Removal of polycyclic aromatic hydrocarbons in aqueous environment by chemical treatments: A review

• PAHs are present in aquatic ecosystems and affect human health and living beings.
• Conventional water treatments can be unsuccessful in the PAH degradation.
• AOPs and their simultaneous combination generally result in high PAH conversions.
• AOPs coupled with biotreatments could be a cost-effective solution for PAH removal.

Due to their carcinogenic, mutagenic and teratogenic potential, the removal of polycyclic aromatic hydrocarbons (PAHs) from aqueous environment using physical, biological and chemical processes has been studied by several researchers. This paper reviews the current state of knowledge concerning PAHs including their physico-chemical properties, input sources, occurrence, adverse effects and conventional and alternative chemical processes applied for their removal from water. The mechanisms and reactions involved in each treatment method are reported, and the effects of various variables on the PAH degradation rate as well as the extent of degradation are also discussed. Extensive literature analysis has shown that an effective way to perform the conversion and mineralization of this type of substances is the application of advanced oxidation processes (AOPs). Furthermore, combined processes, particularly AOPs coupled with biological treatments, seem to be one of the best solutions for the treatment of effluents containing PAHs.