sewage treatment in cork and munster
 

Washdown & Silt Separator

Separators serving wash-down areas such as car wash and other cleansing facilities must discharge directly into a foul drain, which feeds to a municipal treatment facility.
Such wash down facilities must not be allowed to discharge directly into either surface water or any oil/water separator discharging into surface water as they utilise emulsifiers, soaps and detergents, which can dissolve and disperse the oils and upset the separation process.

Silt separators can be used as a supplementary unit to remove additional silt before other Separators or treatment units. If emulsifiers are present the discharge must not be allowed to enter a NS class 1 or class units

Applications
These units can be used to serve vehicle wash down areas and car wash facilities, although it should be noted that the prime function of such separators is for the removal of silt.
Typical locations using wash down separators are; - Car wash, tool hire depots, truck cleansing, construction compounds cleansing points. Locations requiring silt separators are; - Highly silted sites where NS separators are used, i.e. works constructions sites and temporary work compounds.

Operation
As contaminated water passes through the separation chamber, it is retained long enough to allow immiscible hydrocarbon pollutants, such as oils and petrol to accumulate on the surface of the water and settleable solids to sink to the bottom of the unit. Our design uses a maximum of 6 minutes retention time, at the flow rate given. The separator water is able to discharge safely without the risk of oil pollution to the municipal plant. It is generally accepted that greatest separation efficiency for oil is gained by using a single chamber separator as the pollutants have more time to separate.

The nature of the silt varies depending on either the ground or surface receiving the flow. These aspects should be considered when selecting the size of the unit in relation to the flow being treated.

Washdown Separator PDF