Wastewater level monitoring in sewage treatment plants
When the sewage arrives via the sewage network, the sewage treatment plant relies on level monitoring to allow the process to operate correctly. Wastewater level monitoring in sewage treatment plants is an essential control parameter for numerous sedimentation basins, settling tanks, aeration basins and clarifiers that are involved in the sewage treatment process.
The wastewater is first screened to remove debris that may damage the treatment plant such as rags, timber, grit or stones that all may have been carried with the wastewater. The sewage will then flow into various chambers for equalisation, desilting, grease separation, mixing, aeration, chlorination, flocculation, sedimentation, etc. Wastewater level monitoring in sewage treatment plants is required in most of these stages for accurate liquid level control.
Many older sewage systems combine storm water run-off with sewage which could overload the treatment plant, thus equalisation chambers are used to buffer the treatment plant from such sudden excessive liquid volume. This additional volume can then be treated as soon as the wastewater volume returns to normal flow levels. Wastewater level monitoring in sewage treatment plants is therefore used to ensure these tanks or basins are not overwhelmed and to continuously check the amount of sewage buffered in the equalisation tank.
Resistant submersible pressure transmitters for waste water level monitoring
Further on, the location of the treatment plant must also be considered - in case it is located near the sea or a chemical plant some water coming in to the plant may be contaminated with sea water, brine or even chemicals. Wastewater level monitoring in sewage treatment plants and fluid pressure monitoring at pumps or valves should therefore be undertaken by using submersible pressure transmitters or level sensors manufactured from materials resistant to these potentially contaminated liquids.
A sewage treatment plant will also have tanks storing chemicals to add to the wastewater in the treatment process. Industrial wastewater uses PH neutralisation processes to neutralise the acid or alkaline properties of the liquid. Hydrostatic level sensors are combined with diaphragm seals if required for material compatibility and are fastened to the bottom of these tanks to measure the level of the chemicals in the storage tanks for inventory control.
Ultimately the treated water is returned to the natural environment, into streams, rivers, groundwater or the sea.