Polycyclic aromatic hydrocarbons (PAH) are organic substances defined as homologues of benzene.These hydrocarbons are thanks to the industry and fossil fuels combustion a common part or environment. PAH are carcinogenic and toxic. There are hundreds of varieties and their properties depend on their molecular weight.

Limit in the water is max: 0,04 mg/l.

Examples

anthracene, acenaphtylene, naphtalene, acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, indeno(1,2,3- c,d)pyrene and benzo(ghi)perylene.

Pure compounds of these hydrocarbons are white, occasionally slightly yellow solid matters of a crystalic character with a difficult solubility in water. In oils and fats the dissolve well.

Health risks of aromatic hydrocarbons

Cancer, reproduce faults and mutations to animals, threat to a healthy evolution of a fetus, irritation or burn to the skin.

A huge source of a benzo(a)pyrene are cigarettes. Each one brings cca 25 ng of this substance into the smoker.

Removal of aromatic hydrocarbons from water

Removal of aromatic hydrocarbons is done by the method of coagulation or sorption. Sorption of these elements from water means catching of them on a surface of a solid phase. That is done either by chemical sorption or adsorption.