Water Treatment

Water treatment includes treating wastewater to be discharged into a water body and treating raw water from a water body to be used.  The World Health Organization has guidelines for water quality that are used around the world, but most areas have additional rules as well.  Canada has a set of guidelines, which are not as strictly followed or as stringently determined as the legislature in the US.

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Water Purification (for drinking and other uses)

Toledo: Collins Park Water Treatment Plant

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Wastewater Treatment (for release into public water)


Toledo: Bay View Wastewater Treatment for water reclamation

FINE BAR SCREENS AND PUMP STATIONS
Screens remove debris to prevent clogging and protect pumping equipment. Pump stations transport raw sewage to the treatment plant.

AERATED GRIT TANKS
Remove five to ten tons of grit (sand, gravel, and other heavy solids) daily for landfill disposal.

OIL AND GREASE SKIMMING TANKS
Collect and transfer floatables to scum separation tanks. The sludge settles to the bottom and is pumped to the sludge thickeners.

PRIMARY CLARIFIERS

Add polymer to the water to allow more solids to settle to the bottom and floatables to rise to the surface. Floatables are skimmed and sent to a landfill. Solids are pumped to the digester tanks.

AERATION TANKS

Mix air with wastewater to promote growth of aerobic microorganisms which help to break down organic matter.

FINAL CLARIFIERS

Encourage floc, which contains microorganisms and organic material, to settle, leaving clarified water on the surface. This process creates return activated sludge, which is sent to the aeration tanks, and waste activated sludge, which is sent to dissolved air floatation.

CHLORINE CONTACT TANK

Mixes chlorine with clarified water to provide disinfection before discharge into the Maumee River (required April 1st to October 31st).


CONTROL ROOM
Allows plant personnel to monitor and control treatment processes via computer. Computers also track the plant’s performance for documentation in monthly operating reports.

GRAVITY THICKENERS
Thicken raw primary sludge prior to placement in the Digester Storage and Mix Tank. Dilution water (final effluent) is added to keep the tanks from becoming septic. Thickener effluent is returned to the secondary tanks.

DISSOLVED AIR FLOATATION

Adds polymer to waste activated sludge and mixes it with pressurized water. Solid floatables are skimmed and pumped to the digesters. Remaining water flows back to the aeration tanks.

ANAEROBIC DIGESTERS

Biologically stabilize sludge using anaerobic bacteria. This process produces methane gas, a source of energy for the plant.


BELT FILTER PRESSES
Add polymer to the sludge from the digesters. Sludge is then dewatered in belt filter presses, and sent to the biosolids reuse programs. Remaining water is returned to the aeration tanks.


Toledo Information:  all from Toledo, Ohio’s Public Utilities website