Polycyclic Aromatic Hydrocarbons

Cathal Walsh
Content Creator
Friday, 21st June 2019
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Maximum allowed in water:

   0.1 μg/litre

What are polycyclic aromatic hydrocarbons [PAH]?

These are defined as ‘a group of organic compounds containing two or more fused aromatic rings of carbon and hydrogen atoms’. Natural crude oil and coal deposits contain significant amounts of PAHs. They are also found in processed fossil fuels, tar and various edible oils.
This is one of the most widespread organic pollutants. They are also formed during the incomplete combustion of fuels such as wood, coal diesel etc.  High concentrations of PAH’s occur in smoked foods and in the burnt fat of meats.


Are they in the source?

Unless there has been a contaminations incident PAH’s should not be in the source.

How do they get into water?

PAH exceedances in water suggest that a carbon based pollution incident has occurred.  This could be either because of contamination at the source or infiltration of the contaminant at some other stage.

Do they pose a risk to health?

The international agency for research on cancer has stated that PAH’s are probably carcinogenic.

What to check for?

Ensure that there is no activity in the area of a water source or water treatment that may lead to PAC contamination.  Also it is essential to ensure that chemicals used in the water treatment process come from a reliable source.

How Do I remove it from my water?

The two best methods for removing PAH’s from water are either the process of coagulation, settling and filtration or using a granular activated carbon filter.

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