Desal Supplies

Unit 9, Canal Street Works

Rochdale, Lancs, OL11 1AB

Tel: +44 (0)1706 869777 / Email:

Membrane fouling groups together a range of contaminants which all result in a reduction in membrane performance.  Typically these include metal oxides such as iron and manganese, colloidal material such as alumino-silicates, bio-films and organic matter.


Bio-fouling - accumulation of microorganisms (bacteria, algae & fungi) on the membrane surface resulting in the formation of biofilms. Specialist attention should be paid to alkaline cleaning, antiscalant selection, pre-treatment & shutdown procedures.


Iron is a common type of foulant found on membrane surfaces.  Sources of iron include naturally occurring iron in most feed waters, overdosing of ferric based coagulants and corosion products from distribution systems.


Alumino-silicate (clay) - naturally occurring colloidal particles, which haev not been removed by the pre-treatment system. It is difficult to remove from lead elements due to impermeability.


Aluminium membrane fouling can often occur as a result of excessive dosing of aluminium coagulants and poor operation of the filtration system.  It is very difficult to remove from the membrane surface.


Manganese is less common than iron fouling.  When water containing manganese is oxidesed, insoluble colloidal hydroxide particles are formed.