Fabric Filter
A cloth device that catches dust particles from industrial emissions. See also Bag Filter.

FID
Flame Ionisation Detector.

Flare
A control device that burns hazardous materials to prevent their release into the environment; may operate continuously or intermittently, usually on top a stack.

Floc
A clump of solids formed in sewage by biological or chemical action.

Flocculation
Process by which clumps of solids in water or sewage aggregate through biological or chemical action so they can be separated from water or sewage.

Flue Gas Desulphurisation
A technology that employs a sorbent, usually lime or limestone, to remove sulphur dioxide from the gases produced by burning fossil fuels.

Flue Gas
The gas coming out of a chimney after combustion in the burner it is venting. It can include nitrogen oxides, carbon oxides, water vapour, sulphur oxides, particles and many chemical pollutants.

Flue
An enclosed structure through which gases travel.

Fluidised Bed Incinerator
An incinerator that uses a bed of hot sand or other granular material to transfer heat directly to waste. Used mainly for destroying municipal sludge.

Fluidised
A mass of solid particles that is made to flow like a liquid by injection of water or gas is said to have been fluidised.

Fluorides
Gaseous, solid, or dissolved compounds containing fluorine that result from industrial processes.

Fluorocarbons (FCs)
Any of a number of organic compounds analogous to hydrocarbons in which one or more hydrogen atoms are replaced by fluorine. They are now found mainly in coolants and some industrial processes. FCs containing chlorine are called chlorofluorocarbons (CFCs). They are believed to be modifying the ozone layer in the stratosphere, thereby allowing more harmful solar radiation to reach the Earth’s surface.

Fly Ash
Non-combustible residual particles expelled by flue gas.

FOCS
Fibre Optic Chemical Sensor

Food Chain
A sequence of organisms, each of which uses the next, lower member of the sequence as a food source.

Formaldehyde
A colourless, pungent, and irritating gas, CH20, used chiefly as a disinfectant and preservative and in synthesising other compounds like resins.

Fossil Fuel
Fuel derived from ancient organic remains, e.g., peat, coal, crude oil, and natural gas.

Friable
Capable of being crumbled, pulverised, or reduced to powder by hand pressure.

Fuel Efficiency
The proportion of the energy released on combustion of a fuel that is converted into useful energy.

Fuel Switching
A pre combustion process whereby a low-sulphur coal is used in place of a higher sulphur coal in a power plant to reduce sulphur dioxide emissions.

Fugitive Emissions
Emissions not caught by a capture system.