An Introduction to Environmental Chemistry

136 Chapter Four

Naphthalene Phenanthrene Benzo[b]fluoranthene

Fluorene Anthracene

Benzo[k]fluoranthene Dibenzo[a,h]anthracene

Acenaphthene Crysene

Acenaphthylene Pyrene

Fluoranthene Benzo[a]anthracene

Benzo[a]pyrene Benzo[g,h]perylene

Indeno[1,2,3-c,d]pyrene

Fig. 4.32Sixteen PAHs listed as priority pollutants by the US Environmental Protection Agency.

Benzene Catechol

2 Meta cleavage

1 Ortho cleavage COOH

COOH

Cis, cis-muconic acid

OH

OH

1

2

2-Hydroxymuconic

semialdehyde

COOH

OH

COH

Fig. 4.33Aerobic biodegradation pathways for benzene.