ABSTRACT
Polycyclic aromatic hydrocarbons (PAHs) are aromatic hydrocarbons with two or more fused benzene rings originating from natural and anthropogenic sources. PAHs are widespread environmental contaminants in aquatic environments and mainly originate from fossil fuel combustion and from the release of petroleum and petroleum products (Tian et al. 2009, Jung et al. 2010, Timoney and Lee 2011). The PAHs have attracted environmental concern due to their ubiquitous occurrence, recalcitrance, bioaccumulation
CONTENTS
6.1 Fate and Removal of PAHs and VOCs in MBRs .................................... 116 6.1.1 Critical Parameters That Affect PAH Removal ......................... 124
6.2 Results from Selected Case Studies in Italy and Greece ...................... 131 6.2.1 Italian Case Studies ....................................................................... 131
6.2.1.1 Occurrence, Removal, and Fate of Aromatic VOCs ..... 131 6.2.1.2 Occurrence, Fate, and Removal of PAHs ..................... 132
6.2.2 The Greek Case Studies ................................................................ 132 6.2.2.1 Occurrence, Fate, and Removal of Aromatic VOCs ... 132 6.2.2.2 Occurrence, Removal, and Fate of Aromatic PAHs ... 133
6.3 CASP vs. MBR (Overall Evaluation) ........................................................ 134 6.4 Conclusions ................................................................................................. 135 Acknowledgments .............................................................................................. 135 References ............................................................................................................. 135
potential, and carcinogenic activity (Haritash and Kaushik 2009). Some PAHs with four or more benzene rings, such as benzo(a)anthracene, chrysene, and benzo(a)pyrene, can generate covalent DNA adducts and oxidative DNA lesions, resulting in mutagenic and carcinogenic effects (Cao et al. 2010, Arp et al. 2011). Moreover, PAHs are persistent in the environment and can cause long-term adverse effects (Liu et al. 2010, Patrolecco et al. 2010). PAH emissions in many countries have continuously increased owing to their rapid growth in energy consumption and the increase of traffic and shipping (Guo et al. 2010, Liu et al. 2010, Malik et al. 2011). Recently, accidents have released millions of barrels of oil containing massive amounts of PAHs into water bodies, such as in the Gulf of Mexico (Crone and Tolstoy 2010) and in the port of Dalian in China (Guo et al. 2009), causing significant damage to marine and freshwater ecosystems. As a result of the widespread use of PAHs and their adverse impacts on water ecosystems and human health, their removal from aquatic systems is of essence.
