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Filter medium

The permeable material that separates solids from liquids passing through it.


A liquid that has passed through the filter medium.


Separation of a solid and a liquid by using a porous substance that only lets the liquid pass through.

Final effluent

Typically, the effluent discharged from a treatment plant after completion of treatment of a domestic or industrial wastewater.

Fine screen

A bar screen or wire mesh.


A flocculent mass that is formed in the accumulation of suspended particles. It can occur naturally, but is usually induced in order to be able to remove certain particles from wastewater.


The accumulation of destabilized particles and micro flakes, and subsequently the formation of sizeable flakes. One must ad another chemical called flocculent in order to facilitate the formation of flakes called flocs.


The flat or nearly flat land along a river or stream that is covered by water during a flood.


A solids-liquid or liquid-liquid separation procedure, which is applied to particles of which the density is lower than that of the liquid they are in. there are three types: natural, aided and induces flotation.


Application of fluoride to drinking water at the request of health authorities as a preventive measure against dental decay.

Foul flooding

Flooding from a sewer.

Foul sewer

A sewer conveying sewage, ie wastewater of domestic or industrial origin, excluding rainwater or surface water.

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