Filters: The unsung heroes

Water is a universal solvent. It is vital to life from drinking, to manufacturing processes, washing, cleaning, and its essential applications in science - the list is endless. It is easy to take safe and clean water for granted; filtered water ensures we can conduct reliable experiments, consume safe and great tasting food and drink. If this process is disrupted or compromised in any way it can wreak havoc.

This three part blog will explore what water filtration is, its importance, the implications for unkept filters and will take a glimpse into the underworld of counterfeit filters.

What do filters do?

Industrial filtration involves the removal of contaminating particles. Filtering unwanted impurities such as sediment, hardness and bacteria result in better quality water. Filters are used across several different industries: pharmaceutical, food and beverage, cosmetic and chemical.

Types of filter and how do they work?

There are five types of filters: dead-end, absorption, sequestration, ion exchange and reverse osmosis filters.

Dead-end filtration:

Sediment, dirt or particles are physically removed using a barrier. Mechanical filters could be a basic mesh which filters larger particles or if you need an ultra-fine filtration, you can use a ceramic filter with complex pore structures.


Carbon is highly effective at capturing water-borne contaminants. Chemical impurities, like chlorine, are trapped in its huge internal surface.


This process chemically isolates a substance.

Ion exchange:

This is where one or more undesirable ionic contaminant is removed from water by exchange with another non-objectionable ionic substance. This process is used to soften hard water by exchanging the magnesium and calcium ions found in hard water with other ions such as sodium or hydrogen ions.

Reverse osmosis:

This process filters water by using a semipermeable membrane to remove dissolved inorganic solids, like magnesium ions. This is a highly effective way to purify water and can be combined with other methods, such as using a mechanical filter.

No electricity required! Water pressure forces water through the membrane.

Measuring filter efficacy

Mechanical filters normally provide a micron rating. This rating indicates how effective the filters are in relation to the size of the particles it can remove. Common ratings include:

5 micron – will remove most particles visible to the naked eye

1 micron – will remove particles only visible with a microscope

0.5 micron – will remove cysts