment.

DAF units: DAF units bubble up any solids in the wastewater. These solids are then disposed as sludge into a sludge tank, which is then brought to a landfill. This first separation of the solids and water happens within the DAF unit.

DAF Blog

Screening Systems: This is usually installed at the beginning of any wastewater system where solids are present. These screening systems remove any large solids, and then pass the contaminated water as effluent through to a DAF, oil and water separator or secondary system then for discharge.

Oil and Water Separators: These systems work thanks to Oil and Water density levels. Under certain conditions (which these systems optimize for) oil and water can be separated. This is thanks to Stokes' Law, which explains that Oil is lighter than H2O.

The next stage in wastewater process is the secondary stage. Something like bioprocessh2o's MBBR systems or MBR systems are then used to remove BOD and COD through filtration or biological treatment. If you have any questions on wastewater treatment or the stages involved please do not hesitate to reach out via the form below.



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